High Altitude PAX disscussion

[AlexR]

Hello Reno SCCA Members!

After reading about HAP (high altitude pax) And thinking it through I was first thinking it was a great idea. But when i sat down to really think it over I started to realize while it’s a noble idea, it would be exceedingly difficult to come up with a factor that would adequately take into account all of the factors that come into play. After more analysis I don't even think Its an issue with in certain classes. how could this be ? read on :

How does attitude change my cars power?

First we need to think about how a car makes power. The power your car makes is from burning gas. Basically your car uses all of the available O2 and burns a large % of the gas sprayed in . (excess fuel is sprayed in for cooling purposes, this extra fuel burns with O2 available in a solid form in your catalytic converter)
So basically the more Air the more power the less air the less power.

Sea level atmospheric pressure is 14.696 PSI (1) and the air pressure at 5,000 feet is about 12.23 PSI (1) so our air pressure is only 82% of normal.
So for naturally aspirating cars you can expect to lose about 18% of your power. What about a super or turbo charged car?

Force air induction vehicles use an air compressor (turbo , or super charger) to add a set amount of PSI. (unlike a Turbo Prop airplane , which adds a varying amount of PSI depending on altitude so that certain air craft run at 15 PSI from 0 feet to 20K or 30K at which point the turbo starts to taper down to lower boost leves )
The Motor on these cars suck in air that is at a higher air pressure, then their naturally aspirating counterparts. For example an Impreza WRX STI has 14.5 psi of boost. So at sea level during peak boost the car runs at 29.2 total PSI! What is the affect of high altitude on the STI? In terms of total PSI lost, its exactly the same, 2.46psi lower, or it will run at a max of 26.7 which is 91.5% of its sea level power.
The Evo 8 & 9 boost around 19 PSI (4) and thus they run at about 92.8% of seal level power. The chevy colbolt uses 12 psi of boost , so it ends up at 90.7 % of its sea level power. A mini cooper S runs at about 10 psi (89% of its sea level power) and so on..

So we could come up with a penalty index for each boost level right? Right , well no the total power generated is not = total power your car can put down. If you take a RWD high HP car (like a corvette) even with racing slicks these awesome cars can Spin their rear tires if the driver tries to accelerate too quickly. Basically any time the driver does not have his throttle over 82% open , he’s not being affected by the loss of horse power, Just when the driver is WOT (wide open throttle) well this is the same for all cars right?

Not so, other cars such as the All Wheel Drive STI can be driven using 100% throttle with out spinning the tires. So depending on course design these 2 cars may battle each other and get the same results as if they were at sea level. Actually If the high HP RWD never used over 82% of his throttle , and the STI drove around at WOT, the high HP RWD car has an advantage at high altitudes !! (Science is often stranger than fiction!) For cars that never can spin their tires, even at sea level (think a Street prepared Miata with Wide racing slicks) The miata will be at a disadvantage when trying to compete in overall PAX versus high horse power cars who rarely can use 100% of their power.

So if someone wanted to correct this , they would need to come up with an attitude factor and then they will have to adjust it for every boost level, also we will have to take into account Drive train (if wheel spin is ever possible ) , and total time spent at WOT. We could do this right and be done? Well no

I’ve used the term “peak boost” quite a few times. that’s because the air compressor has to Spin up to a certain speed (depending upon engine rpm) to give peak boost. Super charged cars have their air compressor connected via a pulley and always create a set amount of PSI per RPM of the motor. A turbo car uses exhaust gases to spin up its air compressor. So anytime you are not on the gas pedal your turbo spools down, and your boost level goes does. And when you press on the gas pedal in a turboed car there is a delay before the turbo is felt at all (this is called Turbo Lag) Depending upon the course lay out a given car may never hit peak boost , or he may be at peak boost for 40% of the course. It really just depends.

Mike K's STI has a Big Turbo on it, some courses he never sees peak boost, he might not even be hitting 15 psi on some courses due to such great lag.

So could there be combinations of course + cars + driver where the NA driver was not affected by the loss of power? Yes actually its possible, think about an overly tight course where a Z06 on streets is never going to be able to go WOT !

Are there courses where a forced induction car is not being assisted by its compressed air , Its possible, but personally think its highly unlike that a forced air induction car ever runs a course at high altitude where the air compressor would not help out, It’s also just as impossible that these cars are driving the entire course at peak boost (unless we go for a 20' long straight course!)

Also to muddy the waters is the black art of LFB a turboed car. WTF is that you ask? if you hold down your gas pedal, but you also press down your brake pedal, the car slows down, but the Turbo spools up , then when you release the brake you start off at a higher boost than if you got off the gas completly during braking. (1, this is probably bad on the car, 2, this usually results with me missing my Apex by about 30 feet as i oooh and aaah that my boost level stayed a few psi higher)

So In my opinion trying to alter PAX factors for altitude is so complicated that even the most meticulous attempt is bound to be very, very inaccurate. While PAX isn’t perfect , there are less variables to take into account then trying to adjust PAX for Cars and Tires, Than comparing altitude and boost levels.

I would conclude HAP has more complexity then PAX.

This leads me to think it will end up more flawed no matter how hard we try.

Alex Rademacher

Sources :

1)http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html (http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html)
2)http://www.caranddriver.com/comparisons/9043/2005-mitsubishi-lancer-evolution-mr-edition-v-2005-subaru-impreza-wrx-sti.html (http://www.caranddriver.com/comparisons/9043/2005-mitsubishi-lancer-evolution-mr-edition-v-2005-subaru-impreza-wrx-sti.html)
3)http://www.theautochannel.com/news/2005/04/12/036407.html (http://www.theautochannel.com/news/2005/04/12/036407.html)
4)http://autos.aol.com/article/power/v2/_a/2005-mitsubishi-evolution-mr/20061030194809990001

[jim.gandy]

First off, :):):) to you, Alex, for opening up this thread. It was bound to happen sooner or later, and I appreciate the thought and time you put into your opening post.

I'm the guy who is behind HAP, the High Altitude Performance indexing system. So, since you've basically said I'm wasting my time, I hope you'll let me respond.

First off, I hope everyone understands that HAP is a work-in-progress. I formulated it in 2006, tracked our events with it in 2007 (making some changes as the year progressed), and I intend only to continue with "testing and evaluation" in 2008. As I did last year, I'll make the results available to anyone who's interested.

Okay, now to respond...

It's all well and good to delve into engineering and physics to try to understand how altitude affects PAX. It's a reasonable thing to do -- I encourage everyone to revisit John Evans' excellent three-part series in our newsletter, Road & Tach, April-May-June 2006 (I hope Scott gets the "archival" part of the new website on-line soon).

IMO, you first need to take one step backward and consider PAX itself. PAX has been around so long that people treat it like gospel. It also gains a certain mystique by being the product of somebody way far away, somebody we can't speak with. So, we just accept PAX.

But, I believe we MUST at least think about what PAX is, what it's based on, and how accurate it is.

Do I believe that engineering and physics went into the formulation of PAX? That is, was some analysis of vehicle performance (like your analysis, Alex) used to come up with PAX factors? NO! I think it's clear that PAX was and still is based on a numerical analysis of results from some number of some type of events.

Numerical analysis of past events is, I believe, only part of the PAX story. I think it's also clear -- even though we may not want to believe it -- that PAX also incorporates good old guessing. It certainly seems to me that the Wizard of PAX must use some discretion when considering results that may have been affected by weather, he must use some discretion when deciding how many past years to include in the working data, and he must use some degree of judgment when confronted with a new class or a class whose car mix has substantially changed. And so on -- there are many, many variables that can't be controlled and thus are subject to judgment.

Look, the bottom line is, somebody somewhere cooked up some numbers and called them PAX factors. Maybe they're spot-on, maybe not -- there is no way you or I are in a position to say either way. It's really hard for some people to accept, but I believe it's the only reasonable conclusion.

The ONLY way PAX (or any other indexing system) can be judged is by this simple criteria: Does it work? That is, are the results it provides satisfactory? Or to be specific, when PAX says Driver A is better than Driver B, do you believe it?

This could end up being the longest post in history, so, no more running on. Instead, I'll just lay out the rest of the path that might lead to HAP.

If HAP is to succeed, here's what I've got to do:
Step One: Help people to understand that PAX is more guesswork than we like to admit
Step Two: Try to forge a concensus that a reasonably accurate indexing system is of value to Reno Region
Step Three: Get people to admit PAX is way off at Reno's altitude
Step Three: (PAX) + (an estimate of altitude effects) = HAP
Step Four: Track Reno Region events using both PAX and HAP
Step Five: Make changes to HAP's programming as necessary
Step Six: Let people make up their own minds AFTER they see the results

Let me repeat: The ONLY way an indexing system can be judged is: DOES IT WORK? I'm convinced PAX does not work here. I'm trying to create an indexing system that will work better for us. It is based partially on results data, partially on an understanding of engineering, and partially on pure guesswork -- JUST LIKE PAX!

And, HAP would have one very distinct difference for us: The "wizard" would be right here. You could "see the sausage being made," if you wanted to.

So, Alex, thanks for starting this thread. Even if you've decided a high-altitude indexing system is impossible, I'm going to continue trying. And, I'm going to continue to ask you (and everyone) to keep an open mind.

[Kevin M]

Jim, I think anybody that argues with the validity of what you intend to do doesn't really understand what you're attempting. I personally think every point you made in your post is a good one. Unfortunately, Reno Region simply can't provide with enough data, in quality and quantity, to publish unequivocally "close enough" results. This is due partially to limited total entries in our events, but mostly due to the lack of "maximum attack" driver/car/class combinations. Mark and Debbie qualify in their BS Mazdas, obviously a certain BSP Corvette, arguably Jay's Corvette, and a handful of other cars are fully prepped to their rules. Unfortunately, we have zero high-end prepped cars (thus far) in any class above ASP/STU. There are some good SM and Prepared cars, but none are on the level of the podium finishers at Nationals. So no matter how good your analytical process is for developing HAP numbers, you're just not going to get enough good input to be able to rely on the output as gospel, or even as good enough because we can't quantify just how much slower our better car/driver combos are than the theoretical maximum for the class. The only helpful suggestion I can come up with is maybe check for other sites in other regions that are somehwere between, say, 4500 and 5500 feet of elevation and add them in? Colorado, parts of New Mexico and Arizona, maybe Wyoming, maybe some regions in the Adirondack/Catskills areas could be analogous to our sites?

[sperry]

I think Kevin was alluding to this a little bit: no matter what we do regionally, our pool of drivers is too small to make a local PAX adjustment anything more statistically meaningful than a plain old handicap for the faster drivers.

If you go fast, inevitably those that are slower are going to make excuses. Unfortunately, no matter how justified or how grounded in science those excuses may be (I firmly believe that the altitude here tweaks the classes, though I don't know how unfair things really are) the only way to address them ends up being to make changes to right specifically addressed "wrongs". We saw this in the street tire / race tire debate. The example that kept coming up was the comparison of John and Randy in AS. And even though there's plenty of scientific merit to why the ST factor was wrong, because we can't quintify how wrong it is, the change we made came back to basically saying "Randy should have beat John, here's a number that makes that happen".

The same thing will happen with a HAP factor. Because we cannot get statistically meaningful data to calculate a factor, it's going to boil down to looking at perceived injustices in the results and creating factors that correct the results. This isn't necessarily bad or wrong if all those involved are okay with it, but it's also certainly not "fair" as it's a form of favoritism for the perceived underdog without quantifying how under the underdog is. In short, we're just going to tell some folks "you didn't deserve your win because your car works too good here", or "we think you're a better driver than the results indicate, so we're making next season easier for you".

A while back I tongue-in-cheek proposed a PAX based directly on driver performance... the autocross equivalent of victory weight as used in road racing. In my opinion, if we're willing to go down the road of modifying PAX based on local results under the guise of science, why don't we just take the next step and explicitly and transparently do it based on the results? If you do well, you should know that next time it's going to be harder for you to stay out front. Sure there'll be the possibility of sandbaggers, but you can't sandbag all season long and expect to win the handicap championship. The goal would be to come up with some level of homeostasis where the most consistently fast drivers with the handicap championship. I think most everyone will agree the "best" driver is the driver that gets the most out of their car at every event, right? Anyone that improves too much over the course of the season, or has frequent "off" days, isn't the "best" driver for that season, and that's what people think the PAX championship should be... some way to fairly pick out the best of the best for that season.

I'm sure with some thought we could put together a handicapping system that makes battles close and sorts out who's the best a lot more easily than we could ever come up with a rooted-in-physics HAP that does the same.

[jim.gandy]

Kevin, when I read your post, I get the impression that like Alex, you're focused on the difficulty of trying to replace PAX. Alex talks about the theory of high-altitude-effects, and you talk about the shortage of real-world data.

I can't argue with anything either of you says, I just think you're looking at it from the wrong angle.

The point I was trying to make in my post is that PAX is a combination of data and guesswork, and HAP is also a combination of data and guesswork. Ergo, the proof of the pudding HAS TO BE in the tasting: does HAP provide event rankings that are more satisfactory than PAX at this altitude?

Kevin, you say no -- without referencing any HAP results. That doesn't seem right to me. Have you seen the 2007 HAP results? They were circulated at one of our meetings (January, I think). There's a sheet for each of our 17 events showing the HAP rankings alongside the PAX results for easy reference, and there's a year-end points standings, too. I can give you a full set, if you like. That offer goes for anyone. It can be e-mailed, but it's over a megabyte, and I'm still on dial-up...

It's my intention to make HAP results available after every event this year. The board of directors has said it's okay to use the website. I'll be getting with Scott to see whether it would be better to have a separate section or to simply use a forum thread.

The goal of HAP has never been results that are "unequivocally 'close enough'" (your words, Kevin). The goal of HAP is "better than PAX at our altitude." HAP needs at least one or two more years of experience, but I personally think its results are already better than PAX. I've inviting everyone to take a look and tell me what they think. I'm also more than willing to let people see my methods -- and if someone is inspired to pick up the ball and run with it, leading to an even better indexing system, that would be great.

[sperry]

The goal of HAP is "better than PAX at our altitude." HAP needs at least one or two more years of experience, but I personally think its results are already better than PAX. I've inviting everyone to take a look and tell me what they think. I'm also more than willing to let people see my methods -- and if someone is inspired to pick up the ball and run with it, leading to an even better indexing system, that would be great.

When you say that HAP results are already better than PAX, how can you tell? The answer of course is that in your judgment the people who should have placed higher in the results are in fact placing higher. But because we can't quantify anything with regards to performance the "proof in the tasting" is in fact purely opinion.

If that's the measuring stick for HAP (or PAX for that matter), then how is it different from just forming a committee and voting on who should have won each class? That would in fact be less work and likely more accurate than attempting to develop some system of numbers that manipulate the results to match expectations. The only issue is the lack of transparency... autocross becomes ice skating instead of a real sport.

My point is, any numbers system we develop that purports to level the playing field between drivers by taking everything but the driver out of the picture is really just a trumped up version of victory by committee, because when it all comes back to deciding if PAX or HAP is working, we end up looking at the drivers and making a judgment call about what we think should have happened.

I think any really useful handicapping system will have to taking into account that we'll never pick out the best driver by separating them from their environment. But after all, that's real racing. When you win at LeMan, it's not a driver that wins, it's several drivers, in a specific car, at le Sarth on a specific day, with weather and luck, and all that factored into the win. So why is it in autocross that people are so hung up about losing because their car isn't fast enough? How is that unfair to them when there's nothing preventing them from getting a different car? Or more importantly, how is it fair to handicap the person that did pick the faster car for making what would normally be considered the right decision in motorsports?

I guess I'm kinda getting off on a bit of a non-HAP specific tangent, but I think my points are still related.

[jim.gandy]

Scott, you ask " 'When you say that HAP results are already better than PAX, how can you tell? The answer of course is that in your judgment the people who should have placed higher in the results are in fact placing higher. But because we can't quantify anything with regards to performance the "proof in the tasting" is in fact purely opinion.' "

I take exception to your asking and answering the question for me. My answer is NOT "of course... in my judgment... ". MY answer is that HAP takes into account some of the major effects that altitude has on performance, and therefore is better than PAX. After all, HAP doesn't start from scratch -- it starts from PAX and alters it to try to be more accurate/fair than PAX at high altitude. Only at the end of the day do I look at the HAP results and try to see if something's way off -- like, for example, if Scott Perry finishes in the bottom third for no apparent reason.

Scott, I know I will probably never convert you. In this discussion and in the R vs. ST controversy, you are consistent in your statements that the questions are not suited to finding numerical solutions at the regional level. Please tell me if I'm wrong, but the impression I have is that you believe these issues are 1) not quantifiable by analysis and reasoning because they're too complex, 2) not quantifiable by empirical testing because there are too many variables, AND 3) not quantifiable by data-crunching of event results because there isn't a big enough pool of apples-to-apples data.

You may be right. Then again, you may be wrong. What is the downside of fully exploring these issues and at least attempting to find solutions? Convince me that something bad will happen, and I'll stop working on HAP.

[MikeK]

... like, for example, if Scott Perry finishes in the bottom third for no apparent reason.

Actually, the smoke would be very apparent :p

OK, back to the HAP discussion ...

[Kevin M]

Scott, I know I will probably never convert you. In this discussion and in the R vs. ST controversy, you are consistent in your statements that the questions are not suited to finding numerical solutions at the regional level. Please tell me if I'm wrong, but the impression I have is that you believe these issues are 1) not quantifiable by analysis and reasoning because they're too complex, 2) not quantifiable by empirical testing because there are too many variables, AND 3) not quantifiable by data-crunching of event results because there isn't a big enough pool of apples-to-apples data..

For me, it's just #3. No matter how good your analysis is, you just aren't going to get meaningful data up here. If you were to use, say, A Stock, B Stock, ASP and BSP as baselines, you could maybe get somewhere with those. But most of the rest of the classes just don't have any entries that are national-prep cars with national-prep drivers. Take me for example. I will be running my wagon in FSP on street tires. I'll probably walk away with the class, and probably not make a real run at PAX. It's not the altitude, it's not even the level of competition. It's just that I don't have the money to make a thoroughbred out of my plowhorse, nor the time to become a truly great driver. I have to settle for being 'pretty good,' which, in my (soon-to-be) 'pretty good' car, can possibly land me on the local leaderboard at times. So if we fast forward to the end of the year, and I have strung a bunch of 10s in the class, how do you weigh me in HAP? Did I finish 15 spots too low in PAX because I'm only making 90-something % of my car's rated 142 horses, or did 4 of those spots come from my own room for improvement as a driver, and another 4 from setup and mod options I did not utilize? I am just one example; you and I both know that the majority of class winners in our region are in the exact same boat. You and Don personified it last year. You guys were fantastically entertaining to watch in ES (as were John and Randy in AS) but parity in a few classes does not create legitimacy for your results, as nobody I've mentioned thus far in this post is competitive above the regional level in the classes we run, at least partly due to underprepped cars.

So my point is this- if you assume that car A is getting an advantage over car B at Stead because of altitude, you're right. But if you then believe you can quantify that advantage using season results from our events, you're wrong. If neither car A nor car B is as fast as it could have been then you can't deduce that the margin of victory over car B is solely from the horsepower advantage. In other words, if Randy's disadvantage to John at 5042 feet is an average of X seconds per 60 in real-world results, how can you determine what percentage of that time is due to John's altitude advantage, and not due to tire selection, suspension behaviors, driving skill, driving performance on a given day, or one of the cars jsut plain being faster? Unless we get a large enough pool of built-to-the-rules cars with top-level driversin them, we can never, ever determine with any sort of accuracy what the actual disadvantage is for a normally aspirated and/or small displacement car vs. forced induction and/or large displacement because it's all mixed up with tires, mods, setup, drivers, and just plain luck.

Jim, you can get a handle to a limited degree on which cars have a larger advantage or disadvantage over another. You can use the results we generate to make observations about seemingly evenly matched cars that are always finishing in the same order, or seemingly mismatched cars that are always turning similar times. You can point to car A and car B and say that one has to be driven better than the other in order to win. But you can't claim that car A and car B demonstrate the actual value of that disadvantage when neither one can be used as the measuring stick of the class to begin with.

I have to admit, I don't really like having to argue against you about HAP Jim. It's a great idea, and you're certainly to be congrtulated for making such a large effort to provide a more level playing field so we can all shut up and race. You asked me earlier if I looked at HAP results you showed in January; I did not, because I couldn't be at the meeting that month. But even without seeing them, I am quite confident in stating that you probably made an excellent analysis of a poor representative sample of data. Your methods and motivations both deserve approval from the Region's members; but our timeslips aren't enough for you to be able to give valid conclusions yet. So I again suggest looking for regions that have sites similar to ours, that don't have radically different styles of course design (i.e Hawthorne style vs. Stockton Fairgrounds style) and then dig a little to see how many national-level cars and drivers they have. If some other region that runs at about 5,000 feet has top drivers then pool their results with ours.

[sperry]

Jim, I think Kevin echoed my sentiments fairly eloquently.

I'm certainly not attempting to admonish your work on HAP in anyway. I know hard it is to work on a system such as HAP. Take a look at the Time Trials Production rules I made up... they're virtually identical in goals as the HAP index: a method to quantify car performances based on the physical attributes of the car. To be honest, the only reason the TT classes work right nowis because the competition isn't all that tight in trials yet and because the competitors at trials don't expect to be beat by the other driver alone... if you opponent is beating you because they've got 20hp and 2" wider tires than you, that's the nature of the sport.

I find the HAP work very interesting, and would certainly like to see it continue. But I also want to make sure we fundamentally understand the issues with something like PAX or HAP, issues you yourself alluded to, like the fact that there's an element of guesswork in the system.

And my biggest point regarding the guesswork portion of the system is to remind everyone that in the end, we quantify how well the system is based on simply on "do things look right?" in the indexed standings. Whether or not you're delaying the result inspection until after the system is designed or not, it's still an essential part of the process: Let's say you build a HAP index and I do end up in the bottom three? You seem to indicate that means there's something wrong with the system and imply you'd change it, as I'm not usually one to finish so low. If the system were truly based on the science and not on personal judgment of the results, you should be telling me I deserved the bottom three finish, after all math can't lie!

It's a catch 22... if we could quantify the accuracy of the HAP index it could be used as a true impartial handicap to extract driver performance from the race results. But if we can quantify HAP accuracy, we don't need HAP, as we already have the means to directly quantify driver performance! Similarly, HAP can never be impartial because in the end, final quantification of the system's accuracy becomes plain old personal observations of the results.

I'm not saying that HAP can't be a useful system... after all PAX is a useful system and it's terribly inaccurate... and HAP should be better than PAX. But the real win comes when people stop thinking that autocross has something to do with driver skill alone and remember that motorsports is motorsports. i.e. a win takes a driver and a car. Classes and rules are just there so we can give out more than one trophy. There will always be someone with a faster car, or more skill. Luckily for those in our sport, we can always try to out-spend the competition if we can't out drive them. Other sports have to resort to steroids.

Anyway, it's late and I'm supposed to be coding... forgive my rambling.

[jim.gandy]

Posts are coming too quickly, I can't stay on top of them... :(

Kevin, you did a great job of explaining why the method you assume I used can't produce trustworthy results. BUT I DIDN'T USE THAT METHOD!

Maybe you were confused when I earlier referred to there being real-world data in HAP. The only real-world data in HAP is what's imbedded in PAX to start with (I hope we all agree that PAX is a mixture of crunched event results and educated guessing by the Wizard of PAX).

HAP takes the PAX factors and modifies them with an equation that uses factorials to produce a varying amount of adjustment across the range of classes, from A Mod to H Stock. Still with me? Okay, now how did I come up with the equation? I used the first method I listed: analysis and reasoning. "Analysis" doesn't refer to data analysis, it refers to analyzing the actual effect of altitude on vehicle performance (primarily power output) and trying to predict what that effect means in terms of autocross run times. As I said earlier, John Evans pointed the way in his series of newsletter articles.

I can't emphasize strongly enough that NO EVENT RESULTS ARE USED in calculating the HAP factors -- beyond, of course, the results imbedded in PAX itself.

I can already hear the next objections: "That kind of 'analysis' amounts to pure guesswork! And what makes Jim think he's qualified, anyway?" No, it's not guesswork, any more than Newton using his Theory of Gravity to calculate planet orbits was guesswork. It's called the Scientific Method. Develop a theory, then use it to make some predictions, then observe real-world results to see if the theory seems to hold water. Today, Newton's Theory of Gravity is accepted and used all the time, even though we still don't have a clue what really causes gravity. Ergo, you might be tempted to say Newton's Theory of Gravity still is just guesswork. But I digress... :)

Is Jim qualified? I'm no genius, but I maintain it doesn't take a genius to do this. I do have a Bachelor's and a Master's in Engineering, if that counts. Just think of me as a Mad Scientist... :D

Scott, your midnight posting gets closer to something I can agree with. But I object to your use of the phrase, "we quantify how well the system is (working) based on simply 'do things look right'." I don't purport to QUANTIFY HAP's functioning. I do, however, look at how HAP handles real-world event results to see whether anything sticks out like a sore thumb, indicating I need to go back to the analytical drawing board. And if I do make changes, they are done with full regard for the "analysis and reasoning," not simply to make a particular result look right to me. I.e., I'm altering the theory, not just jiggering the results. In my view, what I'm doing is trying to "VALIDATE the system based on 'do things look right'." Don't you think that's what happened in the early years of PAX?

Note that after a full year of "field testing," I've only changed HAP twice: once in July last year, and once in the off-season re-examination this winter (when I also updated to the 2008 PAX factors as a base). I would hardly say that qualifies as fiddling to produce a certain result. And also note that, each of the 41 classes uses exactly the same equations to calculate its HAP factors, except for one: F Stock, with more horsepower than handling, needs an additional adjustment, in keeping with the underlying theory.

To my mind, the underlying theory is standing up rather well. That's why I'm reasonably confident when I say, "HAP is already better than PAX at this altitude."

If it helps, consider that we COULD do the full "Scientific Method" thing. We could have HAP make a prediction about what would happen if two competent drivers in dissimilar cars in different classes, who historically were a certain amount apart in PAX in Sacramento, came up to Reno and ran. Believe me, I'm always on the lookout for that kind of data. I'm confident that HAP would do a good job, even considering the other variables, like course design, surface conditions, weather, who had the sniffles that day, and so on. Of course, one event is not proof. That's why the validation process takes years.

On last comment for Scott: being able to win by spending more is "lucky?" To my mind it's more like the Curse of Motorsports, especially at this level. How many Sennas and Schueys has the world never gotten a chance to see, simply because at some early stage in their development they were outspent? It ain't right. Never has been. Just my HO... ;)

[sperry]

My "lucky" comment was intended as tongue-in-cheek. But one of the cornerstones of motorsports is that equipment is just as important as driver skill (in fact in the earliest version of racing, it was nearly 100% about the equipment... just making your car last the 1000 miles of the race took a driver, a mechanic, and a ton of luck!). So, I'll agree that there are probably hundreds (if not thousands) of incredible drivers that will never get the recognition they deserve because they can't afford to go racing, but that is the nature of racing. Racing has *always* been about the car and the driver. And getting beat because you have inferior equipment, or winning because you've got a technical edge is just as valid as winning or losing on driver skill alone.

It's only in autocross that there seems to be some huge push to separate the driver from the car in some numerically quantifiable manner. Other motorsports use brackets, or spec cars, or direct rules manipulation (i.e. restrictors, victory weight, etc) to make things equal, but you never see anything like PAX in other motorsports (at leas tI can't think of an example). I think that speaks volumes towards how impossible the task is. It would be some sort of awesome breakthrough to be able to quantify car performance with enough accuracy to allow pure driver comparison, but without a massive data pool for statistical analysis, no matter how scientific you attempt to be it really is just guesswork validated by personal observation.

Comparison to the theory of gravity is valid. But, Newton's theory has been proven to be wrong. It was replaced by Einstein's relativity theories. Which have also been proven wrong, and have had to be augmented by Quantum Mechanics, which are also incomplete which is why String Theory is en vogue. My point is, it's impossible to prove a scientific theory right, you can only prove them wrong. And because the whole PAX/HAP thing is a very emotional subject with racers, until you can prove HAP is right (which is impossible) you'll never get people behind it.

Granted, I'm exaggerating a bunch with my example (a useful HAP need not be as rigorous as a unified theory of physics :lol: ) but I'm trying to illustrate that attempting to quantify performance in an index is perhaps the wrong approach to the problem in general. Like I mentioned earlier, if we approach the issue as "focusing on driver performance" instead of "leveling the playing field" we may be able to solve this issue in a more acceptable-to-all manner. Instead of attempting to factor out the car leaving the driver, let's focus on the driver. Something like a golf handicap, or victory weight, etc.

What defines a good driver? Id' say being fast consistently, especially across different conditions. So if we can compare one driver's consistency to another's across many events, we should be able to determine who's the better driver regardless of their cars, their classes, even their raw times. I can't even really begin to formulate the system, but as long as it's not attempting to say "this driver should win no matter what car we put him/her in as long as we multiply their time by the number for that car" and is instead saying "this driver in their car demonstrates that they're most consistently getting the lowest out of their runs when compared to all the rest of the drivers/cars" then we've fundamentally changed the PAX paradigm and made it not just about the driver, but about the driver and their equipment, which is a fundamental aspect of motorsports competition.

The first question we have to answer of course is "what makes the 'best' driver the 'best'". That in itself may not be answerable, thus making this whole thing I'm talking about moot.

[vic]

you guys need to get a hobby! maybe i do, my brain hurts just from reading this stuff. i know, i will stick to driving

[jim.gandy]

Vic, you're right. My brain hurts, too.

Scott, I absolutely agree. Some kind of system like in golf or bowling would be great. I'll confess: that's a side goal of this whole PAX/HAP thing. If the region can finally agree that PAX is so bad at this altitude as to be a joke (I firmly believe it's a real screw job for something like half our participants), and if HAP is a hard sell (as it seems to be), then it becomes more apparent it would be neat if we had an "individual handicap" system, like golf. There are several ideas floating around...

Thanks, everybody, for the discussion. :)

[Skyhorse]

I was waiting for the driver grading idea to pop up I have seen it work somewhat successfully in motocross both vintage and modern it works there because amateur motocross is 100% rider it’s not until you get into the pro classes that the bike isn’t way faster than the rider so grading is pretty straight forward if someone runs away from the pack they get bumped. In vintage you have novice, intermediate, and expert and a whole lot of people complaining about sandbaggers. with modern bikes they break it out even more and a whole lot more sniveling about people being in the wrong class. I feel that solo has too many variables to even think about trying to rate drivers. The only way to do it would be to make everyone drive the car from Top Gear at the same time.
Scott Knauf- Professional Novice

["A" Stocker]

How different are the Rick Ruth PAX scores, than the HAP PAX Scores?
If the series ran at sites with way different altitudes a HAP would possibly come into play, but since everyone runs at the same site / same altitude all the time a HAP is not necessary. The Rick Ruth Pax Factor's come from taking results from all over the country, which includes alot of different altitudes (Denver to Florida). In Reno everyone's car is down on power and those same cars pick up power if they come down and run Sacramento (relatively speaking).

[sperry]

How different are the Rick Ruth PAX scores, than the HAP PAX Scores?
If the series ran at sites with way different altitudes a HAP would possibly come into play, but since everyone runs at the same site / same altitude all the time a HAP is not necessary. The Rick Ruth Pax Factor's come from taking results from all over the country, which includes alot of different altitudes (Denver to Florida). In Reno everyone's car is down on power and those same cars pick up power if they come down and run Sacramento (relatively speaking).
Now you've opened the can of worms!

The fundamental issue between PAX and HAP is that because PAX numbers are based on sea-level car performance, and because all cars fundamentally do not lose power in the same ways at altitude (think turbo vs. normally aspirated) PAX is not an adequate factor for Reno. Thus is born Jim's HAP system.

The discussion about whether or not PAX itself is fair is yet a whole 'nuther worm can.

["A" Stocker]

Now you've opened the can of worms!

The fundamental issue between PAX and HAP is that because PAX numbers are based on sea-level car performance, and because all cars fundamentally do not lose power in the same ways at altitude (think turbo vs. normally aspirated) PAX is not an adequate factor for Reno. Thus is born Jim's HAP system.

The discussion about whether or not PAX itself is fair is yet a whole 'nuther worm can.

They are not based on sea level only, they are based on events all over the country from Denver (5,280') to Florida (sea level) and everywhere in between.
So, if you take the same cars from Reno down to Stockton to run Sacramento events, do you think the results would change, I don't a fast car in Reno is going to be a fast car in Stockton (Ray,Kenny,Jay Kelly,Randy and Peggy prove that point).
If all the cars run at 4500', then all the cars run at sea level, the results aren't going to change. I still stand by that IF all the cars run the same series at the same location, the PAX Factors don't need to change: fast cars are fast cars.
In all reality PAX Factors,HAP Factors or Street Tire Factors are thought up because the guy got tired of getting his A** Kicked and he needs a reason to feel good. So he takes a calculator and an arbitrary number he has and through the magic of a few key strokes he is now .3 ahead of the guy, when in reality the only way he beat the guy was with the help of a calculator and not by improving his driving skills or his car

[sperry]

They are not based on sea level only, they are based on events all over the country from Denver (5,280') to Florida (sea level) and everywhere in between.
So, if you take the same cars from Reno down to Stockton to run Sacramento events, do you think the results would change, I don't a fast car in Reno is going to be a fast car in Stockton (Ray,Kenny,Jay Kelly,Randy and Peggy prove that point).
If all the cars run at 4500', then all the cars run at sea level, the results aren't going to change. I still stand by that IF all the cars run the same series at the same location, the PAX Factors don't need to change: fast cars are fast cars.
In all reality PAX Factors,HAP Factors or Street Tire Factors are thought up because the guy got tired of getting his A** Kicked and he needs a reason to feel good. So he takes a calculator and an arbitrary number he has and through the magic of a few key strokes he is now .3 ahead of the guy, when in reality the only way he beat the guy was with the help of a calculator and not by improving his driving skills or his car
You're missing the point:

A Miata at sea level makes say 150 hp. At altitude, it makes say 100 hp. A loss of 33%.
An STi at sea level makes say 300hp. At altitude it makes say 260 hp. A loss of 13%.

So, because the turbo partially counters the effects of altitude vs. all the non-turbo cars it's now a class killer in Reno. It really has nothing to do with PAX. HAP is an attempt to quantify and factor out the altitude disparity. While I don't think HAP is the solution, I do agree there is certainly a disparity between cars that weren't accounted for when the classes were developed based on sea-level performance.

As far as the point of PAX... in that you're dead wrong. It was never a pencil-pusher means of winning. :rolleyes: It was developed as a "Racers Theoretical Performance" to allow cars in different classes to compare times with each other. It's evolved into a sore point because uninformed people that don't understand it spout off about how it's unfair with out understanding why it's unfair. If people understood it better they just might use is as it was intended: as a rough estimate to allow people to judge performance across classes instead of some carved-in-stone means of picking out the best driver.

["A" Stocker]

You're missing the point:

A Miata at sea level makes say 150 hp. At altitude, it makes say 100 hp. A loss of 33%.
An STi at sea level makes say 300hp. At altitude it makes say 260 hp. A loss of 13%.

So, because the turbo partially counters the effects of altitude vs. all the non-turbo cars it's now a class killer in Reno. It really has nothing to do with PAX. HAP is an attempt to quantify and factor out the altitude disparity. While I don't think HAP is the solution, I do agree there is certainly a disparity between cars that weren't accounted for when the classes were developed based on sea-level performance.

As far as the point of PAX... in that you're dead wrong. It was never a pencil-pusher means of winning. :rolleyes: It was developed as a "Racers Theoretical Performance" to allow cars in different classes to compare times with each other. It's evolved into a sore point because uninformed people that don't understand it spout off about how it's unfair with out understanding why it's unfair. If people understood it better they just might use is as it was intended: as a rough estimate to allow people to judge performance across classes instead of some carved-in-stone means of picking out the best driver.

How can you say it is based on sea level performance, when the results from Denver and 40 other places over sea level are used to compute the PAX Factors. Your right cars in different classes (PREPPED THE SAME) to compare times with each other, key being prepped the same or in other words make a guy running in G Stock feel good that given a .5 sec head start he should be able to atleast tie the guy in A Stock he's comparing times with as an example. Yes, I agree if the PAX is used correctly it's a good tool (to an extent) like prepped cars to like prepped cars. Throwing in another factor because the guy decides to run on street tire instead of r-comps like the rest of the class is ridiculous at best--now your making up for lack of prep. Now back to the Subject of HAP:

The class killing Turbo car is still going to be the class killing Turbo car at sea level.

[jim.gandy]

The above exchange between Doug and Scott should be required reading before anyone is allowed to look at or even think about PAX or any other indexing system... :o

Their exchange is a great illustration of just how hard it is to have a dialogue about indexing and altitude. Doug is not alone -- there are lots of people who are resistant to one or both of the following two very basic ideas.

First, altitude plays a big role in autocross performance, and the effect is significantly unequal across classes and across cars within classes.

Second, PAX is heavily biased towards events that take place at much lower altitudes.

I firmly believe that the evidence supports both of those ideas. That's right, I said EVIDENCE, not theory. And when I say evidence, I'm NOT talking about event results, I'm talking about established facts you can find in books.

Anyone can do it. Go to the engineering texts, and look up the tables that present horsepower losses vs. altitude for various induction systems. Go to the PAX website and get the list of events incorporated in the PAX database, then get an atlas and look up the altitudes of those events. Don't take my word for it; convince yourself!

The two basic ideas stated above should be accepted as facts. Until a person can stand on that sliver of common ground, pretty much everything else that has to do with performance indexing will seem like a foreign language.

Sometimes I get the feeling people think that talking about high altitude performance indexing is actually blasphemous -- their reactions are so sharp. That's just my persecution complex kicking in... :)

[sperry]

The above exchange between Doug and Scott should be required reading before anyone is allowed to look at or even think about PAX or any other indexing system... :o

Their exchange is a great illustration of just how hard it is to have a dialogue about indexing and altitude. Doug is not alone -- there are lots of people who are resistant to one or both of the following two very basic ideas.

First, altitude plays a big role in autocross performance, and the effect is significantly unequal across classes and across cars within classes.

Second, PAX is heavily biased towards events that take place at much lower altitudes.

I firmly believe that the evidence supports both of those ideas. That's right, I said EVIDENCE, not theory. And when I say evidence, I'm NOT talking about event results, I'm talking about established facts you can find in books.

Anyone can do it. Go to the engineering texts, and look up the tables that present horsepower losses vs. altitude for various induction systems. Go to the PAX website and get the list of events incorporated in the PAX database, then get an atlas and look up the altitudes of those events. Don't take my word for it; convince yourself!

The two basic ideas stated above should be accepted as facts. Until a person can stand on that sliver of common ground, pretty much everything else that has to do with performance indexing will seem like a foreign language.

Sometimes I get the feeling people think that talking about high altitude performance indexing is actually blasphemous -- their reactions are so sharp. That's just my persecution complex kicking in... :)
Jim, I agree with this 100%. I may be a contrary voice for the most part when it comes to HAP, but I fully agree with your argument about the merits of a HAP system. Altitude does have a real-world and unequal-between-cars effect on horsepower. It's actually the most quantifiable effect of everything we've discussed here.

So while I disagree that HAP can be a quantifiably successful system for "fixing" the altitude problem, I do whole heartedly agree there is an altitude problem. I just think a good solution needs to be based more on driver-to-peer comparison than on attempting to numerically counter altitude disadvantage, specifically to appease the many people that simply don't believe there's even an issue.

[AlexR]

Hey Jim,

yes my first post did imply you were wasting your time (due to my belief of all of the factors being overly complicated, mainly throttle position ) Which was a bit harsh of me, and incorrect.

Its defiinitely not a waste of time. Any disscussion (or proposed system) that brings forward new ideas is very worth while and thank you for your efforts!

I think scotts idea of a different system based upon how many people you beat , or even Victory weight are worth while to pondor over.

Although victory weight may not work out very well in standard daily driver cars ie how to secure safely. Also how much weight would you have to add to the top drivers??

Jim, It may be interesting to compare your times with the folks who come up from Sac and 1 or 2 other drivers willing to do a sacramento event. then using your HAP formulas deduce what time splits those drivers should have down in sacramento.
It would not be enough of a sample to be stastically valuable , But the results may change a few opions ..

I'de be willing to go to a sacrameto event, But my driving is inconsitant and may not be good enough for any value (also barring any conflicts for the Formula RallyX series dates)

[sperry]

The "victory weight" would be just a multiplier against your raw time based on how much you're dominating... not actual lead bolted to the floor. :lol:

[jim.gandy]

Alex, you're 100% right that any results involving an exchange of drivers between high-altitude and low-altitude sites are worth looking at. And, yes, some drivers produce data that's, um, somewhat less reliable than others.:) That's just one of many reasons why it takes a lot more than one instance of HAP appearing to work (or of HAP appearing to be screwy).

Obviously, it would help the evaluation process if Reno Region had more drivers who are entering national-level events, and who have the driving and car prep chops to compete there.

So, why are so few Reno Region drivers doing national-level events? IMHO, this is another interesting topic, one that could be a whole additional forum thread, with blood on the floor and all that stuff...

[Kevin M]

So, why are so few Reno Region drivers doing national-level events? IMHO, this is another interesting topic, one that could be a whole additional forum thread, with blood on the floor and all that stuff...

I can probably sum this one up for you Jim, without spilling a drop! Basically, almost everyone who has ever autocrossed has had fun doing it. A solid minority (I'm thinking less than half, more than... I dunno, 20%?) loves it so much they want to be competitive against their friends. And a good portion of those drivers want to go on and compete against the best and try to win. Solo is fun for everyone; but investing the time, resources and motivation into being highly competitive isn't universally satisfying. So in small regions like ours that for years have prided themselves on being about fun and friendship over produucing top competitors, the scales will always tip towards fun when it comes into conflict with prepping people for Nats. Just my $.02 on it, but I'm reasonably sure I'm close to the mark.

[TracDaz]

If HAP is faulty, and it's developed from PAX with logical educated corrections for high altitude losses, then why do we subscribe to the obviously faulty PAX? Isn't winning your class good enough? Isn't beating that guy from Sacramento in his tricked up Corvette good enough? Does winning PAX, knowing it's inaccurate and essentially biased toward blowers and big cubes at Reno altitudes, mean anything? We spend more time arguing PAX than any other subject. If it was a meaningful gauge there would be no argument. Does it make that much difference to have bragging rights when we all know PAX is established on quasi-applicable data for the Reno area? [I'm not scared because I'm wearing my helmet]

[MikeK]

Isn't beating that guy from Sacramento in his tricked up Corvette good enough?

If only that were possible :mad:

[Jamin]

Hmm. Interesting concept. Running an N/A car in the Utah region for a longish time against forced induction cars in GS and STX, I have to say this is a very interesting concept. Props on recognizing the complexity involved though. A few notes on the tech stuff in the first post?

All FI cars are not created equal - actually, all forms of FI are not, and the math presented does not account for this. Turbo cars lose some cokpressor efficiency but will still make maximum boost at altitude. The turbine will continue to spin faster and faster until maximum boost is reached. It may take a few hundredths of a second longer at 50000 ft, but it will get there. Supercharged cars on the other hand, have a compressor that runs at a static rate in relation to engine speed. Less air in/less air out is accurste in this instance. They may or may not still make full boost at some point in the revs, but they make less boost at every level in relation to RPM until such time as they (if they) reach their maximum. In fact, percentage wise, blowers lose ALMOST as much power as N/A cars.

That makes the HAP concept even harder, lol. Sorry...

Gotta go, more later - I like this discussion! :)

[MikeK]

Turbo cars lose some cokpressor efficiency but will still make maximum boost at altitude.

On my STi I was finding that an ECU map that makes 23 psi at sea level only makes about 20 psi up here in Reno. Also, peak boost is almost 500 rpm later.

I got my tuner to make me a special high alt map which does make the full 23 psi up here, but of course it involved custom tuning. So yes, a turbo car can make full bost at altitude, however on my car a custom high-alt only map was required to do it.

So for cars running in stock classes that can't touch boost profiles, or cars that can't change ECU maps, this isn't strictly true.

[MattR]

My car makes 21 PSi at Sea level, and 17 peak at altitude. Without switching to my altitude map. So that is a huge power loss as Mike said.

[sperry]

Just on the fun side of things, here's what Mike Shield's had to say about tuning for Pike's Peak back in 2005 on our Subaru board:

The problem with altitude is not really a problem until maybe 8-9000 feet with most modern turbo cars, although I would say from 6000 up the effects starting to show. The rally cars can also run JEMS or Pectel or other racing ecu that have provision for anti-lag and other racing tweaks not found on a road car. Yet it uses the same turbo, injectors, in short, a completely stock STI 2 liter engine with a 30mm intake restrictor. The Mass Flow sensor of the Subaru engine is pretty much going to give the same AFR at 15,000 feet that it will give in Death Valley. This is because it measures not the air flow, but the air mass flowing in. So it compensates for relative humidity, temperature and pressure at all times. Of course, how one programs an ECU to deal with that information is another subject!

The altitude issue concerns the very nature of turbocharging. The compressor has a map of flow/pressure ratio (note: not absolute boost, rather boost relative to 1 bar atmospheric) that shows the heat of compressing the air, that being known as inlet temperature in every day language. The ideal sizing of a turbocharger is related to the power expected (a mass flow issue) and the engine displacement. Each compressor has what is called the sweet spot, a largish , but skinny, 45 degree oval where the inlet temperature is as low as possible for the boost levels. We also have to size the compressor so as not to over speed the turbo, more on that in a minute. Anyway, an engine runs up and down the rev range in this lower inlet temperature area if sized properly . Put in technical language, the turbocharger is running at its maximum efficiency . Now you can imagine what just turning up the boost on a motor does. It moves the compressor load outside of the sweet spot and begins to (sometimes quickly) increase the air inlet temperature. A bigger intercooler is not quite the answer, although when running 20+ pounds of boost we need to go to large front mount (no where else to put it!). What is needed is a compressor housing that has its sweet spot better matched to the power, and in this case of a 2 liter displacement, the higher boost being needed to make that extra power for the given displacement. With 91-93 octane fuel and a proper timing and fuel curve we simply do not need a huge intercooler because we just do not take the boost level up that much. This is because we do not boost levels that will cause detonation, unless of course ,one backs the timing way off and dumps loads of fuel into it. That will give a nice reading on the dyno. The car has awful throttle response and tuning hard setup like that will kill a motor over time. For this reason, buying a re-flash based on maximum HP quoted is all to often a bit of a fool's paradise. What we want is a motor tuned for proper ignition and fuel with the boost curve where it comes out against the detonation sensor. This gives huge torque, excellent spool and throttle response, and what ever power number that the motor feels good making on a given day. This is how the Prodrive Stage 3 is setup. 10 years of rally car experience, 6000 units sold and no blow motors.

The problem with 14,000 feet is the air density is 50% that if sea level. The effect is to make the turbocharger work as if it was not making 14 psi, but as if it were trying to make 28 psi at sea level. Besides over speeding the turbine, this is will physically overheat the motor due to too high of an inlet temperature for which no intercooler will correct. So, we have to turn down the boost starting at ~8000 feet as we have reached the limit of the turbo speed and are already way outside the sweet spot. The driver also has to gradually lower the operating limit of the engine from 6000rpm down to 4500 from 8-9000 feet to 14,000 feet . By limiting engine speed, working as an air pump the compressor is now limited to pumping as much pressure RATIO from the thin air as it was pumping from thick air at sea level. We have to remap the engine for these extreme altitudes and very high full throttle duty cycle, only seen at Pike's Peak. The next highest rally is Mexico WRC run at 6000-7000 ft, but the real kicker at extreme altitude is the constant climb.

Pat' Richard (Rocket Rally/Easy Street) and Stieg Bloomqvist (Prodrive, David Sutton Cars, Ltd) were the only Group N (30mm restrictor) cars that had ANY power as they went past me at 13000 feet Saturday. The Rocket Rally crew worked on the ECU mapping Tuesday and even Wednesday during the first stages of the rally to get it right.. Andy, the Prodrive UK engineer for Bloomqvist worked even Friday night tweaking their setup. Andy joked it was the slowest rally car he had ever tuned!

Pat had ten seconds on Stieg as of Saturday morning with the full climb ahead of them. Stieg was his usual smooth as glass self, but Pat's car broke a rear drive axle putting the power down on the very last of the lower tarmac section.

So the problem became that Pat had to try to keep our position by abusing the motor with too high of RPM, using 6200rpm all the way up and outside of any hope for a reasonable inlet temperature. This caused the turbo compressor to pump heat into the engine, which was being taken out through the cylinder walls . Just at the 14,000 foot finish we stuck the pistons as they continued to expand right past their normal racing clearance. Stieg was able to gain 10.5 seconds and just pull off the win. They do say you make your own luck in racing. In this case, Stieg's 30 years of experience got him to the top without breaking anything on the final run after three days of abuse. So much for altitude stories at Pike's Peak.

Regards,
==m==
Mike Shields
SPD Tuning Service
www.spdusa.com

A turbo car certainly doesn't compress the air to the target boost at any altitude... in this extreme it can't get there! But with proper tuning and setup, a turbo car certainly is better at altitude than a supercharged car... though that's nothing a new pulley ratio can't help... and both are a crapload better than N/A.

[Jamin]

I was oversimplifying, lol. And in stock classes, turbo cars can't remap, and blown cars can't run smaller pullies. It's something drag racers ***** about quite a bit - the NHRA altitude correction factor is the same for any FI method, and turbo cars get a big advantage from this in say, Reno or Salt Lake City or Denver.

In any event, I was bringing it up only to point out that imperfect system that PAX is, and as much as I like the HAP concept, here's one more technical wrench to throw in. The current PAX system doesn't account for altitude AT ALL, which is kinda BS - but once you take a step on the slippery slope that is HAP, then people can start in with the further "sub-segmenting" complaining about turbo vs blown, etc.

Back to PAX in general and it's imperfections... Well, that's pretty well documented. The MCS is still in G, the Mazdaspeed Protege in still in D, half of G hasn't been moved to H in response to the clearly DS cars dropped to compensate for their not bumping the MCS up and therefor alienating a bunch of cars that would otherwise be fun to run, and the net result is that if someone doesn't pull out some amazing runs in a new Cobalt SS or BMW 1 series or Audi etc, the GS PAX will likely be higher than DS next year, LMAO. And that's just the DS/Gs debacle, nevermind the other classes that the PAX "gurus" haven't addressed. (I actually hava a side bet running weitha freind on whether or not GS outruns DS at Topeka this year. In the meantime, I tell people I run in "dog stock" - D Or G. :p )

If they can't get THAT right, I don't see HAP "hap"pening anytime soon - though I reiterate that I LOVE the idea.

[RBrown]

Hello Reno SCCA Members!

After reading about HAP (high altitude pax) And thinking it through I was first thinking it was a great idea. But when i sat down to really think it over I started to realize while it’s a noble idea, it would be exceedingly difficult to come up with a factor that would adequately take into account all of the factors that come into play. After more analysis I don't even think Its an issue with in certain classes. how could this be ? read on :

How does attitude change my cars power?

First we need to think about how a car makes power. The power your car makes is from burning gas. Basically your car uses all of the available O2 and burns a large % of the gas sprayed in . (excess fuel is sprayed in for cooling purposes, this extra fuel burns with O2 available in a solid form in your catalytic converter)
So basically the more Air the more power the less air the less power.

Sea level atmospheric pressure is 14.696 PSI (1) and the air pressure at 5,000 feet is about 12.23 PSI (1) so our air pressure is only 82% of normal.
So for naturally aspirating cars you can expect to lose about 18% of your power. What about a super or turbo charged car?

Force air induction vehicles use an air compressor (turbo , or super charger) to add a set amount of PSI. (unlike a Turbo Prop airplane , which adds a varying amount of PSI depending on altitude so that certain air craft run at 15 PSI from 0 feet to 20K or 30K at which point the turbo starts to taper down to lower boost leves )
The Motor on these cars suck in air that is at a higher air pressure, then their naturally aspirating counterparts. For example an Impreza WRX STI has 14.5 psi of boost. So at sea level during peak boost the car runs at 29.2 total PSI! What is the affect of high altitude on the STI? In terms of total PSI lost, its exactly the same, 2.46psi lower, or it will run at a max of 26.7 which is 91.5% of its sea level power.
The Evo 8 & 9 boost around 19 PSI (4) and thus they run at about 92.8% of seal level power. The chevy colbolt uses 12 psi of boost , so it ends up at 90.7 % of its sea level power. A mini cooper S runs at about 10 psi (89% of its sea level power) and so on..

So we could come up with a penalty index for each boost level right? Right , well no the total power generated is not = total power your car can put down. If you take a RWD high HP car (like a corvette) even with racing slicks these awesome cars can Spin their rear tires if the driver tries to accelerate too quickly. Basically any time the driver does not have his throttle over 82% open , he’s not being affected by the loss of horse power, Just when the driver is WOT (wide open throttle) well this is the same for all cars right?

Not so, other cars such as the All Wheel Drive STI can be driven using 100% throttle with out spinning the tires. So depending on course design these 2 cars may battle each other and get the same results as if they were at sea level. Actually If the high HP RWD never used over 82% of his throttle , and the STI drove around at WOT, the high HP RWD car has an advantage at high altitudes !! (Science is often stranger than fiction!) For cars that never can spin their tires, even at sea level (think a Street prepared Miata with Wide racing slicks) The miata will be at a disadvantage when trying to compete in overall PAX versus high horse power cars who rarely can use 100% of their power.

So if someone wanted to correct this , they would need to come up with an attitude factor and then they will have to adjust it for every boost level, also we will have to take into account Drive train (if wheel spin is ever possible ) , and total time spent at WOT. We could do this right and be done? Well no

I’ve used the term “peak boost” quite a few times. that’s because the air compressor has to Spin up to a certain speed (depending upon engine rpm) to give peak boost. Super charged cars have their air compressor connected via a pulley and always create a set amount of PSI per RPM of the motor. A turbo car uses exhaust gases to spin up its air compressor. So anytime you are not on the gas pedal your turbo spools down, and your boost level goes does. And when you press on the gas pedal in a turboed car there is a delay before the turbo is felt at all (this is called Turbo Lag) Depending upon the course lay out a given car may never hit peak boost , or he may be at peak boost for 40% of the course. It really just depends.

Mike K's STI has a Big Turbo on it, some courses he never sees peak boost, he might not even be hitting 15 psi on some courses due to such great lag.

So could there be combinations of course + cars + driver where the NA driver was not affected by the loss of power? Yes actually its possible, think about an overly tight course where a Z06 on streets is never going to be able to go WOT !

Are there courses where a forced induction car is not being assisted by its compressed air , Its possible, but personally think its highly unlike that a forced air induction car ever runs a course at high altitude where the air compressor would not help out, It’s also just as impossible that these cars are driving the entire course at peak boost (unless we go for a 20' long straight course!)

Also to muddy the waters is the black art of LFB a turboed car. WTF is that you ask? if you hold down your gas pedal, but you also press down your brake pedal, the car slows down, but the Turbo spools up , then when you release the brake you start off at a higher boost than if you got off the gas completly during braking. (1, this is probably bad on the car, 2, this usually results with me missing my Apex by about 30 feet as i oooh and aaah that my boost level stayed a few psi higher)

So In my opinion trying to alter PAX factors for altitude is so complicated that even the most meticulous attempt is bound to be very, very inaccurate. While PAX isn’t perfect , there are less variables to take into account then trying to adjust PAX for Cars and Tires, Than comparing altitude and boost levels.

I would conclude HAP has more complexity then PAX.

This leads me to think it will end up more flawed no matter how hard we try.

Alex Rademacher

Sources :

1)http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html (http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html)
2)http://www.caranddriver.com/comparisons/9043/2005-mitsubishi-lancer-evolution-mr-edition-v-2005-subaru-impreza-wrx-sti.html (http://www.caranddriver.com/comparisons/9043/2005-mitsubishi-lancer-evolution-mr-edition-v-2005-subaru-impreza-wrx-sti.html)
3)http://www.theautochannel.com/news/2005/04/12/036407.html (http://www.theautochannel.com/news/2005/04/12/036407.html)
4)http://autos.aol.com/article/power/v2/_a/2005-mitsubishi-evolution-mr/20061030194809990001


Hi Alex,
As a pilot (and autocrosser) this discussion caught my eye. Modern tubocharged street cars use electronic control of the wastegate. The turbocharger is typically sized such that they can maintain sea level design boost pressure up to a certain altitude until they loose regulation. I used to have a Typhoon which maintained sea level absolute manifold pressure to 4000 feet. I'm an SAE member and I did a quick literatue search to see if I could find something on the Evos and WRXs but didn't see anything. My take is at 5,000 foot Stead elevation they are down on power but perhaps not by as much as your calculations would indicate.

[sperry]

Hi Alex,
As a pilot (and autocrosser) this discussion caught my eye. Modern tubocharged street cars use electronic control of the wastegate. The turbocharger is typically sized such that they can maintain sea level design boost pressure up to a certain altitude until they loose regulation. I used to have a Typhoon which maintained sea level absolute manifold pressure to 4000 feet. I'm an SAE member and I did a quick literatue search to see if I could find something on the Evos and WRXs but didn't see anything. My take is at 5,000 foot Stead elevation they are down on power but perhaps not by as much as your calculations would indicate.
Ye old butt-dyno tells me a 300hp STi is probably around 275hp up here. It's not much loss, but enough that when you go down to the Bay Area or something for the weekend, the car puts a bigger smile on your face and you find yourself driving with a little more right-foot down there 'cause the car picks up a bit and it's more fun.

[RBrown]

Ye old butt-dyno tells me a 300hp STi is probably around 275hp up here. It's not much loss, but enough that when you go down to the Bay Area or something for the weekend, the car puts a bigger smile on your face and you find yourself driving with a little more right-foot down there 'cause the car picks up a bit and it's more fun.

That sounds about right. I'm down around 18% on power (600hp down to 500hp) in the BP car. I can definitely give it more throttle exiting at Stead than I can down here. With a carburetor I change 4 jets, two power valves and put in or take out timing going from Sac events to Reno events. Pretty old fashioned. Fuel injection would be nice.

-- Rick

[AlexR]

1) Turbo prop airlines do keep full power to a given altitude ( I know a pilot who owns a twin turbo prop sesna (spelling)) Cars don't do that :(

That sounds about right. I'm down around 18% on power (600hp down to 500hp) in the BP car. I can definitely give it more throttle exiting at Stead than I can down here. With a carburetor I change 4 jets, two power valves and put in or take out timing going from Sac events to Reno events. Pretty old fashioned. Fuel injection would be nice.

-- Rick


glad to hear one of my points backed up by a driver. for all parts of the course that you Can't use 100% Throttle due to tire spin, you are not being affected by the altitude. Which means to make a correct HAP Factor you have to have some Estimate of how long are you really at full throttle. If a course was designed in a manor that a given car could never exceed 50% throttle he wouldn't be going any slower in stead than he would in sacramento.

IE 600 HP Vette in a tight corner going into a slalom probably has the same speed up here as in sacramento.

Hey Rick, Say on sundays course, could you give an guess estimate how much of the course you were driving WOT ?

[RBrown]

1) Turbo prop airlines do keep full power to a given altitude ( I know a pilot who owns a twin turbo prop sesna (spelling)) Cars don't do that :(




glad to hear one of my points backed up by a driver. for all parts of the course that you Can't use 100% Throttle due to tire spin, you are not being affected by the altitude. Which means to make a correct HAP Factor you have to have some Estimate of how long are you really at full throttle. If a course was designed in a manor that a given car could never exceed 50% throttle he wouldn't be going any slower in stead than he would in sacramento.

IE 600 HP Vette in a tight corner going into a slalom probably has the same speed up here as in sacramento.

Hey Rick, Say on sundays course, could you give an guess estimate how much of the course you were driving WOT ?



First the airplane stuff. That's either a Piper Seneca or Cessna such as a T210. They aren't turboprops, they're turbocharged piston engines. Aircooled 6 cylinder 510 cubic inch 2700 rpm deals. For reliability and detonation control, power is limited by limiting boost at lower altitudes, and above a certain altitude you can't maintain 70% power even with the waste gate fully closed so the power tapers off. On a different note, a couple of years ago I saw you guys autocrossing at Stead on a flight to Tahoe so I landed and taxied over.

Ok, car stuff. I wish I had the beacon's out so I can answer for sure since the software will give me statistics on throttle position. I went back and looked at data from Stockton where Sac chapter runs and typically I'm full throttle about 2-3 seconds per minute of course time depending on the course. I'm going to guess that in the 51 second run on Sunday I was full throttle for 5-8 seconds. Next time I'll put out the beacons.
--- Rick

[jim.gandy]

Here is the 2008 High Altitude Performance factor chart. Remember, this is a work in progress -- I reserve the right to make changes at any time. Last year, I changed the factors once during the year, in July.

[jim.gandy]

Attached to this post is the HAP results sheet from Reno Region's Solo Round 1. It's got HAP and PAX side-by-side for convenience. Keep in mind that Ladies and Open entrants are listed together; that's why an individual driver's ranking in PAX may not be the same as other PAX listings you've seen.

[Jamin]

According to that chart, my car runs slower there than an HS car at sea level. I think the "time at WOT" factor is a lot bigger than that chart accounts for - I'm pretty sure that all things/drivers equal, I could run faster up there in my underprepped DS car than an HS car at sea level!

[Kevin M]

Remember that it's all relative Jamin- all cars run slower up here than at sea level, HAP is just intended account for that relative difference.

[nmhansen]

Interesting, I would have moved up one spot with HAP versus PAX. I would have thought it would have gone the other way for me. It looks like only a few people (from a quick glance) moved more than just a few spots.

One thing to note Jim, the De Los Reyes' brothers 00 Subaru Impreza RS is not a forced induction vehicle. Its a naturally aspirated 2.5L 4 cyl.

["A" Stocker]

I can't see by these results where using the HAP over the PAX would be worth the effort. Other than a few people changing places, where did the results between the 2 differ enough.


1 BSP Ken Yeo 89 Chevy Corvette 50.28 1 Ken Yeo 0.858 43.140

2 BSP Ray Miller 89 Chevy Corvette 50.762 2 Ray Miller 0.858 43.554
3 BP Rick Brown 90 Chevy Corvette 51.424 3 Rick Brown 0.866 44.533
4 BSL Debbie Kerswill 04 Mazda RX8 54.306 4 Al Patterson 0.862 45.152
5 ASP Al Patterson 06 Dodge Viper 52.38 5 Debbie Kerswill 0.832 45.183
6 SS Jeff Glorioso 03 Chevy Corvette Z06 53.129 6 Jim Uchytil 0.867 45.244
7 DSP Gilbert De Los Reyes 00 Subaru Impreza RS 53.712 7 Jeff Glorioso 0.852 45.266
8 SS Bob Williamson 06 Chevy Corvette Z06 53.203 8 Gilbert De Los Reyes 0.843 45.279
9 SM2 Jim Uchytil 02 Chevy Corvette Z06 52.185 9 Bob Williamson 0.852 45.329


10 TAS Alex Rademacher 05 Subaru STi 55.658 10 Dean Benz 0.839

[Kevin M]

Nobody said the differences were staggering Doug. But over the course of the season those 1-4 point swings in PAX add up.

["A" Stocker]

Nobody said the differences were staggering Doug. But over the course of the season those 1-4 point swings in PAX add up.

Your going to have that 1-4 point swing using the HAP also, so why try and use a different factor when the one thats already established seems to work. If everyone is down on power, you have no need for another factor. If the turbo/supercharged cars were the only ones down on power at altitude, I could say yea we need to change the factor, but everyone is down on power, the guys really hurting are the N/A guys who have to get the jetting right on their carbs or they have no power, ie: Rick Brown, his car lost 100hp and probably just as much torque, I'm pretty sure none of the turbo/supercharged cars lost that much. Some guys have even stated they just remap their ECU for the altitude change and they don't lose as much. I'm sure those guys would love to go to a HAP, they will just remap back to full power or very close and with alittle help from ye old calculator (HAP Factor), they will proceed to kick the crap out of everybody. The HAP would work if everyone left their cars alone, but with being able to remap the ECU for altitude, the HAP goes out the door.

[jim.gandy]

Compared to PAX, HAP is not going to produce big changes in standings among cars with similar levels of horsepower. Where HAP is most different from PAX is in comparing high-power cars to low-power ones. Check the standings of the H Stock winner, Adam Kovak, a rookie driver in a very stock Civic.

Doug, your understanding of the effects of altitude seem to be very different from mine. As briefly as I can, here's the reasoning I use for HAP...

1) All normally-aspirated (N/A) engines lose something around 18% of their sea-level power at Reno's altitude.

2) Forced-induction engines lose some power, but less than N/A engines.

3) By far the most significant impact of altitude on Solo-course times is when a car is at Wide-Open-Throttle (WOT). (Clarification: I mean accelerating to max capability of the engine, i.e., throttle flat to floor with no wheelspin and no traction control.)

4) The more powerful the car (in relation to weight), the less WOT is used on a Solo course. Therefore, the more powerful the car, the less it is affected by altitude.

Everything HAP does is based on those four ideas. (Incorporating Reno's Street Tire Factor in the chart is just for convenience and has nothing to do with the high-altitude issues.)

If a person can accept those four premises, it becomes easier for them to see the intent of HAP and to understand HAP's methodology. That DOESN'T mean they will become a supporter of HAP.

[Kevin M]

Your going to have that 1-4 point swing using the HAP also, so why try and use a different factor when the one thats already established seems to work.
But it doesn't work perfectly Doug, that's the point of HAP. Everybody up here agrees there's an altitude discrepancy, the arguments just come over attempting to quantify it well enough for everyone to agree on it.
If everyone is down on power, you have no need for another factor.
Everyone is down on power, but not by an equal measure.
If the turbo/supercharged cars were the only ones down on power at altitude, I could say yea we need to change the factor, but everyone is down on power, the guys really hurting are the N/A guys who have to get the jetting right on their carbs or they have no power, ie: Rick Brown, his car lost 100hp and probably just as much torque, I'm pretty sure none of the turbo/supercharged cars lost that much. Some guys have even stated they just remap their ECU for the altitude change and they don't lose as much.
Doug, you do realize that HAP is intended to help the NA cars (small displacement more than large) and not the turbocharged cars right? Corvettes all get a relative advantage in HAP compared to cars like the STi and Evo.

I'm sure those guys would love to go to a HAP, they will just remap back to full power or very close and with alittle help from ye old calculator (HAP Factor), they will proceed to kick the crap out of everybody. The HAP would work if everyone left their cars alone, but with being able to remap the ECU for altitude, the HAP goes out the door.
They already make as much power as possible on their maps; I'm not following what you think they would gain by doing anything else. I don't know if you're noticing or not, but our first event was dominated mostly by NA, race-tire equipped cars. HAP skews results even further in favor of NA cars. And it should.

[Jamin]

Remember that it's all relative Jamin- all cars run slower up here than at sea level, HAP is just intended account for that relative difference.

Exactly. I was just looking at the fact that my car with HAP and without tire factor (I run R's) gets a HAP of .798. I was wrong about the "slower than HS at sea level"; HS PAX is .792 (I was off in my memory). Still - that means according to PAX/HAP, my supercharged DS car is only .006 % faster than an HS car at sea level. I realise that I would be faster than that car at altitude; I'm saying that there's no way I'm running just ahead of what an HS car would at sea level.

Clarification and as it relates to another post above: At Wendover (almost the same altitude you guys deal with), on 245/40/17 RS04's and a not as aggressive as I'd like facotry Quaife LSD, I spent 80% of the course trying to modulate wheelspin. And that was on a reletively open, high speed course. At sea level, I would also be limiting wheelspin, just doing it with still less throttle to obtain the same "controlled spinning". Thus, I'd probably run VERY close to the same time - if not the same or better - at altitude than I would at sea level. The only places I'm losing time is in the long straight WOT sections - which shouldn't be very common in SOLO II. An NA car would have a more exagerrated difference, but really - how often can you lay the throttle all the way down, even in a Civic/Miata/etc on an autocross course?

I think HAP is EXTREMELY accurate - moreso than the standard NHRA factor certainly - for 1/4 mile times, where you're at WOT (almost) the entire time. If you have a car that's at WOT (max power vs traction) the majority of the course, than A.) you have a very open SOLO II course, and B.) a very underpowered car with a lot of tire, LOL.

Sum it up: I think that that chart overstates the effects by as much as 80%. Not that the person creating it hasn't sone homework - WOW is that not the case! - but the more I consider this/apply it in "practice" in my head, the more the throttle position comes into play. An accurate system for HAP in SOLO II would be to measure the percentage of the course that's at WOT in a class example NA car, and multiply the existing HAP factor by that percentage. i.e., if the HAP factor as is is .100 off regular pax, and you measure average throttle position over a season of SOLO courses at WOT 20% of the time, the HAP factor should be .020. The FI cars would do the same - with even smaller differences.

[jim.gandy]

Jamin, IMO you're missing a critical point...

Both PAX and HAP "rank" against A Mod (factor 1.000) -- but even an A Mod car is going to slower by some amount at high altitude. Therefore, you can't directly compare an individual PAX factor with an individual HAP factor and draw the kind of conclusions you did about your high-altitude performance against some hypothetical H Stock car at sea level.

And, since you brought it up ("how often can you lay the throttle down... in a Civic/Miata..."), two weeks ago at Stead we had a rather open course. If you come to Hawthorne you'll see a REALLY open course. I drive an E Stock Miata. At Stead two weeks ago, on a 60-second course, I'm going to tell you I had the throttle mashed to the floor (no wheelspin, no traction control) for at least 35 seconds. I would love to have the ability to capture that data -- it would be important to this whole topic.

[Cody]

*subscribes*

I have to say, this thread has been the most interesting and educational thread I've read in a long time. I was immediately in agreement with Alex when I read his post, and then I flip flopped slowly over the course of reading Jim's posts. Jim, you're doing the Lords work. Now knock it off! :P

I think in a perfect world HAP would look at what National level drivers put down at altitude, and rely only on that data. To me, that seems like the only clean data which may or may not be available, and we'd need a lot of it. Everything else is simply assumption or data skewed by a few of us hamfisted drivers who don't mod to our classes full potential and don't drive to our car's full potential.

[Jamin]

Jamin, IMO you're missing a critical point...

Both PAX and HAP "rank" against A Mod (factor 1.000) -- but even an A Mod car is going to slower by some amount at high altitude. Therefore, you can't directly compare an individual PAX factor with an individual HAP factor and draw the kind of conclusions you did about your high-altitude performance against some hypothetical H Stock car at sea level.

And, since you brought it up ("how often can you lay the throttle down... in a Civic/Miata..."), two weeks ago at Stead we had a rather open course. If you come to Hawthorne you'll see a REALLY open course. I drive an E Stock Miata. At Stead two weeks ago, on a 60-second course, I'm going to tell you I had the throttle mashed to the floor (no wheelspin, no traction control) for at least 35 seconds. I would love to have the ability to capture that data -- it would be important to this whole topic.

I understand precisely how PAX works, with A-mod as the 1.000 & etc. More likely, I'm not being clear in my statement (often the case - it's why I talk so much, lol). In the example I made in my last post (strictly "out of thin air", but as an exapmle), the current HAP would give teh A-mod car a HAP of .900, and my point is that it should get a HAP number of .980, reflecting that .020% difference in time lost while at WOT rather than the time lost due to power across the board.

Wendover and Pocatello have seen to it that wide open courses are well known to me. I'd love to make it up there for a few events if/when time and $$ allow. I'm trying like hell to make Hawthorn, it's 50/50 right now as my GF's been out of work for a while and just started a new job. My income comes and goes (her/my salaries pay the bills, but my racing and any other "extras" are dependant on my bonus/commission checks), and lack of her income for a month means the racing budget suddenly and unexpectedly dropped to about zero real quick. :(

Anyway - on topic again - Cody is right on the money, lol. My thoughts have swung around a bit too, this is fun. I think that data would be awesome, and IMHO abslutely necessay to make HAP accurate.

[AlexR]

I concur with cody and Jamin about looking at national level data.

I have not dug around yet, but does anyone know off the top of their head if the national tour has data on the web about which driver in what car/class had what time and at what site, IE we could look at how the same driver in his HS car was versus the same driver in his AM car at a n LA Race, and then see how far they are apart in pax In Denver ?

[dknv]

I have not dug around yet, but does anyone know off the top of their head if the national tour has data on the web about which driver in what car/class had what time and at what site, IE we could look at how the same driver in his HS car was versus the same driver in his AM car at a n LA Race, and then see how far they are apart in pax In Denver ?National tours have online results, by location. So, there is a separate results link for the Dixie Tour and the San Diego Tour and the Ft. Worth Tour. That said, the problem with looking at data like this, is that you have to have a more intimate knowledge of other factors. You would want to know whether the surfaces were similar, whether the courses were similar enough such that there could be a comparison, especially between classes and types of cars; you would want to make sure you knew what kind of tires each driver was on, because that sometimes changes from event to event. Sometimes drivers are in different cars from event to event. (I know some mini drivers who ran different cars depending on which coast they were at; having stored one car in the East coast region, and one car in the midwest.) The theory is good if nothing else changed, but more times than not there is something different, besides the elevation.

[S2kreno]

There seem to be 2 schools of thought here. It's like stock pickers. One group is into "fundamental" analysis, which is looking at the company's financials, P/E ratios, etc., and the other likes 'technical" analysis which pretty much tries to extrapolate future performance from past data trends. So, our fundamental people would like to put cars of all kinds into labs, drop the pressures to represent various altitudes, run different courses to represent varying degrees of WOT time etc. and then formulate some sort of rule from this to apply to all cars in all situations. Probably not feasible. The other school of thought involves analyzing the data already available from real world racing and coming up with some sort of compromise that won't make everyone happy but might be more "fair" than what we already have. Trying to get it exactly right in all situations will just break our heads and piss us off. So we already know which cars are more high-altitude friendly than others (Scooby-Dos and 'Vettes) and if it's that important to us then we can just buy those cars. And if we don't have those cars then we can just say we don't give a crap about PAX...

[jim.gandy]

Gina's comments open up another facet of this topic that hasn't yet been aired.

She says drivers of cars that don't have a fair chance in PAX at this altitude can "just say we don't give a crap about PAX."

There's more to it.

Some drivers are in cars that, even when prepped to their class limits, still have absolutely no chance at PAX because of altitude. Those "victims of PAX discrimination" are still paying for the PAX trophies.

And, whether you like it or not, PAX still determines who is Reno Region's "Queen and King of Solo." In ancient days (like maybe seven years ago), Reno had "Driver of the Year" awards that were voted on by the board of directors. The board got tired of the responsibility, and the Open and Ladies PAX awards stepped into the gap. Every driver had a shot at Driver of the Year (just win your class, for a start). No so for PAX.

These things are not right, they offend my sense of fair play, and that's why I'm trying to do something about it. Creating a replacement system for PAX is one approach, and that's the one I'm working on. But there are other approaches we could take...

[Kevin M]

Jim, I disagree. Vince Russell has proven that a stock motor Miata can take top PAX at altitude on a regular basis. Further, I would argue that any car that gets within spitting distance of winning PAX is capable of doing so, even if nobody has actually done it yet.

[Dean]

There will always be uncompetitive cars even at their maximum preparation and regardless of driver. That is a basic classing problem. There are n classes and N*100 to N*1000 or so car brands/models/option levels. the majority of those configurations will not be competitive in class much less in PAX or HAP.

This is as true of NA Miatas as it is of FI Subarus.

[Kevin M]

In addition to the CSP example, let's remember that right now PAX is being dominated here by two excellent drivers in a car that is both disadvantaged in class at altitude, and has been dethroned at Nationals. They're winning PAX in a car that shouldn't be capable of it in a field full of top-prepped cars.

[jim.gandy]

Kevin, I appreciate your reasoning, but I question your facts. I watch very carefully the results of Vince Russell and other similar drivers. Without digging through several years' worth of data, let me say I don't remember Vince taking first in PAX here, certainly not "on a regular basis." He may be competitive here in PAX, but against what competition? To answer that, you have to attempt an honest appraisal of our usual PAX winners. That's not easy, because most of them haven't been to Topeka in awhile. Vince has, and we can make certain inferences about his level of competitiveness from his and his co-driver's Topeka results in recent years.

Anyway, just as an example, Vince came up and ran with us at Stead August 4th last year. He cleaned CSP's clock, of course. In PAX, he finished 7th, 1.2 seconds behind winner John Burns. At Topeka a month later, Burns finished 15th out of 26 in F125. Vince spoiled the data by coning like crazy on his way to 25th in CSP, but an SFR driver Vince regularly runs well against finished 5th in CSP. The way I see it, here's a case of a nationally-competitive driver (Vince) coming to Reno and getting beaten in PAX rather soundly by a not-yet-nationally-competitive driver (John). And why did that happen? Again, the way I see it, it's because of altitude effects.

Yes, there's a lot more to it -- weather, surface, course, driver's state of mind, and so on ad nauseum. And one example proves nothing. But I believe that the few facts we can dig up don't support your view that Vince Russell's CSP Miata is a constant threat to take top PAX every time he comes to Reno Region events.

If I'm wrong or have misunderstood what you said, please set me straight.

[sperry]

I firmly believe that the level of competition in Reno isn't high enough that PAX and/or altitude exclude anyone. IMO, any well prepped car in any class is capable of an overall PAX win as long as the driver is good enough.

If Reno had 4 or 5 current National Champions that ran here every weekend, I might change my mind. But currently we've got a few pretty damn good drivers, and a bunch of decent ones, but no one that's a world beater let alone a group of drivers so good that these sorts of issues prevent them from winning.

PAX unfairness and the altitude effect are real issues (and street tire fairness for that matter), but they're not bigger than the simply lack of regional talent. We're just too small a region for there to be competition so stiff those issues are truly keeping people from winning. Car prep and driver skill are still bigger factors.

No offense intended to any region members that disagree with my assessment of local skill.

[Kevin M]

If I'm wrong or have misunderstood what you said, please set me straight.

I guess Scott got to my point a little less obliquely. Ken and Ray are utterly dominating PAX up here (except for the occasional outburst by a kart) and they are doing it in a car that has been surpassed at nationals and is losing more total power to altitude than any car here outside of Prepared/Modified. I don't think that anyone who isn't beating a beatable opponent can whine about unfairness before doing their part to take the top spots- select the right car, buy the right parts, make the right setup, and perfect his or her own skills. Anyone lacking anything in any of those areas has no business complaining about not winning.

[jim.gandy]

Kevin, you say, "they (Miller & Yeo) are doing it in a car that... is losing more total power to altitude than any car here outside of Prepared/Modified." I ask, what's that got to do with it?

Over the last week or so, the concept of Wide Open Throttle (while "hooked up" and with no traction control) has been extensively discussed in this forum. Basically, if a car isn't at WOT, it isn't suffering any significant altitude-created power loss. And the more WOT a car uses on course, the more altitude is hurting that car.

The Miller/Yeo Vette uses only a small amount of WOT here, even on our fast courses. You can tell that just by listening to it. Also check what Rick Brown said in this forum about the amount of WOT he used in his BP Vette at Round 1. I claim it's a provable fact that a car like the Miller/Yeo Vette loses far less time on our autocross courses due to altitude than does a car like, say, the Olofson Cavalier, even though BOTH of those cars have a loss of approx. 18% of their maximum horsepower compared to sea level conditions, which means, yes, the Miller/Yeo car loses more horsepower. But it loses far less time, which is the critical point.

You seem to be saying that until a person ponies up for a killer car and has perfect skills, AND THEN GETS BEAT, you won't listen to any claims of unfairness in PAX. That's just plain wrong, in my opinion. But, I don't expect everybody to see it exactly the same way I do.

[sperry]

You seem to be saying that until a person ponies up for a killer car and has perfect skills, AND THEN GETS BEAT, you won't listen to any claims of unfairness in PAX. That's just plain wrong, in my opinion. But, I don't expect everybody to see it exactly the same way I do.

His point, and mine in my previous post, were that until someone with a well prepped car and superior skills gets beat, the PAX unfairness is moot. Plain wrong or not, I think the results show that the best drivers are in fact winning in this region regardless of the street tire modifier, the PAX unfairness, the altitude issue, etc.

Basically, we're all arguing about the margin of victory here. The guys winning PAX are doing so by like 2 PAX seconds per 60 over the folks that are supposedly losing because of the altitude. Perhaps we can hash this out and change the rules so they're only getting beat by 1.8s, but is there any real difference? Until those disadvantaged drivers are tenths out of winning, this discussion is purely academic from a practical standpoint.

[Jamin]

That's one very excellent and succinct point, no two ways about it.

[Kevin M]

Yeah, Scott had it. Basically, until someone wins PAX with a maxed-out class-topping car with dominant driving performances AND has a significant edge in PAX over someone else who had a maxed-out, class-topping car driven perfectly with a disadvantage from altitude... it's just bench racing from sore losers.

[jim.gandy]

Well, what can I say. Now you imply I have no right to work on this issue.

Until a pipsqueak car (fully prepared) has a fair chance of winning, how can you expect anybody to sink the required resources into it? Would they do it just to prove you wrong? That's not how the world works. If you see an injustice, work to correct it. And you don't have to be one of the people directly injured in order to have a -- dare I say it -- moral right to try to correct the wrong. In lawsuits, maybe you need "standing," but not so in politics, sports or any other arena.

PAX unfairness is not moot, whether it's for a trophy position or for 50th place. Scott, I'm sure you read some of the posts on the Adam Kovac/missing a run issue. Apparently, lots of people ARE concerned about whether they finish 30th or 25th in PAX.

[Kevin M]

Until a pipsqueak car (fully prepared) has a fair chance of winning, how can you expect anybody to sink the required resources into it?

Actually, I think I would have a chance of winning locally if I were to
A: get a handful of class-legal mods I haven't yet, namely lightweight flywheel, upgraded clutch, rear disc brakes (UD/BD) full header-back exhaust, intake manifold port/polish, TB spacers, bigger swaybars and a few urethane bushings. If I'm still in FSP next year, I will have all of these things.
B: Go to race tires. I am not saying that the street tire factor is or isn't fair- I just can't get 275/35R15 street tires in any flavor, let alone the 2 or 3 that are winning nationally.
C: Become a top-flight driver who can put down 1 flawless run out of 3 on average.

I firmly believe, based on calculating my required winning times from those of our frist 3 top PAX times this year, that my car COULD win PAX if I did all those things. If I did them, and missed a PAX championship by an average of a couple tenths, I would still assume the difference was driver skill and not the fact that I'm not in a Corvette, especially since it's so much easier to drive a low-powered AWD car than a modified Corvette, or a Kart for that matter. And if I did decide I deserved to win, I'd probably blame the PAX factor itself, not the altitude disparity. That's just how I see it Jim. So I guess it's not that I think you have no "right" to speak up about HAP. I just think it's not stopping anybody from winning that deserves it yet. Not stopping me from finishing higher than 19th like I did on Sunday either.

[Kevin M]

In engineering terms of effect on raw times, driver skill is a first order force, car/mods a second order force, and HAP/PAX a third order force.

[Dean]

I placed in the top 10, or was it 15, in season PAX in an under prepared basically NO MODS bone stock CS Miata 2 years ago.

I think that is what Scott and Kevin are talking about.

Everyone knows what the rules are and makes their own choices on how to prepare their car and how much seat time to get. The only thing left is innate skill. Attempting to make rules that compensate for any of these beyond what National has already done for the first of the three is nearly impossible and probably not a productive use of time without a lot of statistically significant data.

You have every right to work on this, and it is an interesting intellectual discussion, but don't think HAP as a modifier will be accepted any better than the T factor is. :)

[Kevin M]

IIRC, you were 9th or 10th Dean. And the weekend I drove that car at Squaw, I was 16th or something like that.

[sperry]

Well, what can I say. Now you imply I have no right to work on this issue.

Until a pipsqueak car (fully prepared) has a fair chance of winning, how can you expect anybody to sink the required resources into it? Would they do it just to prove you wrong? That's not how the world works. If you see an injustice, work to correct it. And you don't have to be one of the people directly injured in order to have a -- dare I say it -- moral right to try to correct the wrong. In lawsuits, maybe you need "standing," but not so in politics, sports or any other arena.

PAX unfairness is not moot, whether it's for a trophy position or for 50th place. Scott, I'm sure you read some of the posts on the Adam Kovac/missing a run issue. Apparently, lots of people ARE concerned about whether they finish 30th or 25th in PAX.
I'm not saying that we should abandon work on a better system. I'm just saying no one is really getting the shaft in this region because of the issues.

Not to be an ass about it, but if you're 30th in PAX and want to be 25th, just drive better. It's not the altitude, or the PAX factor, or the tires that are the primary cause of being 30th. Anyone in this region can place higher just be improving their driving skill... no one here is perfect.

Until the people complaining are driving at exceptionally high skill levels, suggesting that PAX unfairness is holding them back is more or less just whining than it is voicing of legitimate concerns, unless we're talking about this from an academic perspective. And I've got no problem discussing this from a theoretical standpoint, but I disagree that any action taken as the outcome of the discussion will have any real tangible effect on the results when compared to simple improvement of driver skill.

[jim.gandy]

Attached are the HAP results for Round 1 (with corrected standings for the De Los Reyes brothers), Round 2 and Round 3. As usual, the corresponding PAX standings are included for your convenience. Remember that these listings combine Open and Ladies into one ranking.

[Kevin M]

Jim, again you definitely deserve praise for your efforts. This whole discussion centers around disputes over data and conclusions generated solely by you and for that you deserve recognition. I appreciate your efforts.

That said, HAP is broken. My class-disadvantaged, low displacement, non-FI, low powered car lost spots in HAP vs. PAX. :lol:

[sperry]

Attached are the HAP results for Round 1 (with corrected standings for the De Los Reyes brothers), Round 2 and Round 3. As usual, the corresponding PAX standings are included for your convenience. Remember that these listings combine Open and Ladies into one ranking.
Just glancing at the results, I'm confused as to how Dean and Alex switch spots between HAP and PAX when they're driving the same car? Are the HAP factors not using the national PAX factors as a base?

[Kevin M]

Just glancing at the results, I'm confused as to how Dean and Alex switch spots between HAP and PAX when they're driving the same car? Are the HAP factors not using the national PAX factors as a base?

SP/SM FI cars are less affected by altitude because they can increase boost to partially compensate. So AS gets a better HAP than BSP/SM relative to PAX.

[sperry]

SP/SM FI cars are less affected by altitude because they can increase boost to partially compensate. So AS gets a better HAP than BSP/SM relative to PAX.
Isn't Alex in SP and Dean in SM?

Edit: Guess not! I thought Alex was running in SP for some reason.

[Kevin M]

He was in STU last year (or 2006?) due to the intake he had.

[82AS]

Jim:
Tell me how you arrive at hap .832 from a pax of .842 for an A stock corvette. Just curious.

[jim.gandy]

Kevin, Scott, Randy, et.al.:

I'll try to answer your posts tomorrow. I'm a bit burned out right now, but I'm glad you all are taking interest and looking at the results. Thanks. I definitely appreciate feedback on the results.

Meanwhile, this message is for Scott...

Scott, I confess your 3:39 pm post got under my skin. I wrote a response -- then I thought better of it and deleted it.

I'll just say I disagree with most of what you said, and I think some of what you said is actually kind of insulting. I'm pretty sure you didn't mean it to be insulting.

It may be hard to see, but contained in your post is the heart of the matter, IMHO. One of the central reasons I'm working on this issue is right there, and the other reasons are pretty much all related to it.

[nmhansen]

The HAP factors are chosen by asking three additional question about the car being driven.

1) Do you have Forced Induction?
2) Is your Car listed in the "In-class disparity list" (yes means your car is at a disadvantage due to differences exemplified at altitude)
3) Is your car eligible for the Street Tire Handicap.

Then its combined with PAX to create HAP

The grid can be found from one of Jim's older posts:

http://www.renoscca.org/forums/attachment.php?attachmentid=12&d=1208460430

The In-Class Disparity List is as follows (again, pulled from the above link):
SS Elise ('05+); Boxster S ('05+)
AS S2000 (all); 911 non-turbo ('95-'98); Boxster (all)
DS C320; Eclipse ('06+); Maxima ('04+)
ASP All Lotus except turbos and Esprit V-8; all Porsche non-turbo
BSP 280ZX non-turbo; 350Z; S2000; RX-8

[sperry]

Kevin, Scott, Randy, et.al.:

I'll try to answer your posts tomorrow. I'm a bit burned out right now, but I'm glad you all are taking interest and looking at the results. Thanks. I definitely appreciate feedback on the results.

Meanwhile, this message is for Scott...

Scott, I confess your 3:39 pm post got under my skin. I wrote a response -- then I thought better of it and deleted it.

I'll just say I disagree with most of what you said, and I think some of what you said is actually kind of insulting. I'm pretty sure you didn't mean it to be insulting.

It may be hard to see, but contained in your post is the heart of the matter, IMHO. One of the central reasons I'm working on this issue is right there, and the other reasons are pretty much all related to it.
Of course my intent is not to be insulting. Perhaps I was being a bit brash in my post. My apologies for offending you Jim.

My point is that with all the discussion over PAX and altitude unfairness (that I will readily agree are real and tangible issues), we have to have a bit of a reality check regarding how much these inequalities really matter in the grand scheme of the results.

When people complain that PAX isn't a fair system for picking "the best driver", I just want to point out that despite the unfairness in the system, the best drivers are still in fact winning PAX. And I think that even with rules that favor some cars over others at our altitude, driver skill is still a much bigger factor in the results than the unfair rules are, and will continue to be as long as the region has such disparity between drivers' skill.

Again, this isn't to say we shouldn't strive to correct the injustice in the system, it's just to point out that the injustice isn't dramatically affecting the usefulness of our results for figuring out who the best drivers are. They're still right there at the top of the list, and they're there primarily because of driver skill, not because of the rules.

If we had people knocking at the top-PAX door but not winning because they're in disadvantaged cars/classes, I'd change my tune, but I don't believe that cars are losing 2+ seconds per 60 because of the altitude, and the people winning PAX are doing so by that much of a margin. Even Jim's HAP results still have PAX dominated by the same drivers in the same cars. To me, that's a pretty good indication that as a region we've got lots of room for improvement outside of the issues with the rules.

[sperry]

The HAP factors are chosen by asking three additional question about the car being driven.

1) Do you have Forced Induction?
2) Is your Car listed in the "In-class disparity list" (yes means your car is at a disadvantage due to differences exemplified at altitude)
3) Is your car eligible for the Street Tire Handicap.

Then its combined with PAX to create HAP

The grid can be found from one of Jim's older posts:

http://www.renoscca.org/forums/attachment.php?attachmentid=12&d=1208460430

The In-Class Disparity List is as follows (again, pulled from the above link):
SS Elise ('05+); Boxster S ('05+)
AS S2000 (all); 911 non-turbo ('95-'98); Boxster (all)
DS C320; Eclipse ('06+); Maxima ('04+)
ASP All Lotus except turbos and Esprit V-8; all Porsche non-turbo
BSP 280ZX non-turbo; 350Z; S2000; RX-8
There's got to be more than that, or the Alex/Dean switch wouldn't have happened between HAP and PAX. Both their cars are y-n-y in HAP, so they both attract the same modifiers, yet Alex moved ahead of Dean somehow because he's in TAS and Dean's in TSM.

I'm not disagreeing with the factors (Kevin's explanation that SM should be less altitude affected because of additional boost is right on), just pointing out that Jim must be modifying the base PAX values as well at some point in the process of creating the HAP factors.

[nmhansen]

Just doing a little numerical analysis here...

Dean's factor went down by .004 (from .839 to .835) or his PAX factor was multiplied by .995


Alex's factor went down by .007 (from .821 to .814) or his PAX factor was multiplied by .991

Looks like you are right. The HAP seems to favor stock cars. Maybe its like Kevin said, stock FI cars versus SM FI cars might have something to do with it (which isn't explicitly listed, but sort of implicitly makes sense).

[MPREZIV]

The HAP factors are chosen by asking three additional question about the car being driven.

1) Do you have Forced Induction?
2) Is your Car listed in the "In-class disparity list" (yes means your car is at a disadvantage due to differences exemplified at altitude)
3) Is your car eligible for the Street Tire Handicap.

Then its combined with PAX to create HAP


I didn't know what the "3 additional factors" were until Nick's post above, and was wondering how my little N/A 4cyl car got SCREWED outta up to 4 places in the HAP spreadsheets that were posted. Then I noticed that my car was listed as "Forced Induction" AND "Not disadvantaged by altitude".

HAP needs accurate information before it's implemented...

[Cody]

It'll be interesting to see how far up you get moved Cory.

I HAPed (doesn't roll off the tongue :p) from 16th to 17th on Sunday.

Edit:

I see Nick, also in ESP, got dropped 3 spots.

[nmhansen]

Another correction:

Justian Vivian's 08 WRX is Forced Induction.

[Cody]

...

[Kevin M]

Kevin, Scott, Randy, et.al.:

I'll try to answer your posts tomorrow. I'm a bit burned out right now, but I'm glad you all are taking interest and looking at the results. Thanks. I definitely appreciate feedback on the results.

I looked again and I made a mistake reading the results- I forgot you added ladies into open, and I actually gained spots in HAP vs. PAX.

[82AS]

The HAP factors are chosen by asking three additional question about the car being driven.

1) Do you have Forced Induction?
2) Is your Car listed in the "In-class disparity list" (yes means your car is at a disadvantage due to differences exemplified at altitude)
3) Is your car eligible for the Street Tire Handicap.

Then its combined with PAX to create HAP

The grid can be found from one of Jim's older posts:

http://www.renoscca.org/forums/attachment.php?attachmentid=12&d=1208460430

The In-Class Disparity List is as follows (again, pulled from the above link):
SS Elise ('05+); Boxster S ('05+)
AS S2000 (all); 911 non-turbo ('95-'98); Boxster (all)
DS C320; Eclipse ('06+); Maxima ('04+)
ASP All Lotus except turbos and Esprit V-8; all Porsche non-turbo
BSP 280ZX non-turbo; 350Z; S2000; RX-8

Nick:
I noticed the Disparity list and that is my point. If you look at last years results in AS at the nationals the S2000 won the class. My Vet does not suffer any less at this altitude over any of the other cars listed, however I get excluded for some reason and I just wondered why. Just trying to understand the HAP math etc.

[Kevin M]

Nick:
I noticed the Disparity list and that is my point. If you look at last years results in AS at the nationals the S2000 won the class. My Vet does not suffer any less at this altitude over any of the other cars listed, however I get excluded for some reason and I just wondered why. Just trying to understand the HAP math etc.

Greater displacement engines suffer less than smaller ones, especially the high-strung ones that need a zillion revs to make torque. It's not that your car doesn't lose power up here, it's that relative to other NA engines, it suffers less. Comparing to FI is another matter.

[jim.gandy]

Everyone,

Seems like some people are gaining an pretty good understanding of how HAP works. I appreciate that very much.

Also very greatly appreciated are the posts that tell me when I've goofed answering the three HAP questions for a particular car. I find it especially easy to make mistakes with the Subies -- I don't yet have the knack for knowing which are turbo'd. I confess, I'm just guessing about the Rochefort Audi, too.

I will always correct those errors. Please be patient for a few days so maybe I can get them all corrected at once, then there'll be a new post.

[Kevin M]

Chris Rochefort's Audi is indeed FI.

For what it's worth Jim, such spirited debate wouldn't happen without merit on both sides. If you really were just a nutjob with a vendetta, nobody would take you serious enough to put effort into such lengthy rebuttals. ;)

[Kevin M]

Perhaps a data collection thread for us to contribute opinions and info for you to asimilate into HAP would be helpful?

[jim.gandy]

Scott, Kevin, et al...

Can I ask to be excused from the "philosophical" part of this debate, at least for a while? We've been doing this for weeks, and I think most of the major points on either side have already shown up.

Of course, if something new gets posted, I'll try to weigh in.

From my point of view, it would be great if people would just let HAP do its thing, offer suggestions/feedback, and hold off on the debate about whether HAP should or should not go into actual use. That would be a good off-season topic.

As I've always said, HAP is a "work in progress." A prototype undergoing testing, if you will. I hope people find it interesting, but I also hope people don't take it TOO seriously.

Remember, PAX was probably a hard sell in its first years, too.

[Kevin M]

I'll excuse you from defending yourself here again if you'll respond to me in the course design thread. :p

[nmhansen]

Nick:
I noticed the Disparity list and that is my point. If you look at last years results in AS at the nationals the S2000 won the class. My Vet does not suffer any less at this altitude over any of the other cars listed, however I get excluded for some reason and I just wondered why. Just trying to understand the HAP math etc.

I agree. The disparity list seems to be the most subjective piece of the whole thing, and I'm not entirely sold on it yet.

I don't know if I see a good reason yet for HAP over PAX. I see myself go up, I see myself go down, and I can't seem to see any good reason why. But, I guess I'm willing to look at it for the season (and that's probably a win in Jim's book for now).

[jim.gandy]

Randy,

You've asked specific questions about how HAP treats A Stock Corvettes. Boiled down, I think you would like to see how your HAP factor (for AS/n/n/n, which is 0.832) was arrived at, and you also want to know why the AS S2000 gets the in-class disparity handicap and your Corvette doesn't.

It's very hard to explain in a forum post. I've spent damn near an hour so far, writing and deleting, and I don't think I can do it. One more try: I think you already know that HAP starts with PAX, then applies mathematic formulas to create the factors that go with the various combinations of answers to the three HAP questions. As I've stated, the formulas are consistent across all the classes, with only a couple of exceptions. As I've also stated, the formulas are constructed to produce different amounts of changes across the fast/slow spectrum of classes. The formulas, especially the basic PAX to HAP conversion, are more complicated than, say, the Street Tire Factor, which is just a simple number.

A person would have to understand the various formulas before they could say they know how their own HAP factor came into being. Only partly in jest, I'll make this offer: I'll teach you everything there is to know about HAP when you can show me how your PAX factor is arrived at. Doesn't that sound fair?

As to the In-Class Disparity List, Kevin explained it pretty well. A Stock is really a zoo of different cars (exactly the way it should be). At the Nationals, the top ten were three S2000s, two Solstices, two Vettes, an STi and two Boxsters. That's a great mix at low altitude, but up here it goes all wacky. Compared to the Vettes, HAP penalizes the Solstices, STis and Boxsters for having forced induction AND then gives the S2000s and the Boxsters some help via the In-Class Disparity.

As it says on the HAP factor sheet, you should contact me about what's on or off the In-Class Disparity List. In a perfect world, there would be solid science behind the list, but for now, it's just me doing what I think works. It's the least-solid part of HAP, I admit. As to future changes to the list, I'll consider anything, but I won't start from scratch -- you gotta give me facts and reasoning. You do the research, I'll draw the conclusions, not the other way around.

[jim.gandy]

I'm looking for help on two things...

Can anybody think of a good name or acronym we can use for "wide-open throttle with drive wheels not slipping and no traction control?"

Anybody have any ideas about how to build a device that would be transferable easily from car to car and would display and/or record the total amount of time during a run that the throttle was pressed to the floor?

These would be a big help in understanding things like altitude effects, course design and even tire choices.

[Cody]

WOT-NS (Wide Open Throttle-No Slip). Traction Control prevents WOT at times, even if you're "flooring-it" so that part goes without including it in the acronym, IMO.

[sperry]

Call it TAMA: "Time At Maximum Acceleration", or just AMA.

And a simple momentary push-button switch attached to a tiny C-clamp that could be attached directly to the gas pedal as input to a simple timer would work. While the pedal is on the floor the switch is down and the timer counts up. Put a button on the timer to reset back to zero. Then figure out the TAMA percentage by comparing the timer after a run with the run time from T&S.

[MikeK]

Can anybody think of a good name or acronym we can use for "wide-open throttle with drive wheels not slipping and no traction control?"

"AWD"

[Kevin M]

I'm looking for help on two things...

Can anybody think of a good name or acronym we can use for "wide-open throttle with drive wheels not slipping and no traction control?"

Anybody have any ideas about how to build a device that would be transferable easily from car to car and would display and/or record the total amount of time during a run that the throttle was pressed to the floor?

These would be a big help in understanding things like altitude effects, course design and even tire choices.

An OBD-II datalog device that monitors TPS sensor would do it for most of us. But carbeureted cars would simply have no means of logging this.

[Cody]

"AWD"
Winnar! :D

[Dean]

I think Maximum Acceleration works. It implies minimal split and maximum throttle.

[jim.gandy]

Thanks guys, keep 'em coming... and, yes, Mr. Khamis, you made me laugh...:p

I have to say that for the second day in a row, Scott got under my skin, and I don't think he intended to. On Dean's PAX-critique thread, Scott said words to the effect that a locally-created indexing system couldn't be impartial. In a later post he exempted theory-based index systems, but for an hour or so he had me grinding my teeth.

Anyway, this is a great opportunity for me to make one thing absolutely clear...

I promise that if Reno Region were ever to adopt HAP as its official indexing system, I would automatically and forever be barred from competing for a HAP trophy. I'd still autocross, because I love to, but my name would disappear from the HAP results listings.

[jim.gandy]

Scott,

I also envision a device like you describe, perhaps using some kind of thin, touch-pad switch. But where do I find a proper clock/timer, one that counts in hundredths if not thousandths? It seems like it would be a simple device, but I don't see it just sitting on the shelf at Radio Shack.

Also, the device you describe wouldn't produce accurate results in cars that can't completely defeat traction control (I don't know for a fact, but it seems to me I've read about cars like that). Any simple answers for that one?

[sperry]

Thanks guys, keep 'em coming... and, yes, Mr. Khamis, you made me laugh...:p

I have to say that for the second day in a row, Scott got under my skin, and I don't think he intended to. On Dean's PAX-critique thread, Scott said words to the effect that a locally-created indexing system couldn't be impartial. In a later post he exempted theory-based index systems, but for an hour or so he had me grinding my teeth.

Anyway, this is a great opportunity for me to make one thing absolutely clear...

I promise that if Reno Region were ever to adopt HAP as its official indexing system, I would automatically and forever be barred from competing for a HAP trophy. I'd still autocross, because I love to, but my name would disappear from the HAP results listings.
I'm sorry if you're feeling offended Jim. Never have I once posted anything directed towards you personally.

The talk about 30th place to 25th place was directly from your own reference to those two positions in your post regarding Adam, and not directed at you or anyone else in particular.

And my mentioning of a local PAX being "personal" or "favoritism" was not to imply the person generating the factors would be doing so to help themselves, but to point out that creating factors to correct individual perceived injustices in the region is by definition "favoritism" even if done with the best intent.

My comments are intended to be constructive, and are intended to bring to light the issues that PAX and HAP have to overcome if they're to be more useful and more accepted. If my attempts at constructive criticism are being taken personally, I'll just keep my mouth shut, since that's not at all my intent.

I will just suggest that if you can't answer the question "Why is my HAP factor the number that it is?" for every competitor and have that answer be based solely on verifiable and quantifiable data they themselves can use to calculate the number on their own, then HAP is at best just as unfair as the PAX system it's attempting to replace regardless how much "better" it works.

["A" Stocker]

You guys need to ask Rick Brown, his car has the Pi System which records all that data and then some: throttle position,steering position,wheel speed, etc. He uses it all the time in Sac. and the results are pretty interesting. I think he said he would have used it at Stead when he was there, but it was just to cold and he didn't want to bother setting out the transmitters. On the lap top it even gives a course map view of your speeds at different points on the course.

[Jamin]

Quote:Originally posted by MikeK
Originally Posted by jim.gandy http://www.renoscca.org/forums/images/buttons/viewpost.gif (http://www.renoscca.org/forums/showthread.php?p=1283#post1283)
Can anybody think of a good name or acronym we can use for "wide-open throttle with drive wheels not slipping and no traction control?"

"AWD"

Priceless!

[sperry]

I think Maximum Acceleration works. It implies minimal split and maximum throttle.
I came up with a better one this morning: "Terminal Acceleration"

Maximum acceleration implies the car is accelerating as fas as it can, but that means it could be limited by power, traction, traction control, less than 100% throttle, etc. i.e. the car can't accelerate more, but it's not necessarily because the motor is using all its potential.

Terminal acceleration implies that the motor is accelerating the car as fast as it can but that the limiting factor is external to the car... i.e. no tires are slipping, no traction control is on, and the driver is in fact attempting to accelerate even more, but the car has reached terminal acceleration.

[Kevin M]

That's not what "terminal acceleration" implies to me Scott!

[jim.gandy]

Scott, I like it. Then we could generate data that we could call "Time At Terminal Acceleration." So we could end up saying, those Subarus have bodacious TATAs...

[solonut]

wouldnt "terminal acceleration" hitting a wall at top speed?? ;) hit the wall acceleration is terminated.......:)

Its friday....lets stop typing and go to the track!!!!!!!!!!

[82AS]

You boys need to have a drink or two before you answer any more questions.

[Kevin M]

If you're buying, I'm in!

[Cody]

I came up with a better one this morning in the shower: "Terminal Acceleration"


Oh boy.

[sperry]

Oh boy.
Yeah, I figured that was TMI for this board... on SECCS, everyone already knows I do my best thinking in the bathroom.

But thanks for undoing my ninja edit. :rolleyes:

[Cody]

Any time. :D

[S2kreno]

once you max out your acceleration (hit your terminal velocity) then you are no longer accelerating. but you're probably going really freaking fast. we could call it rff. pronounced 'arf.'

[jim.gandy]

The HAP results sheets for Rounds 4 and 5 at Hawthorne are attached to this post. As usual, the PAX results are listed alongside to make comparison easy. Don't forget that these listings "integrate" the Ladies with the Open entrants.

Some notes: remember that weather played a big role in Round 5's results, as one-third of the runners had a wet track. That's one reason an E Stock Miata cracked the Top Ten in HAP -- the other reason is that it was a Miata course, no straights to speak of. I also think Don Smith is getting faster and faster, to my chagrin.

Hawthorne's elevation is around 4,300 ft. HAP was designed for Stead, which is 4,900 or so. That makes a small but real difference in the altitude effects.

[MPREZIV]

Reno Stead Airport is 5046 feet according to their website, on the tarmac.

http://www.renoairport.com/about_the_airport/reno_stead_airport.php

[jim.gandy]

The High Altitude Performance (HAP) index results for Round 6, June 7, 2008, are attached.

[nmhansen]

Jim, my car is forced induction.

[jim.gandy]

Attached are HAP results for Round 6 (corrected) and Round 7.

Remember that the HAP results sheets are "gender-neutral." Open and Ladies are listed together.

Reno Region's regular results listing can be found by going to the region's home page, renoscca.org, and clicking on the Solo Results button.

[dknv]

I couldn't remember what the middle column indicator was for, had to hunt and finally spotted it in post #81 of this thread:
....
The HAP factors are chosen by asking three additional question about the car being driven.

1) Do you have Forced Induction?
2) Is your Car listed in the "In-class disparity list" (yes means your car is at a disadvantage due to differences exemplified at altitude)
3) Is your car eligible for the Street Tire Handicap.

Then its combined with PAX to create HAP
..
The In-Class Disparity List is as follows (again, pulled from the above link):
SS Elise ('05+); Boxster S ('05+)
AS S2000 (all); 911 non-turbo ('95-'98); Boxster (all)
DS C320; Eclipse ('06+); Maxima ('04+)
ASP All Lotus except turbos and Esprit V-8; all Porsche non-turbo
BSP 280ZX non-turbo; 350Z; S2000; RX-8
===============

Couple of questions: ST cars are already receiving a st factor against pax, what is it at altitude that influences an additional handicap?

Also, what is it about the S2000 in AS that causes it to be in the disparity list? Why is an RX-8 in the disparity list in BSP? (I think I've only ever seen 1 BSP RX-8 running once, in all of the events I've run in the last 3 years.) And interestingly, I was talking with our ASP Lotus driver yesterday, and he mentioned the horsepower variance between his car, and the Corvettes in his class, so is that the sole reason the Lotus is in the ASP disparity list?

[S2kreno]

Hi Debbie,

If you ever ran an S2000 at this altitude you wouldn't have to ask :) I used to take mine to the Bay all the time and the difference in pickup (and these are already pretty challenged at the low end) was very apparent. The poor little suckers are gasping for air up here. Now I have a Lotus but haven't taken it down I-80 because the road's too bumpy and I don't want to destroy my vertabrae... I may just have to try it out, sacrifice my body for science....unless Bryan wants to sacrifice his :rolleyes:

[dknv]

Hi Debbie,

If you ever ran an S2000 at this altitude you wouldn't have to ask :) I used to take mine to the Bay all the time and the difference in pickup (and these are already pretty challenged at the low end) was very apparent. The poor little suckers are gasping for air up here. Now I have a Lotus but haven't taken it down I-80 because the road's too bumpy and I don't want to destroy my vertabrae... I may just have to try it out, sacrifice my body for science....unless Bryan wants to sacrifice his :rolleyes:
I could say the same thing for the RX-8, based on seat-of-the-pants feel, but was wondering if there was some kind of numerical data to support it. For example, at the El Toro ProSolo, the MR2 Turbo (which is also classed in BStock) beats the RX-8 from the launch to 60', by about .3 seconds. (I have always said the RX-8 has no torque coming out of a corner, so it is important for us, like the Miatas, to keep up momentum.) Granted, that the turbo and the lighter weight of the MR2 accounts for much of the launch advantage, but this is the kind of data I was wondering about.

btw: don't hurt your back.

[Kevin M]

Debbie, the in-class disparity usually refers to smaller, normally aspirated engines suffering slighty more power loss at altitude than larger or forced induction engines.

[jim.gandy]

The honest answer about the in-class disparity list, straight from the HAP guy (me)...

The inclusion of an "in-class disparity list" in HAP is simply an acknowledgement that the SCCA classes were created without giving thought to the effects of altitude. Cars in a given class may be equal (in typical autocross performance) at sea level, but they can sometimes be very unequal at high altitudes due to the effect of altitude on engine output at full throttle.

As to what cars are currently included on the In-Class Disparity List, I freely admit that this is the least-developed part of HAP. It was guesswork on my part, and the current list was intended to be no more than a starting point.

Obviously, nobody has the time to go through the hundreds of cars classed by the SCCA and evaluate each one. The current list simply gets the idea out there, and the last line of the HAP Factor Chart sums up where we might go from here: "To have a car considered for eligibility or exclusion from this list, contact Jim Gandy at jrgandy@peoplepc.com."

IF (a very big if) HAP or something like it were ever to be put into practice, then there would probably be someone or some small committee in charge of overseeing HAP. What I have in mind is that drivers who want to change the In-Class Disparity List would have to do the homework and present a fully-developed case to whoever runs HAP. The person or committee would then decide. Barring some major mistake, changes would only be made in the off-season.

Currently, HAP is just being tested and evaluated, so mid-season changes are possible.

If Debbie were to ask for the B Stock RX-8 to be put on the Disparity list, it would take more than just a comparison of horsepower numbers, or even of output/RPM curves. Remember that what is critical to HAP is differences in the fraction of run time that a vehicle spends at Wide Open Throttle. A convincing argument would demonstrate that the RX-8 uses a lot more WOT up here as opposed to, say, Sacramento, while another leading B Stock car (supposedly with more horsepower) uses very little additional WOT up here. A key thing to show, in my opinion, is that some leading car in the class is so powerful that it rarely gets to use full throttle, at any altitude. That means it is affected very little by altitude, and opens the door to possibly putting lower-powered cars on the disparity list. By implication, then, the lower classes will probably never see cars on the disparity list. The current list has some entries for D Stock, and that was intended to test the limits of the concept and invite feedback -- to make people think.

Thanks, everyone, for checking out the HAP results and posting your thoughts and questions.

[S2kreno]

"To have a car considered for eligibility or exclusion from this list, contact Jim Gandy at jrgandy@peoplepc.com."


Jim, you might just be the bravest man I know :)

[scarabracer]

I am not sure that I understand.... If H.A.P. is suppose to compensate for displacement than why does my X.P. car have a more favorable factor than it does in P.A.X.? Dont get me wrong. Im totally good with it, I am just not sure why that is.

[sperry]

I am not sure that I understand.... If H.A.P. is suppose to compensate for displacement than why does my X.P. car have a more favorable factor than it does in P.A.X.? Dont get me wrong. Im totally good with it, I am just not sure why that is.
It's all relative to the other HAP factors. You can't compare it directly to PAX.

[Kevin M]

All cars get a "more favorable" HAP. It's how much more favorable that separates them.

[jim.gandy]

Scott and Kevin are correct, Jeff. Both HAP and PAX use A Modified as a starting point (factor 1.000), and compared to A Mod, X Production does seem to have a "softer" factor in HAP than in PAX -- 0.3 seconds softer on a sixty second course.

But compare factors with other classes. For example, compare XP to the wimpiest class, H Stock. The difference between their PAX factors is .085, which is 5.1 seconds on a 60-second course. HAP, however, gives a difference of .110, which is 6.6 seconds, or a full 1.5 seconds more. If we had a national-caliber H Stock entry here in Reno Region, you (in XP) would have to pedal 1.5 seconds harder to beat him in HAP than you would in PAX. That's how your big-bore car has a "less favorable" HAP factor.

[scarabracer]

thx. I see the big picture now. Looks like I will be a pax fan after all. It has taken me 16 years to put this car into a top 10 pax. probibly take me 16 more to find another 1.5 seconds to compete in hap!!!!

[jim.gandy]

A couple of responses to Jeff's post...

I guess it's human nature to be a "fan" of whatever system a person thinks will give him/her an advantage. ;-)

Jeff, of course, doesn't need to "find another 1.5 seconds." At Round 7, he was second in PAX and second in HAP, too.

Jeff's post implies that some hypothetical well-prepared and driven H Stock car would beat him by 1.5 seconds in HAP. Not so. Here's the important part: In PAX, Jeff should beat that hypothetical HS car by 1.5 seconds, but they should be close to even in HAP. Jeff's already competitive in both systems. PAX, however, is biased at high altitude so that high-horsepower-to-weight cars dominate the overall standings, for the most part. With HAP, lower-powered (but well-prepared) cars can be competitive, too. At least, that's the goal.

I know Jeff may have made his statement in jest, and maybe he does "see the big picture now." If so, I apologize. I'm just trying to make sure as many people as possible understand how HAP works.

Once again, the whole point of the HAP experiment is to explore the reasons why PAX is unfair at our altitude, and to offer an example of how we might go about doing something better than PAX.

[jim.gandy]

Here are the HAP results from Solo Rounds 8 and 9, June 28-29 at Stead.

As always, the PAX results are listed alongside for convenience.

Remember that HAP "integrates" Ladies and Open competitors.

Also keep in mind that the Round 8 and Round 9 courses were very "open" and pretty fast, probably the most open courses this Region has put on at Stead. Perhaps not as open and fast as the full course at Hawthorne or some Lovelock past events, but still open enough to skew the results even further towards power and away from handling.

[jim.gandy]

The High Altitude Performance Index results from the July 12-13 weekend's Solo events, Rounds 10 and 11, are attached.

As before, the corresponding PAX results are listed alongside for convenience.

Remember that these results combine Open and Ladies classes instead of listing them separately. Congrats to our fast ladies for their great finishes, Debbie Kerswill 5th overall on Saturday and Patty Evans 4th overall on Sunday!

Also, I've decided not to do any mid-year adjusting to the 2008 HAP factors. Even though HAP is still in the "testing and evaluation" phase, the factors seem to be accurate enough to be fair, IMO.

[jim.gandy]

I guess everybody's worn out on the subject of HAP versus PAX -- no comments posted since Rounds 10 and 11.

Here are the HAP results sheets from Rounds 12 and 13, July 26-27 at Stead Airport. As always, the PAX results are listed alongside for comparison. And, the Ladies are listed with the Open results, not separated. (How about Patti Yeo, third in both HAP and PAX in Round 13?)

There was something decidedly different about Saturday -- somebody other than Miller or Yeo topped the list, and a stock Miata almost cracked the top ten. It was all back to normal on Sunday, however. Food for thought for the Course Design thread...

[jim.gandy]

The High Altitude Performance (HAP) Index results from Reno Region's Solo Rounds 14 & 15 are attached. These were the events held at Reno-Fernley Raceway, and are the first Reno events in a long time to feature significant uphill and downhill sections.

As usual, the HAP results are displayed alongside the PAX results for easy comparison. And, there is no gender separation in HAP -- Ladies and Open entrants are listed together.

Congrats to Debbie Kerswill, scoring a terrific second place in HAP on Saturday (PAX placed her fifth). No wonder SportsCar magazine lists her as one of the favorites to do well in B Stock Ladies at the Topeka Solo National Championships in September.

[jim.gandy]

The HAP results for Reno Region's Lovelock autocrosses, Rounds 16 and 17 of our 2008 Solo Championship Series, are attached to this posting.

As always, keep in mind that Open and Ladies are listed together in the HAP results. In the results sheets, you'll find the driver's name, class, car and raw time, the answers to the three HAP questions about the car, the resulting HAP factor and the calculated HAP score, which is simply raw time multiplied by the HAP factor. Listed alongside the HAP results are the PAX results, so you can compare them easily.

The two Lovelock events were very fast and open, with lots of Wide Open Throttle. On the other hand, the airport had just been seal-coated, so traction was limited. There were many spins among the cars with high horsepower. A pivot-cone 180 on Sunday was especially difficult to execute cleanly. Congrats to Bob Williamson, who hadn't been in the Top Ten in HAP since Round 11 back in July -- his '96 Z06 and his careful driving were the right combination on Sunday at Lovelock, scoring first place in both HAP and PAX.

[jim.gandy]

Attached are the HAP results for Reno Region's final two Solos of 2008.

As always, the PAX results are listed alongside for easy comparison. Remember that in these listings, Open and Ladies are integrated.

Some comments based on a very brief look at these results:

Note that in Round 18, Chris Kannan (a nationally-competitive California driver in a C Stock Miata) took first place in HAP, beating even the Yeo/Miller Corvette. Then on Sunday, Kannan dropped to third in HAP, a "swing" of some nine-tenths of a second in the HAP scores between Chris and Ken Yeo. Questions: was there something about the Round 18 and 19 courses that allowed a Miata to place so highly, and was there a difference between Saturday and Sunday that caused the "swing?"

My speculation is that Saturday's course -- which was an exact copy of the West course at the 2006 Topeka Solo National Championships and had essentially no straight stretches -- really allowed the Miata and the Corvette to compete on an equal footing using the HAP handicap factors. Then on Sunday, when the course was run backward, there was one substantial difference: a long straight (perhaps 500 feet?) was added right after the start, making all cars accelerate from the bottom of first gear. This type of course feature is death to low-horsepower cars, and to my mind it resulted in the differences you can pick out in the Saturday and Sunday listings (another example, my own performance in E Stock, 17th on Saturday and dropping to 21st on Sunday).

Some "hat tips" from the results: Debbie Kerswill did a beautiful job on Saturday, third in HAP and fifth in PAX. Daughter Rachel was impressive with a 13th in HAP on Sunday. Another young driver, Adam Kovac, finished 16th in HAP on Sunday in an H Stock Civic. And how about Joe Ysais, the highest-placing "local" driver on Sunday, 6th in HAP in his Corvette?

It was interesting to see what effect course design had on our results, so thanks go out to chairs Pat Housel and Lexie Wallace for bringing a little bit of Topeka to Reno.

I'll be working up the season-long HAP "final standings" soon.

[dknv]

Note that in Round 18, Chris Kannan (a nationally-competitive California driver in a C Stock Miata) took first place in HAP, beating even the Yeo/Miller Corvette. Then on Sunday, Kannan dropped to third in HAP, a "swing" of some nine-tenths of a second in the HAP scores between Chris and Ken Yeo. Questions: was there something about the Round 18 and 19 courses that allowed a Miata to place so highly, and was there a difference between Saturday and Sunday that caused the "swing?"2 things come to my mind:
Chris Kannan and I chatted after Sunday's events, and he told me he informally timed some of the cars in the 4th run group. His observations were that the corvettes / viper, on average, were leaving the start line and reaching the first slalom cone in about 6 seconds (I think he mentioned that Ham's SM2 corvette reached it in 5.7 secs). Whereas, it took 8 seconds to reach it in my car.

Now that 2 second advantage could have been the results difference in and of itself, but the other point Chris and I agreed on was that the course flowed differently in the opposite direction on Sunday, causing he/Pam, and me, to have to make at least one more downshift decision going into the short offset slalom. I would be interested in hearing if this effect was felt by others/other vehicles.

[Cody]

On Sunday, I definitely had to downshift to 1st 3 times instead of the 2 1st gear downshifts required by Saturday's course. Sunday was definitely a more challenging course for me, specifically keeping the car in the right gear without destroying the drivetrain.

["A" Stocker]

Kenny Yeo's fastest runs on Sunday were using 1st gear at the 3 cone turn around. They also improved by 2 sec. from Sat. to Sun., which tells me the course flowed way better on Sun. than Sat.

[dknv]

I thought the Saturday course had better flow due to wider corner exits. However, the longer straight on Sunday, along with the finish being a little earlier in the course, may be the explanation for Ken Yeo's time to be 2 seconds shorter.

[jim.gandy]

Keep in mind that the "long straight" on Sunday was created by shortening Saturday's seven-cone slalom by one cone. That alone should have made Sunday's times shorter than Saturday's, if the "flow" stayed the same.

I don't know what others thought, but I thought the finish section on Saturday (accelerating out of the final cones of the seven-cone slalom and still tucking back into the gate that funneled you to the lights) was a fun challenge.

[Cody]

^I thought so too.

[jim.gandy]

I finally got around to completing the HAP worksheet, so it now calculates season points. The final standings are attached. Remember that HAP doesn't break out Ladies and Open.

Before the '09 season begins, I'll be adjusting the HAP factors.

[jim.gandy]

Might as well drag this poor old thread out into the daylight once more --

did you notice in the new FasTrack Solo bulletin that the Solo Events Board "will be considering" a proposal to used a "forced induction handicap factor" in X Production? Maybe HAP's day will come...

[Kevin M]

I saw it, but thought they were referring to weight penalties.