Street Tires vs. Race Tires

[sperry]

The hottest topic in Reno!

Let's keep it civil... what you you all think about the new ST PAX factor?

[nmhansen]

I'm glad I'll be able to flop back and forth between the year.

I'm definitely going to be trying out race tires next year just to see what its like in my own car and we'll go from there. But, its nice to always be able to go back to street tires if I need to.

[TracDaz]

At 5,000 ASL, the PAX is really only for those with boost or big cubic inches. The rest of us just watch the show...

[sperry]

At 5,000 ASL, the PAX is really only for those with boost or big cubic inches. The rest of us just watch the show...
Street Tire PAX? What's that got to do with horsepower and altitude? In fact, the evidence shows that it's the big power cars that lose out the most under the street tire PAX rules, since their advantage (esp. at altitude) tends to be on the straights where race tires help you the least.

If you're just watching the show 'cause you think the Miata isn't effected by the street tire PAX, you're likely going to get beat up on by another Miata that's making smarter tire decisions based on the new ST PAX factor.

[solonut]

Street Tire PAX? What's that got to do with horsepower and altitude? In fact, the evidence shows that it's the big power cars that lose out the most under the street tire PAX rules, since their advantage (esp. at altitude) tends to be on the straights where race tires help you the least.

If you're just watching the show 'cause you think the Miata isn't effected by the street tire PAX, you're likely going to get beat up on by another Miata that's making smarter tire decisions based on the new ST PAX factor.

Hey Scott.....he drives a S2000 now....look at his post with car type....

Russ you should be able to hang wth the Saturn Sky is AS....they are real close on race rubber.I have a freind who ran both last year.

[dknv]

I think Pat Riley running the S2000 was pretty competitive when he was up here.

[Dean]

If anybody is bored and wants to see the calculations I did using National SP and ST results, say so and I'll post the spreadsheet somehow.

EDIT: Here it is... Just as it was sent to the board.

Due to weather, a bunch of the data is bad... I am attaching a spreadsheet that can be quite confusing but includes all the data for comparable class trophy places. It further attempts to isolate the actually comparable cars on an individual and class basis.

I have highlighted what I believe is the useful and most valid data in green and it runs from the high .93s to the low .97s... This just goes to show how hard this is and how it depends on the course and car

That said, this is a significant change from the last time I did this when it ran from the .92s with nothing above the low .96s. At that time we erred on the side of race tires and went with .968 which was the same simple 60 seconds on R compound vs. 62 seconds on streets.

I am going to suggest the same thing again. R=60 VS T=61.5 which is a 1.5 second handicap and comes out to .9756 which is higher than all of the data I remotely trust.

I can round either way to .975 or .976 or leave it at 4 decimal places if the software supports it.

I am also threatening to do a statistics based replacement for PAX based on all of the nationals data....

If you care, the most comparable cars are:

89 CIVIC SI
STS places 1-3
FSP places 1
93 Civic
STS places 4
FSP places 2

Honda CRX
88-91 STS2 places 1,3-8
86 CSP places 6

Mazda Miata
92 STS2 places 2,9
91-99 CSP places 1-5

BMW 325i,is
89-95 DSP places 1-7
93 STX places 2,6-7

I'll try and answer any questions on the data if I can. (Ignore the hidden columns, they are from my PAX work.)

[nmhansen]

Yes, please.

[Dean]

Yes, please.See above.

[Kevin M]

Maybe we can arrange a closed-session test at Stead sometime this year? Maybe get some drivers who have the ability to run R-comps and high-end street tires back-to-back?

Also, can you run STU vs. BSP Dean? I know the classes dont' exactly corroborate like STs and DSP/CSP, but it's still an okay indicator to those of us who know that BSP has faster cars.

[nmhansen]

"some" drivers will not produce worthwhile stats.

[Kevin M]

"some" drivers will not produce worthwhile stats.

Yeah, and the results would probably be skewed towards street tires, since everybody who would have both mostly runs on those.


...I'm not seeing a problem here Nick.

[nmhansen]

Yeah, and the results would probably be skewed towards street tires, since everybody who would have both mostly runs on those.


...I'm not seeing a problem here Nick.

To clarify, I meant "some" in reference to quantity not quality :p

I'm sure you could even argue that nationals isn't exactly that statistically significant either, but its the best we have.

[Dean]

Nationals is as close to statistically significant as it gets. In my work on a PAX replacement, it became clear that the tour events don't cut it statistically at all.

I tried to do STU, but there are no comparable cars between the two. The M3 in 7th was my only chance really.

Swapping tires on the same car is a problem as is having the same driver drive both.

Setup on a car for T vs. R is significantly different in camber and likely spring rates as well as other stuff.

Yes, a driver could drive both well, but it would take many runs of practice in each, and the results would still be dubious.

IMHO, the best data out there are the best drivers driving the best prepared cars. Please note I only compared trophy drivers. In general, there were 3.5 X #of trophies number of actual drivers in each class.

Probably the biggest thing to remember is that Rs only have an advantage when a T would be using 100% of their traction. So, the tighter and more heavily transitional the course is, the more advantage R has. The straighter and smoother the course, that advantage goes away.

Think of the two extremes.

A drag strip and a skid pad.

Unless the car can break the tires loose on launch, there is no advantage to the R car on a drag strip. Times should be close to identical.

On a skid pad, the R uses it's traction advantage 100% of the time and should be faster by more or less whatever percent greater traction they have over the T tires.

So, it really depends on the course as much if not more than the car or the driver.

So I took the best cars and drivers and two significantly different courses from nationals and made our best statistical guess given that the preperation levels for ST and SP are not the same.

Is .975 perfect? I would be the first person to tell you no, but it is better than nothing.

Don't get me started on PAX... As far as I can tell, there is no math or statistics behind them at all. :rolleyes:

[Kevin M]

You can just put the STU Evos and STis up against the BSP Evos and STis Dean. Not perfect, but it's the only data you have for comparing heavier cars. Also, are you using actual trophy placings, or top raw scores? I would throw cones out for this analysis.

[sperry]

Here's what it takes to get statistically meaningful data:

500 pairs of cars. Each car in the pair is identical to it's pair-mate wit the exception of the tires, but each pair is a different power/layout/type/class/preparation level/etc from the other pairs.

1000 drivers. Each driver is an expert at setting up and driving one particular car at the absolute limit on the tires for that car.

50 different track layouts, from a drag strip, to a pure skid pad, to 48 varying tracks somewhere in between.

50 different weather conditions, from blazing hot, to pouring rain, to light snow, to everywhere in between.

10 brands of tires, that's 5 different "top" street tires, and 5 different "top" R-comp tires.

50 million set of tires. That's two sets of tires of each brand (one practice set to make sure the driver is at 10/10ths on that brand of tire on that particular track, and one test set to run laps on from brand new until they're corded) for every driver in their car, on every track, in every weather condition.

Assuming each driver can get through two sets of tires in a day, and each driver can run 5 days a week w/o getting tired and burnt out thus going slower than the car's best possible time, and assuming all 1000 drivers can somehow all run at the same time at some super-massive test facility, and assuming the weather conditions will somehow luckily match the required test scenarios without every waiting for the right weather... this test will only take a little over 96 years to complete.

Now that would generate some statistically useful data. Unfortunately, it would all be invalidated by the fact that the drivers would all be old geezers driving slowly around with their left blinkers on the whole time by the end of the test cases.

[Dean]

You can just put the STU Evos and STis up against the BSP Evos and STis Dean. Not perfect, but it's the only data you have for comparing heavier cars. Also, are you using actual trophy placings, or top raw scores? I would throw cones out for this analysis.No, but you can. :P

I have no interest considering the changes in boost.

The M was the only NA possibility, but there is no comparable M in SP I can find.

[TracDaz]

Scott,
The race tire-equipped car with surplus torque (read Corvette, etc) will carry more speed on to the straight and will be able to accelerate sooner and harder than a similar car/driver on street tires.

At the end of the straight, an R-tire car can continue accelerating longer as their braking time is shorter, plus they can enter the corner off the straight at a higher speed. Your argument that race tires are least effective on the straight seems to suggest that those points don't hold much water on a Solo course. Can you share with us way this is? Thanks!

[sperry]

Scott,
The race tire-equipped car with surplus torque (read Corvette, etc) will carry more speed on to the straight and will be able to accelerate sooner and harder than a similar car/driver on street tires.

At the end of the straight, an R-tire car can continue accelerating longer as their braking time is shorter, plus they can enter the corner off the straight at a higher speed. Your argument that race tires are least effective on the straight seems to suggest that those points don't hold much water on a Solo course. Can you share with us way this is? Thanks!

What you're describing is independent of the type of car. A Miata on race tires will also carry more speed onto the strait than a similar car/driver on street tires. Also, at the end of the straight, the race tire Miata will be able to out brake a street tire Miata. That's true regardless of the type of car in question. The thing to remember is that the acceleration and braking advantages of race tires are far less important than the cornering advantage of race tires. Regardless of car type, the cornering speed of a race tire car will be much higher than the cornering speed of that same car on street tires, and that's really where the lower times come from.

The reason why is, you will never generate the same G force braking or accelerating as you can while turning. This is even especially true at autocross where the tight courses make cornering speeds that much more important, as there is relatively little acceleration and braking time as a percentage of total time on course. Cornering is king.

Take a look at YouTube- Chasing a Porsche 930T. Granted it's at a track, not autocross, and granted I'm pulling some pretty heft braking manuvers, but that's cause I'm braking from 130mph, not from 65. But what you'll see is that while I'm turning at 1.5G, I'm braking a 1G, and accelerating at only 0.5G. In essence, accelerating is by far the least use of traction.

To illustrate, here's my G-G plot from that session:

http://www.seccs.org/images/misc/G-G_plot_5-19-07.jpg

As you can see, the it's the race tire advantage in the corners that really make the race tires faster overall. Using the 1.5G/1.0G/0.5G turning/braking/accelerating numbers from my telemetry, if my street tires are let's say half as sticky as my race tires, then my G's are cut to 0.7G/0.7G/0.5G. So, while I'm cornering at half the speed, I'm accelerating at exactly the same pace!

So that overpowered Vette on race tires has to race against street tire cars who have a factor designed to counter the cornering effect of race tires, thus taking away the Vettes advantage since their advantage is in the area least effected by tire type.

To put it more simply: a Vette's greatest advantage is on the straights where it can use all that horsepower and torque to make up for being slower in the corners. On a long straight, that Vette isn't using 100% of its traction. So the street tire PAX doesn't help them as much as it helps a car like a Miata which relies on its cornering speed.

[jim.gandy]

Really interesting exchange of views going on here. I think the R vs ST problem is similar to (really a part of) the challenge of understanding the effect of high altitude on autocross times.

It's true that very few cars have the torque to overwhelm their tires when they're accelerating on a long straight. But, here's something you might consider. The last portion of a corner and the first portion of the following straight are a transition zone. A Street Tire car will corner at a lower speed and take longer before it's "hooked up" (even longer for higher-powered cars), which results in a speed penalty that it suffers from all the way down the straight, no matter how long or short the straight is. Since the ST car starts its acceleration-only phase later and at a lower speed, it's slower at every point on the straight (unless the straight is so long that terminal velocity is reached!). In my opinion, it is not true that the major difference between R- and ST-equipped cars is found mostly in corners, especially on the more-open type of courses we favor here in Reno Region. And, in my opinion, tire type affects both high- and low-power cars in a similar way and to a somewhat similar amount.

Now, consider the effect of traction control. And consider the effects of boost and lag for forced-induction cars. Yep, it doesn't take long before things get really messy from a theoretical viewpoint. Guys, this is why I've been a consistent advocate of our region trying to do some testing. Logical analysis can take the R vs. ST debate only so far (same for the high altitude/PAX debate, too). It's very easy to laugh at the idea of testing, but the problem remains, we have very, very little real-world information to go on.

Enough whining on my part. I'm enjoying the forums (and I was apprehensive about them); thanks, Scott! :)

[sperry]

Really interesting exchange of views going on here. I think the R vs ST problem is similar to (really a part of) the challenge of understanding the effect of high altitude on autocross times.

It's true that very few cars have the torque to overwhelm their tires when they're accelerating on a long straight. But, here's something you might consider. The last portion of a corner and the first portion of the following straight are a transition zone. A Street Tire car will corner at a lower speed and take longer before it's "hooked up" (even longer for higher-powered cars), which results in a speed penalty that it suffers from all the way down the straight, no matter how long or short the straight is. Since the ST car starts its acceleration-only phase later and at a lower speed, it's slower at every point on the straight (unless the straight is so long that terminal velocity is reached!). In my opinion, it is not true that the major difference between R- and ST-equipped cars is found mostly in corners, especially on the more-open type of courses we favor here in Reno Region. And, in my opinion, tire type affects both high- and low-power cars in a similar way and to a somewhat similar amount.

Now, consider the effect of traction control. And consider the effects of boost and lag for forced-induction cars. Yep, it doesn't take long before things get really messy from a theoretical viewpoint. Guys, this is why I've been a consistent advocate of our region trying to do some testing. Logical analysis can take the R vs. ST debate only so far (same for the high altitude/PAX debate, too). It's very easy to laugh at the idea of testing, but the problem remains, we have very, very little real-world information to go on.

Enough whining on my part. I'm enjoying the forums (and I was apprehensive about them); thanks, Scott! :)
Jim, I totally agree with your assessment of ST effect entering a long straight. I don't think there's any flaw in the logic that an ST car will be slower. This effect is supposedly accounted for by the ST PAX factor.

However, when we start comparing low vs. high horsepower cars in the same class (or in Open PAX... though that's another can of worms), I think the low horsepower cars gain more than the higher power cars on the straights. The high power car has to use the straights to press it's advantage over the cars that are cornering more quickly, and in doing so it can make more use of the race tires than the low power cars. In the same way that an open course helps the high power car, the ST PAX factor hurts them, because relatively speaking the ST factor helps the slower cars the most right in the spot where the high power cars need to have their biggest advantage.

[dsmith]

I'm curious if we'll have many "mix and match" class battles this season, like AS last year with Randy and John. Or will most of the classes be a one tire group, either race or street?

Since no one seems to want to try to achieve any empirical data by real world testing (which granted would supply numbers that everyone could argue are inaccurate for some reason or another - just like now) we're left with using best guess estimates. At what point do we know the modifier is correct? Is there a way-point we reach that we can say "Yep, it's an even handicap now" because car X finally beat car Y? Do we wait until one group or other becomes completely uncompetitive through all classes and then readjust from there?

It seems to me any kind of test, even one not perfect and not using all available options, would be better than "guessing." Granted, the results would probably burst one side's bubble, but the way we're doing it now - to me anyway - is just like selecting the NCAA Final Four in November based on all the expert's polls, instead of actually playing out the season on the basketball court.

[sperry]

I'm curious if we'll have many "mix and match" class battles this season, like AS last year with Randy and John. Or will most of the classes be a one tire group, either race or street?

Since no one seems to want to try to achieve any empirical data by real world testing (which granted would supply numbers that everyone could argue are inaccurate for some reason or another - just like now) we're left with using best guess estimates. At what point do we know the modifier is correct? Is there a way-point we reach that we can say "Yep, it's an even handicap now" because car X finally beat car Y? Do we wait until one group or other becomes completely uncompetitive through all classes and then readjust from there?

It seems to me any kind of test, even one not perfect and not using all available options, would be better than "guessing." Granted, the results would probably burst one side's bubble, but the way we're doing it now - to me anyway - is just like selecting the NCAA Final Four in November based on all the expert's polls, instead of actually playing out the season on the basketball court.
Here's the way I look at it:

The number is "right" when those that are complaining about it are split equally between people running on ST and RT. I don't think it can ever be "mathematically fair" but if the majority of those racing feel like it's fair, then it's as right as it gets.

Which is why I support the recent change in the factor. We weren't hearing any of the ST folk complaining, and we were hearing more and more from the RT folks. So it was time to push the number in favor of race tires. If after this season we have a mob of ST people who feel like they're being shorted, then it's time to revisit the factor again.

[TracDaz]

OK, I want to be counted as one who feels the race tire crowd got more of a benefit than was deserved in this latest adjustment. They were the squeakiest wheel in this case and they got their deserved grease, as Scott suggests. My biggest beef is in the Stock or Street 'anything' classes, that Race tires are allowed. It's the call of the whole national SCCA squad, but the essence of street-legal cars in a race setting is that they show and race on the tires that got them there. That we choose to see a 2008 vintage R-DOT tire being anything other than a race tire with two grooves shows how far technology has progressed since BF Goodrich introduced the first R-DOT back in the 80s. In the 80s or 90s there weren't any 140 or 200 wear rating street tires, either. R-DOTs are what, 40 wear rating? That tells me they are substantially stickier than street tires.

This year, we'll see Rs beating STs and, as Scott suggests, an adjustment will be made. I would suggest that an assessment is made after the first 1/3 of the season draws to a close. If another adjustment is called for, it would allow for spectacular finishes at the end of the season. Whattya think?

[Kevin M]

Zero chance of an adjustment to the street tire factor during the season, Russ. That's not fair to anybody.

[nmhansen]

Not fair at all.

You could just switch back and forth depending on adjustments.

[solonut]

Not fair at all.

You could just switch back and forth depending on adjustments.

My thoughts exactly....

[sperry]

OK, I want to be counted as one who feels the race tire crowd got more of a benefit than was deserved in this latest adjustment. They were the squeakiest wheel in this case and they got their deserved grease, as Scott suggests. My biggest beef is in the Stock or Street 'anything' classes, that Race tires are allowed. It's the call of the whole national SCCA squad, but the essence of street-legal cars in a race setting is that they show and race on the tires that got them there. That we choose to see a 2008 vintage R-DOT tire being anything other than a race tire with two grooves shows how far technology has progressed since BF Goodrich introduced the first R-DOT back in the 80s. In the 80s or 90s there weren't any 140 or 200 wear rating street tires, either. R-DOTs are what, 40 wear rating? That tells me they are substantially stickier than street tires.

This year, we'll see Rs beating STs and, as Scott suggests, an adjustment will be made. I would suggest that an assessment is made after the first 1/3 of the season draws to a close. If another adjustment is called for, it would allow for spectacular finishes at the end of the season. Whattya think?
I agree with you in principle. Stock cars should be on "stock" tires too. The problem is, where does someone with a 1958 Austin Healy find a set of 1958 bias-ply tires? Or how fair is it that they guy with a Porsche GT3RS gets to run on it's "stock" tires, a set of 40 treadwear Pilot Sport Cups (the same R-comps I use for time trials!)?

So in principle, it's a grand idea. In practice, it's impossible to limit tires in stock class. We're actually lucky that we can at least limit them to DOT tires... not that there's much limiting going on. A V710 is basically a slick. But it's still better than needing a $4000 set of Goodyear race slicks to be competitive.

What would be far more interesting is if Nationals limited stock class tires by MSRP. No more than $100 per tire MSRP, and the tire must be available in say 5 popular sizes from the manufacturer. That not only levels the playing field (though I'm not sure what the poor GT3RS driver will do to find $100 tires in 305/30/19), but it causes a pricing war between the manufacturers to see who can sell the stickiest tire for cheap. Maybe someone will sell a set of R-comps for $100/ea. If that's the case, they'll sell a set to every autocrosser in the nation, and we'll all be able to afford to go racing on R's.

[jim.gandy]

There is a human-nature element that comes into play here. You cannot expect the "ST crowd" to complain like the R folks did, because the ST factor is a deviation from national rules and from quite a few years of local tradition. Implementing an ST factor, like we did three years ago, is a "favor" to ST folks and they know it (I'm one).

The R folks have the weight of the rules behind them. Their goal may have been to get the handicap reduced, but part of their argument was "we shouldn't be doing this in the first place, it's not in the rules." That's a substantial hurdle to get over. The only thing in the entire rule book that even remotely references what we're doing is a single sentence in section 1.1, "Regions should use classing structures that are best for the development of their programs." If you're an R supporter, that single sentence is a pretty thin justification of an ST factor.

In short, ST people can't really jump up and down and holler "we're being screwed" the way R people can. So, basing the selection of the factor on the amount of noise being generated by the two sides isn't, in my opinion, the way to ensure the fairness of the number.

And that's another reason I'm an advocate of testing.

[MikeK]

Someone at one of the meetings recently pointed out that with the new ST factor, our region will effectively have 3 levels that a new autocrosser can compete at:

First is novice, where they don't have to worry about classes or modifications.

Next is racing in a real class using street tires, where they will only be competitive against other people on the same tires, but it will still be a cheap way to get into the competition.

Then finally, if they decide to get serious about winning at autocross and want to spend more, they can get race tires and try to be competitive at the highest levels.

I actually think this is a good system, to ease people into the sport over several seasons. I know that if there was no T factor in my first few years it would have been very discouraging, I don't know of many people who would be prepared to spend the money for race tires after only their first year or two of autox. I was on my original all season tires for most of my first year!

In any case, one of the loudest voices for changing the factor was Randy, who is in for a shock this year when Vic/Renee drive their new STi in AS on race tires. I predict that next year there will be an AWD or turbo handicap factor :p

[jim.gandy]

I apologize for being out of the flow of the thread, but I do want to comment on the idea that the real Street Tire Handicap Factor, in a perfect world, would be different for high-powered cars than low-powered ones.

Scott, I'm having trouble understanding the argument you're making. If you use a chalkboard or something and draw up a simple example --say a 90-degree turn leading onto a straight -- and then plot some typical example pairs -- say an R-tired Corvette vs an ST Vette, and an R Miata vs an ST Miata -- it seems to me that the dynamics are pretty much the same for both pairs. All four cars corner to their g-limit (higher for R tires), all four cars transition from cornering to straight-line acceleration (with "hook-up" coming sooner for R tires), and all four cars end up accelerating at their maximum (which is independent of tire type). At any given point on the diagram, the ST cars are slower than their R counterparts, even far down the straight (because the ST cars are slower at the start of the straight and can never "catch up"). There is no place on the diagram where the R cars don't have an advantage over the ST cars (we're not looking at braking). Even though the transition from cornering to full acceleration takes longer for the high-powered cars, the R Vette still has an advantage over the ST Vette at every point, just as the R Miata has an advantage at every point over the ST Miata. So far, I'm not seeing how the difference in the source of the advantage in one portion of the diagram then leads to a significant difference in the amount of the overall advantage.

I guess this may be your statement where I'm hung up: "The high powered car has to use the straights to press its advantage over the cars that are cornering more quickly, and in doing so it can take more advantage of the race tires than the lower powered cars." Something in there has me confused. Maybe it's something about "the high powered car...(on) race tires" working against "cars that are cornering more quickly."

Is my problem that my analysis is based on Vette vs Vette, Miata vs Miata? Your statement seems to indicate you're thinking more along the lines of Vette vs S2000, maybe?

Help me understand. Thanks.

[jim.gandy]

Maybe I've been around too long...

I was there when this whole mess started. I experienced the transitions from real street tires (70 and 80 series steel-belted radials) to low-profile tires (Phoenix Stahlflex, BF Goodrich T/A), to tall soft-compound tires (Yokohama A001-R), to low-profile soft-compound tires (Yokohama A008-R), yada yada, and now we've got ultra-low profile, ultra-sticky tires, really just racing slicks, masquerading as "street tires." Is there an end in sight? Is there something beyond the ultimate tire -- single-event stickies, good for just three runs? How about one-run tires? Anybody want to go there? To quote Jim Carey in "The Mask," "Somebody STOP me!"

The means to put an end to the madness is in the National rule book and has been there for decades. Rule 13.3.A, the Stock Category Tire Exclusion List. Once upon a time, there were years when perhaps as many as a half-dozen tires were banned from Stock (and Street Prepared, rule 15.3). Why is the Exclusion List no longer used? I'd like to think it's NOT because (a) the Solo Events Board lacks courage/wisdom, and (b) who is the sponsor of the Solo Nationals? Somebody tell me the real reason, please.

In my opinion, the fact that some cars come from the factory with R tires is too thin a basis for not using the Exclusion List. A simple change in the wording of 13.3 would do the trick. And you can color me callous, but I would shed no tears if the purchaser of new Porsche GT-3RS had to buy a new set of tires before he entered a Stock or Street Prepared Solo class.

[Dean]

Unless somebody has found significant fault with my Nationals data, I continue to believe that is the best data we have or can have without bringing those cars and drivers to Reno for a weekend. Any local comparison is going to have way to many variables to provide statistically significant data. Heck, the sample sizes from the national data are questionable from a statistical perspective and the preparation rule difference adds even more question to the validity, but anything we do locally will have many more inconsistencies as well as many of the ones at nationals.

Yes, R cars carry exit speed all the way down the straight, but unless the car can actually overpower the driven wheels all the way down the straight, they are just using past gains, not making new ones. The largest portion of their advantage is seen when they can use the additional traction. I don't think x% better traction translates to x% better exit speed. It is likely proportional, but not 1:1 IMHO.

I would also contend that T tires can often operate at higher slip angles as compared to Rs that tend to stick until they break loose in a big way. This can be quite an advantage at corner exit as well as permitting a driver to more easily get more from the tire.

[Kevin M]

Yes, R cars carry exit speed all the way down the straight, but unless the car can actually overpower the driven wheels all the way down tyhe straight, they are just using past gains, not making new ones. The largest portion of their advantage is seen when they can use the additional traction. I don't think x% better traction translates to x% better exit speed. It is likely proportional, but not 1:1 IMHO.

Bingo. As low-powered cars can rarely break traction on good street tires, the ST factor gives them a huge advantage entering straights compared to cars that can use more throttle when equipped with R tires. This advantage is negated by the advantages in braking and cornering of the R tires.

[jim.gandy]

Kevin, Dean --

I have two points:

First, as I said I don't care where the R car's advantage comes from, the fact is that the R car is faster at every point of the straight (because it started the straight faster). The longer the straight, the more the advantage, even though there's no appreciable difference in the physics once the tires have hooked up. The conclusion I make is that the R car is gaining time at almost every point on the course, that is, the advantage gained in the corner lasts all the way down the following straight.

Second, I beg to differ: a low-power car does break traction in almost every corner. Even if it lacks the power to break traction longitudinally, having broken traction laterally in the corner is enough -- tires can only do so much (remember the friction circle). I'll keep an open mind, but you'll have to work to convince me that an ST car has an "advantage" anywhere on any course. The only point I will concede is that R tires can break away more abruptly, making them more difficult for the inexperienced driver to master. But, our discussion and conclusions have to be based on apples-to-apples/good drivers in all cars.

[sperry]

Kevin, Dean --

I have two points:

First, as I said I don't care where the R car's advantage comes from, the fact is that the R car is faster at every point of the straight (because it started the straight faster). The longer the straight, the more the advantage, even though there's no appreciable difference in the physics once the tires have hooked up. The conclusion I make is that the R car is gaining time at almost every point on the course, that is, the advantage gained in the corner lasts all the way down the following straight.

Second, I beg to differ: a low-power car does break traction in almost every corner. Even if it lacks the power to break traction longitudinally, having broken traction laterally in the corner is enough -- tires can only do so much (remember the friction circle). I'll keep an open mind, but you'll have to work to convince me that an ST car has an "advantage" anywhere on any course. The only point I will concede is that R tires can break away more abruptly, making them more difficult for the inexperienced driver to master. But, our discussion and conclusions have to be based on apples-to-apples/good drivers in all cars.
Here's the simplest version I can come up with:

A low power car looses proportionally less time by running on street tires than a high powered car does. Therefore, the ST PAX helps low power cars more than it helps high power cars. The situation of the RT Vette vs. the ST S2000 is an ideal example of the phenomenon. The RT Vette is in trouble 'cause the ST S2000 has a bunch of numerical help, and the Vette can't necessarily go to ST itself to try to level the playing field.

The flaw in applying the same ST PAX is to all types of cars is not very large in my opinion, we just need to pick a number such that the majority of people don't feel like they're getting shorted. Personally, I think the ST PAX factor should reflect the greatest gap between RT and ST performance, which is on the high horsepower cars on fast courses. Since we've already made the policy that the ST PAX factor should favor race tires slightly, that situation is our baseline in my opinion. If a Z06 on RT is slightly faster than a Z06 on ST on the same course, the number is as fair as we can make it w/o going crazy trying to figure out a "real" set of numbers based on extensive testing (a process that I believe is impossible to do).

[Dean]

I'll keep an open mind, but you'll have to work to convince me that an ST car has an "advantage" anywhere on any course. I am not saying a ST car has an advantage at any point, anywhere on a course. What I am saying is that the majority of the advantage comes from when an R car is using the additional traction, not when it isn't.

Take a 100' straight into a U turn and back the 100'. Only if the car can break traction on T tires does R get an advantage from the start. Big advantage while turning, Some advantage while braking and accelerating assuming a perfect driver trail braking and accelerating and unwinding out of the turn. Smaller still gains on the second straight.

Now take a pure skid pad with the lights across the circle so all acceleration and braking are untimed and moot. The R advantage is in play 100% of the time.

Assuming the 2 courses are identical in time for the R car on the "optimal" path, I am alleging that the delta in times will be higher on the skid pad. Put another way, the T car will be slower on the skid pad than the U turn.

As an extension, I would allege that the a higher HP car that can exceed the traction of the T tire in a straight line for any length of time will have a greater advantage over one that cannot. The only point I will concede is that R tires can break away more abruptly, making them more difficult for the inexperienced driver to master. But, our discussion and conclusions have to be based on apples-to-apples/good drivers in all cars.This is part of the basis for my argument why any local testing is frivolous. With minor exceptions from our Sac visitors, we do not have the greatest drivers much less optimally setup cars in our region to do reliable testing with.

[dknv]

...This is part of the basis for my argument why any local testing is frivolous. With minor exceptions from our Sac visitors, we do not have the greatest drivers much less optimally setup cars in our region to do reliable testing with.Heartily agree, as well as with the point that, statistically, even data from Nationals is not significant enough due to numbers of reasons.... I'd be happy to share some examples from 2007 Nationals.

...The flaw in applying the same ST PAX is to all types of cars is not very large in my opinion, we just need to pick a number such that the majority of people don't feel like they're getting shorted. Personally, I think the ST PAX factor should reflect the greatest gap between RT and ST performance, which is on the high horsepower cars on fast courses. Since we've already made the policy that the ST PAX factor should favor race tires slightly, that situation is our baseline in my opinion. I've thought this as well (the handicap factor would not be the same for all cars/classes).

One thing we haven't talked about yet, is the use of data acquisition to prove out some of the theories being discussed. I have a MaxQData: (Measures key parameters such as lateral and longitudinal acceleration, speed, and horsepower. Timings accurate to hundredths of a second.)
Scott has something fancier. Dean, I think you have something as well.
Thoughts about doing this?

[sperry]

Heartily agree, as well as with the point that, statistically, even data from Nationals is not significant enough due to numbers of reasons.... I'd be happy to share some examples from 2007 Nationals.

I've thought this as well (the handicap factor would not be the same for all cars/classes).

One thing we haven't talked about yet, is the use of data acquisition to prove out some of the theories being discussed. I have a MaxQData: (Measures key parameters such as lateral and longitudinal acceleration, speed, and horsepower. Timings accurate to hundredths of a second.)
Scott has something fancier. Dean, I think you have something as well.
Thoughts about doing this?
My RacePak doesn't like to work very well for autocross. You need to be traveling faster than 30mph according to the GPS before it even switches on (the idea being it doesn't log you while you're in the pits, but automatically switches on once you hit the track) so you tend to miss the beginning of every run.

Also, I have no plans on spending the money for R-comps for autocross. My tire budget goes to time trials tires, and they're not great R-tires for autocross.

[Dean]

Heartily agree, as well as with the point that, statistically, even data from Nationals is not significant enough due to numbers of reasons.... I'd be happy to share some examples from 2007 Nationals.

I've thought this as well (the handicap factor would not be the same for all cars/classes).

One thing we haven't talked about yet, is the use of data acquisition to prove out some of the theories being discussed. I have a MaxQData: (Measures key parameters such as lateral and longitudinal acceleration, speed, and horsepower. Timings accurate to hundredths of a second.)
Scott has something fancier. Dean, I think you have something as well.
Thoughts about doing this?If you have something specific about the data I selected from nationals, please do share.

I have a G-tech R/Pro, but am confused when you appeared to agree with my assertion that local data collection is frivolous. :confused:

[Kevin M]

If you have something specific about the data I selected from nationals, please do share.

I have a G-tech R/Pro, but am confused when you appeared to agree with my assertion that local data collection is frivolous. :confused:

Datalogging could give us a number for how much greater the acceleration, braking and cornering forces are on race tires in a given car and setup. But then there's a big leap from that data to quantifying those advantages on a given course.

[Dean]

The April '08 SportsCar has a marginally interesting T vs. R tire test.

Their sample is way to small and they only compared 2 tires on a single car, so not statistically significant in my opinion.

One thing that is clear as I previously discussed is that the car setup for the two tires is significantly different. The generated a .2 second change for the T with only a front sway bar change that actually hurt R performance. I honestly think if they had used a ST/SP prepared car they could have optimized the T car better and closed the gap further.

I know somebody will ask, so they appear to have ended up with a 1.7 second difference over a 40 second course which is 2.55 seconds per 60 or .959. But again, there testing is minimal and miles form conclusive or even suggestive of a statistically significant test in my opinion.

The tire size test was equally less than useful as they failed to provide data on the weight of the wheels and tires in the two setups much less what they did to optimize teh vehicle setup if any they did for each.

[as197f12518]

So a couple things that I see absent from this discussion. How about the fact that equal access to the "best" street tires for all cars does not exist? How do we handle that? Like it or not, at least everyone has access to Hoosiers or Kumho R comps.

Dean, I really disagree with your comment that they should have used an ST or SP for testing. Half the people in this thread want stock classes to be forced back onto street tires only. To me the fact that they tested on a stock car is far more relevant than if they HAD used an ST/SP car.

It is clear that the ST/R comp discussion will rage as long as the class structure forces everyone to race in the same class for points. I am glad that there seems to be an understanding that our local rules need to support the national rules. I personally feel that street tire cars should not have to race against R comp cars. And I will never support the notion of "if you don't like it, race on street tires", (see my first comment in this post) My family and I race national level events, where we have to race on R comps. One should practice the same way that you race, wouldn't you all agree?;)

I hear so much discussion about the street tire pax and the so called "high altitude issue". All of this comes from one source. The desire to be number one in the overall PAX. Perhaps SCCA has shown great wisdom in not recognizing the use of PAX factors in solo.

I'll make you guys a deal. Someone pony up for the Falken RT615's for my A stock car and I'll supply a fresh set of 710's. We'll test at Stead and I'll do the driving and car tuning. Put Jim Gandy with me as a second driver, he's fast, and drives street tire all the time. The car is fast, you guys know that. It has double adjustable shocks all the way around and a fully adjustable front sway bar. It is built to the limits of the national rules for stock class. I can dial it in for either tire type. We'll go run and test and see where we come out. Any takers?

Jay Williams
F125 #79
AS #197

[Dean]

So a couple things that I see absent from this discussion. How about the fact that equal access to the "best" street tires for all cars does not exist? How do we handle that? Like it or not, at least everyone has access to Hoosiers or Kumho R comps.Huh? There is not a single Hoosier or 710 255/40-17 and at least 2 T choices. Optimal tire sizes are always an issue R or T. Hoosier and Khumo don't even match 1:1 in sizing, so you don't have the optimal choice in Rs either.Dean, I really disagree with your comment that they should have used an ST or SP for testing. Half the people in this thread want stock classes to be forced back onto street tires only. To me the fact that they tested on a stock car is far more relevant than if they HAD used an ST/SP car.I am one of those who feel all S cars should run on T tires, pure stock suspension, etc. Stock should be the way you drove it off the showroom floor. $1000 shocks and such are silly in a "stock" class, but that is for another thread.

The fact that they needed to change front bars to make the T tire perform just shows that the setups are not the same. Again, they don't give any useful details as to what they tried from an alignment or tire pressure perspective.

My point remains that the article is largely useless as is any testing you can do with one car on one course in the timespan of a day. If you feel otherwise Jay, lets go to a T factor of .96 based solely on this article! :)

It is clear that the ST/R comp discussion will rage as long as the class structure forces everyone to race in the same class for points. I am glad that there seems to be an understanding that our local rules need to support the national rules. [...] My family and I race national level events, where we have to race on R comps. One should practice the same way that you race, wouldn't you all agree?;)I think you mistake the goals of this club. IMHO we aim to have fun and keep as many members as reasonably happy and involved as possible, not to follow national rules. Our Open and L running together, 2 driver, Novice, RNP and Street Tire rules make that pretty clear.

You are welcome to "practice" on whatever you want. If it is really practice, why do you care what other drivers are doing? You should be focused on your driving and your car setup, not other drivers. If it is really "practice", RNP twice a day all season long as we all know the best way to go faster is by investment in seattime for the driver. :rolleyes:

[TracDaz]

I've just finished reading the Street to Race tire comparison in the 4/08 Sportscar magazine. I found the results to strongly demonstrate that our 2008 Reno tire handicap is wrong. The results are a culmination of many hours of a national-level driver driving a currently competitive B Stock car (Mazda RX-8) using both race and street tires. They even used different adjustments to find the best times between the two tires.

The difference over a 40 second run was 1.7 seconds. Race tire = 40.00; Street tire = 41.70. No matter how that's sliced, it represents a street tire to be just 95.8% of what a race tire is. We think it's 97.5%, but we've never actually tested it. I think the test is a significant new benchmark.

Don't kid yourself that this doesn't represent substantially more statistically relevent data than what we're using now. Our Street Tire index seems to have started with real data and is now adjusted with more emphasis on who argues longest or loudest.

I agree with Mike K that Vic and Renee in an STI on race tires will whoop anyone in AS unless they're in another STI on race tires. Will STIs on race tires become the next to be handicapped? :eek:

[Kevin M]

It's still only one car and (According to your summary) one driver. I personally think our old 2 seconds per 60 handicap is about right; however, I am not too bothered by reducing it this year. Nevermind that it may make the difference between top 10 PAX finishes or not for me- I won't complain about the rules hurting me until I can honestly say that I'm skilled enough to trophy at National level events. Until then, I'm going to blame my own mistakes and not harp on and on about cars, rules, indexing, classing etc.

[TracDaz]

I agree this issue seems like splitting hairs. Those hairs, however, are equal to the fractions of seconds these class championships are decided by when there's viable and spirited competition.

According to our newest ruling, for my 60 second lap on street tires, a fellow competitor will only have to run a 58.5 second lap on racing tires to tie me. That's .42 seconds slower than the handicap provided for in 2006 and 2007. It's also .95 seconds slower than what the comparison test findings are in the recent Sportscar article.

It will be interesting to see how it all unfolds.

[Kevin M]

It will be interesting to see how it all unfolds.

We all know how it ends. Somebody wins PAX and/or a top class witha close finish, and we spend another offseason arguing about how unfair PAX and ST modifiers are- regardless of who actually gets that controversial win and what setup he/she is driving. :D

[as197f12518]

Which brings us back to rethinking running street tires and R comps together in the same classes. Those of us on R comps suggested this, we were told NO. Fine, I respect that decision, but then you need to understand that those who run R comps will continue to be upset. I want to see local data used to set the factor, and I want some assurances that the factor is correcting only the differences in the tire, not driver differences or car prep differences. Here's an example for you. John and Patty Evans 350Z. That car is not a real strong car in B stock nationally. Why, you ask? Well, you can't dial any front negative camber into the car. The R comps need it, the ST tires don't. Now you have a car using the best ST tire that wins the class using the PAX correction. Put that car on R comps and put it up against the RX8 and the results change completely. This tells me that the factor is allowing a correction for more than just the tire difference. And thats just not right. I've offered to help develop information so that we can set a factor based on local results, local cars, and local drivers. And since it would be developed at Stead that eliminates the altitude issue as well.

I think Jim Gandy's comments sum up how those of us who campaign cars on R comps feel about this whole situation. I consider you guys friends and I don't like the fact that this issue has the potential to cause a great deal of hard feelings and possibly divide the region. We may be starting down a path that none of really want to take...:(

As Kevin mentioned, all this is relates back to the overall PAX championship. Perhaps a return to class championships only if it will help to quell this issue. Or keep the classes combined for points but have a seperate PAX championship for R comps and ST? I can't help but feel that some want R comps to die. I am fine with the idea that some wish race on ST tires, but I will continue to speak loudly when I feel the ST Factor gives favor to ST tires over R comps. And for the record I feel the 2008 factor is reasonable to both sides.

Respectfully,

Jay

p.s. Dean , ST tires in the current hot brands do not exist in 275/40R17's. The only one is the Falken RT615. And while a 255/40R17
R comp may not exist, 245/40's and 245/45R17's do. And thats still bigger than what a stock STI comes with from the factory. So while you can get bigger than stock tires in R comps, I can't even get the stock size ST tire in the Bridgestone, Hankook or Yoke. Where's the fairness there? If you are speaking of your own SM car, you are not limited to stock wheel width, or diameter. You can flare the car, wider wheels, bigger diameter are all available to you. These options are not allowed for anyone running in stock classes.

[Kevin M]

Which brings us back to rethinking running street tires and R comps together in the same classes. Those of us on R comps suggested this, we were told NO. Fine, I respect that decision, but then you need to understand that those who run R comps will continue to be upset.
Street tire allowances are the single biggest factor in the growth of the region IMO Jay. Nobody wants to throw that away because a few members are "upset."

I want to see local data used to set the factor, and I want some assurances that the factor is correcting only the differences in the tire, not driver differences or car prep differences. Here's an example for you. John and Patty Evans 350Z. That car is not a real strong car in B stock nationally. Why, you ask? Well, you can't dial any front negative camber into the car. The R comps need it, the ST tires don't. Now you have a car using the best ST tire that wins the class using the PAX correction. Put that car on R comps and put it up against the RX8 and the results change completely. This tells me that the factor is allowing a correction for more than just the tire difference. And thats just not right. I've offered to help develop information so that we can set a factor based on local results, local cars, and local drivers. And since it would be developed at Stead that eliminates the altitude issue as well.
The short answer is that this is impossible Jay. Not only do we have a very, very small number of top-level drivers, but we have even fewer top-level prepped cars. Additionally, the balances of each change each year as people get new cars and/or change classes. Trying to adjust locally means we'll be going through the same huge effort every season, only to have it be obsolote before it's even implemented the following year.


I think Jim Gandy's comments sum up how those of us who campaign cars on R comps feel about this whole situation. I consider you guys friends and I don't like the fact that this issue has the potential to cause a great deal of hard feelings and possibly divide the region. We may be starting down a path that none of really want to take...:(
I thought the opposite actually. Towards the end of winter, everybody seemed to decide that reconciling and accepting compromise was more valuable to everyone than outright "victory" for their proposals. Hence the increase in ST factor andkeeping everyone lumped together.

As Kevin mentioned, all this is relates back to the overall PAX championship. Perhaps a return to class championships only if it will help to quell this issue. Or keep the classes combined for points but have a seperate PAX championship for R comps and ST?
I think that's a constructive idea. I would be open to the idea of seperate PAX standings.

I can't help but feel that some want R comps to die.
I can't say I feel this is true for anybody at all. I personally would much rather be running on Hoosiers than Bridgestones, but I can't afford it. Last I checked, one of the big points in favor of Solo in the first place is high-level competition that doesn't require a huge budget. I think being able to win your class on an $800 tire budget instead of $2000 most certainly follows that philospophy. On the other hand, you know that if money wasn't a factor, than we'd all be on R compounds that last a day. Nobody on street tires wants to take away another driver's option to run, and be evenly matched, on R compounds. In fact, most of us believe the street tire factor, even before this year's adjustment, slightly favors raece tires up here. However, we recognize that it should do so, which is why you don't hear any ST proponents campaigning to have it reduced.
So what the street tire factor is intended to do is make it as even as can possibly be for each driver to have a real choice between street tires and R tires. There will never, ever be a day when an autocross season is run that there is such absolute undeniable parity that nobody has any complaints whatsoever. Even if we eliminated the street tire rule, or made the factor so lousy that only the best ST drivers could beat the worst RT drivers, there would still be people who thought they should have been winning, and will blame rules when they don't. Our system obviosuly isn't that perfect, but the vast majority of the region's members seem to think that it's as close as it will ever get.

I am fine with the idea that some wish race on ST tires, but I will continue to speak loudly when I feel the ST Factor gives favor to ST tires over R comps. And for the record I feel the 2008 factor is reasonable to both sides.
I am glad to hear you are somewhat happy with the new factor Jay. We're never going to make very many drivers (that have an opinion one way or the other anyway) totally happy; if we've made the majority almost happy however, we've succeeded.

[jim.gandy]

Once again, thanks to everyone who is keeping this thread going. Our region needs to have this discussion year-round, not just at Supp-changing time.

There's more about R vs. ST tires in the April Sports Car besides the tire test. If you haven't already, take time to read the "Leaving the Line" column on page 62. Paul Brown, a very experienced Soloist, gives a good demonstration of just how difficult this topic is. He lays out some historical perspective (it's always good to reflect on how we got to where we are today), and then tosses around a few pros and cons -- just like we're doing in this forum. But in his final paragraph, there are two things I have to comment on.

First, he says "the last alternative I can think of..." implying he's covered all the bases -- but he fails to mention the concept of "integration using a handicap factor," the thing Reno Region is experimenting with. Why the oversight? Draw your own conclusion, but I think it's because using a factor is such a radical idea that most people wouldn't take it seriously, even though Soloists all over the country are using EXACTLY the same concept (it's called PAX) all the time without complaint (except for us high altitude folks, I know).

And second, please note the last sentence of Paul's column. "Looks like a recipe for steadily shrinking entries, which is probably not the ultimate goal." He was referring to the concept of a "spec" tire model in Stock category, but look at his logic. Isn't that almost the same situation the SCCA (nationwide) has today? Joe Blow starts coming to autocrosses with his stock Kia Rio (or Miata, or Corvette) on everyday Les Schwab/Sears/Pick-n-Pull tires, and he very quickly sees that in order to have a chance, he must buy one of a very limited number of R tires -- and probably a set of wheels, too, for practical reasons. Paul Brown uses the words, "...what about those local people who make up a large portion of the entry list?" Although he's talking about National Tours, Pros, and Topeka, doesn't the same logic apply to individual regional events? I think Paul's logic is great, it's just that his personal perspective is focused on upper-level events.

Here's my point: Solo is the most basic, most entry-level motorsport -- it's a gateway. All you have to do to participate is pay the entry fee. NO extra equipment is required (we'll loan you the helmet). What a wonderful concept! Not even karting, motorcycles or your local roundy-round can compete with that. It's a great way to introduce people to the whole range of motorsports. So, why does Solo (nationally) think it's necessary to place this whole R-tire hurdle in front of newbies? How can that possibly contribute to the growth of the sport of Solo, the growth of individual regions, and the growth of the SCCA?

This is a moot point where events are fully-subscribed. Most San Francisco Region Solo events have more entries that can comfortably be accommodated. Ditto with Tours, Pros, and the Topeka championships. So of course this Street Tire thing is a non-issue at those events. But wherever growth is still a priority (and that's the large majority of regions), we should lower the bar every chance we get, not raise it. And remember, nationally the SCCA's membership has dropped over 10 percent in recent years.

One last comment. Paul Brown takes a look back at the history of R-tire development. We all know where we are today. Anyone care to look ten years into the future? Please tell me what's going to keep "single-run" tires out of Solo. If you have the money, you can do it today. Is that where we want our sport to go?

My thanks again to everyone who is participating in this discussion. Keep it going! :)

[Skyhorse]

As someone who likes weird old things I think I am at a disadvantage when it comes to street tires for my 72 240Z (I hope to fun it a few times this year in ES) when I look at tire racks site it looks like the best street tire that will fit on a 14x5.5 rim has a 280 tread wear rating. Cars that run 15 inch or better wheels in stock class seem to have many more options. This is nothing new to me as all of my vintage motocross bikes run 18 inch rear tires and modern bikes have 19’s . The Z will be running a set of closeout kumho 185/55/14 V700 R’s

[Kevin M]

Scott, you're in FSP- you can get a set of 15" or 16" wheels quite cheap that will enable many, many tire choices for you in both flavors.

[Skyhorse]

Kevin thanks for the reply but I am one of those people who have to collect things that start with D, Dodges and Datsuns mainly my 510 is an FSP car but the 240Z I have will be ES after I remove all the cool things I have put on it over the years :D

[Kevin M]

Gotcha.

[Dean]

As someone who likes weird old things I think I am at a disadvantage when it comes to street tires for my 72 240Z (I hope to fun it a few times this year in ES) when I look at tire racks site it looks like the best street tire that will fit on a 14x5.5 rim has a 280 tread wear rating. Cars that run 15 inch or better wheels in stock class seem to have many more options. This is nothing new to me as all of my vintage motocross bikes run 18 inch rear tires and modern bikes have 19’s . The Z will be running a set of closeout kumho 185/55/14 V700 R’s There is a 195/60-14 Falken Azenis 615.

[dknv]

K. First of all, Mark and I race with Jason, the author of the tire test article and owner of that car. See the 2nd paragraph in his article, "As with any test, there are a number of variables that can affect the outcome: course layout, car setup and, of course, the driver all play determining factors."

Jason tells me the test course was very transition-heavy, and the street tires could not carry speed in the transitions that the race tires can. Add to this, that while they got the most out of each setup with the tools/parts they had to work with, with more time and bigger setup changes it is likely they could have gotten quicker on the ST tire. These test results corroborates what Dean has pointed out before, you have to tune to the tire to get the most out of them. How possible will this be (tuning, parts, setup time) to accomplish locally? And if we tested at Stead, but left this stone unturned we'll still end up with questions and suspicion about the accuracy of the results. Bottom line, there is not enough evidence from this article to validate a 'more-correct' value for a street tire index.

There were a couple of other points in this article that interested me -- 1) the shaved RE01R's did not provide a time advantage (over unshaved); and 2) the lighter wheels did not provide an advantage for the street tires, but did for the race tires. Did anyone in the region shave their RE01R's last year?

[sperry]

K. First of all, Mark and I race with Jason, the author of the tire test article and owner of that car. See the 2nd paragraph in his article, "As with any test, there are a number of variables that can affect the outcome: course layout, car setup and, of course, the driver all play determining factors."

Jason tells me the test course was very transition-heavy, and the street tires could not carry speed in the transitions that the race tires can. Add to this, that while they got the most out of each setup with the tools/parts they had to work with, with more time and bigger setup changes it is likely they could have gotten quicker on the ST tire. These test results corroborates what Dean has pointed out before, you have to tune to the tire to get the most out of them. How possible will this be (tuning, parts, setup time) to accomplish locally? And if we tested at Stead, but left this stone unturned we'll still end up with questions and suspicion about the accuracy of the results. Bottom line, there is not enough evidence from this article to validate a 'more-correct' value for a street tire index.

There were a couple of other points in this article that interested me -- 1) the shaved RE01R's did not provide a time advantage (over unshaved); and 2) the lighter wheels did not provide an advantage for the street tires, but did for the race tires. Did anyone in the region shave their RE01R's last year?
I don't think anyone but Dean have done the shaved ST route, and that was just 'cause he was going to Nat'l Tours that season in STX.

Pretty much everyone in Reno that's serious enough about autocross to shave their street tires are serious enough to just go to race tires. Except Dean, he's cheap. :p

[Joeyy]

Just purchased the tires for the kart. I'm going with the Vega Yellows. Thought about MG greens but I think Vegas won in Topeka. Hope they like the surface out at Stead.

[Kevin M]

So, you picked race tires for the kart over race tires? :p

[Joeyy]

So, you picked race tires for the kart over race tires? :p

Yep, probably the wrong thread but I did have to choose between MG greens or the Vega yellows. What do you expect from a nOOb?

[jim.gandy]

Cal Club Region (Los Angeles) is using a Street Tire Handicap Factor, although in a significantly different way than we are. Their number for this year is .980.

Here's an excerpt from Cal Club's Solo Supps:

STREET TIRE (SK1 & SK2):
(a) Purpose: To encourage drivers who compete in CSCC SOLO events to race
on the same tires they use on the street. (Also referred to as "Street
Stock.")
(b) Eligibility - SK1 & SK2: Any Stock Class legal car, prepared in accordance
with Para. 13 of the 2003 SCCA National SOLO II Rulebook, with the
exception that all of the tires mounted on the car must have a TREADWEAR
number of 140 or higher molded by the manufacturer on the sidewall.
(c) Indexing: Each car competing in the Street Stock class will be indexed in
accordance with the PAX (performance) index. For the sole purpose of
team championship point calculation, times shall also receive an additional
"Street Tire" index (SK) which is listed in Appendix C.
(d) Separate classes:
1) SK1 consists of SS, AS, BS and FS.
2) SK2 consists of CS, DS, ES, GS and HS.
3) Men and Ladies shall compete in separate classes.
(e) Registration: Each Street Stock competitor shall, in addition to listing SK1
or SK2 in the Class block, shall list the class he/she would normally run in
(e.g. if a competitor normally runs CS, he would write SK2 in the Class
block and CS in the Indexed Class block).
(f) Results: Every Street Stock competitor will have their corrected times
listed, then the PAX index for their car, followed by the best 'indexed' time,
arrived at by multiplying their best corrected time by the PAX index number
for the cars class and also the SK index from Appendix C. [Example
Calculation: (Best Time) X (Class Index) X (Street Tire Index) = Final
Indexed Time]
APPENDIX C lists the SK1 and SK2 multiplier as 0.980

The above info comes from Philip Royle, editor of Sports Car magazine and a Cal Club Solo competitor. He also says that the SK factor is used when calculating the SK1 and SK2 competitors' overall PAX standings, although the rules excerpt he sent doesn't directly say that. Of the idea of using the factor, he says, "generally, everyone here is happy with it."

On a different subject: Did you notice Rule d3 above? "Men and Ladies shall compete in separate classes." Can that be true? Is segregation of the sexes enforced in Cal Club? I've always thought that females had the option of Open or Ladies classes. I've never run across a rule like this one before. :eek:

[MattR]

So it limits it to stock cars only. It's good to see some other scoring schemes out there are working.

[MikeK]

In any case, one of the loudest voices for changing the factor was Randy, who is in for a shock this year when Vic/Renee drive their new STi in AS on race tires. I predict that next year there will be an AWD or turbo handicap factor :p

For the record, the motivation for this comment was to stir trouble. No malice was intended, Randy :)

[solonut]

For the record, the motivation for this comment was to stir trouble. No malice was intended, Randy :)
Randy has no trouble with it....he will just Armorall all their tires for them:rolleyes:

[as197f12518]

So I'll add a few more thoughts to the subject. If memory serves me correctly, Sac chapter uses a factor of .959 for street tires. As for the way they handle classes, street tire is a single class that runs during a run group. Street Tire is its own class with its own points. Points are awards for their class based on PAX order of finish. They are not mixed in with the regular classes for class points. They do compete for overall PAX using the ST PAX correction factor.

Sac's factor was developed using local data from several years of data. A recent review of the ST PAX shows that it is due for a revamp. Data has also shown that the factor should not be same across the board. To be really fair, it needs to vary across the classes, just like the standard PAX does. Basically what Rick's data found was that low power cars (ie HS) should get less correction for ST versus a Super Stock car. And while it was not acted on this year, I suspect changes will be made next year. Oh, and the data points toward stiffening the factors for all classes, not making it softer.

There are no complaints, no upset people, no hard feelings among people competing in Sac chapter events pertaining to street tires. The ST competitors have a class where they can all compete against each other. They are happy. And the regular class competitors don't have to worry about losing class points to a calculator. And they are happy. And even though Sac uses a much softer factor, ST tires do not dominate. The reason is that the ST competitors are mostly casual competitors who have truly stock cars. A few have put on stickier ST tires and tweaked the alignment a bit. But no one is running a fully prepped car, towing it in and then putting ST tires on it.

SFR uses a system somewhat like Cal Club. They have T1 & T2. T1 is for stock, T2 is for SP & SM cars. They compete in their own class for their own points. SFR does not have an overall PAX championship. They do not have a correction factor. There was a discussion several months ago where someone asked for a correction factor to be used on the overall PAX results so that ST drivers could compare how they did to R comp cars. They were told no, the reason was SFR saw no need to do so, they sited Sac and Reno and the fact that each region had different numbers. So does Cal Club. 3 regions, 3 different correction factors.

I think this discussion needs to end so that all of us can concentrate on racing. Why continue to beat on it, the board has made its decision for the year, its not going to change until next year. Continuing this does nothing but bring discontent and hard feelings to the surface. Personally I fear that if this does not die down for the season that it will create a rift within the membership. Nothing good will come of that.

[Skyhorse]

I seem to be having a hard time wrapping my mind around this whole tire debate. I thought the idea of racing and competition of any type is speed and controllability. I started out on ST last year and tore them up in a few months my R’s will go at least two seasons, so much for a cost debate. Remember this is supposed to be fun let’s not make it more difficult for new people to figure out. If something is limiting my ability to go faster I need to change the car or myself not the rules.

[sperry]

I seem to be having a hard time wrapping my mind around this whole tire debate. I thought the idea of racing and competition of any type is speed and controllability. I started out on ST last year and tore them up in a few months my R’s will go at least two seasons, so much for a cost debate. Remember this is supposed to be fun let’s not make it more difficult for new people to figure out. If something is limiting my ability to go faster I need to change the car or myself not the rules.
What sort of R tires are you running? Most people can't get more than half a season on the Hoosier A6's, and the V710's can't quite get to the end of a season either. Whereas the street tires (615's for example) get a full season of racing, plus daily street driving. Plus a set of streets are around half the cost of a set of R-comps.

[Skyhorse]

Closeout $100 Avon tech-RA’s +light car 1800 pounds +low horse power maybe 125 = good tire wear :)/ being slow has one advantage. last year I ran about 10 Reno and 4 Stockton weekends plus the Hoopa Hillclimb on the Avons and i dont see any reason they will not do the same this year. A 3500 pound car with 400 hp would be a totaly different story

[Kevin M]

So I'll add a few more thoughts to the subject. If memory serves me correctly, Sac chapter uses a factor of .959 for street tires. As for the way they handle classes, street tire is a single class that runs during a run group. Street Tire is its own class with its own points. Points are awards for their class based on PAX order of finish. They are not mixed in with the regular classes for class points. They do compete for overall PAX using the ST PAX correction factor.

A few years ago we did something like that. All street tire cars (outside of ST* classes) ran in their own run group as one class. By the end of the season, it was larger by far than the other 3, which caused logistical problems during events. As street tire usage has only increased since then, it's safe to say that we will not be returning to a segregated run group format for those who are on street tires. That class was also indexed using PAX + T (then N) handicap and also counted in overall PAX standings.

Sac's factor was developed using local data from several years of data. A recent review of the ST PAX shows that it is due for a revamp. Data has also shown that the factor should not be same across the board. To be really fair, it needs to vary across the classes, just like the standard PAX does. Basically what Rick's data found was that low power cars (ie HS) should get less correction for ST versus a Super Stock car. And while it was not acted on this year, I suspect changes will be made next year. Oh, and the data points toward stiffening the factors for all classes, not making it softer.

I don't think anybody on street tires would oppose the statement that .959 is too soft for street tires in any class. And while the suggestion that each class should have a varying ST factor is valid conceptually, nobody has the time or sufficient data to even begin breaking it down in that manner.

There are no complaints, no upset people, no hard feelings among people competing in Sac chapter events pertaining to street tires.
There are no complaints from ST drivers here either, except when it's suggested that we shouldn't be eligible for class and PAX awards without running R compounds.

The ST competitors have a class where they can all compete against each other. They are happy. And the regular class competitors don't have to worry about losing class points to a calculator. And they are happy.
From where I've been standing the last few years, losing to Dean, John Evans, Lucas and Mike K when they are on street tires is not getting beat by "a calculator." High finishes in this region by people on street tires don't happen by accident. They happen when good drivers have good days.

And even though Sac uses a much softer factor, ST tires do not dominate. The reason is that the ST competitors are mostly casual competitors who have truly stock cars. A few have put on stickier ST tires and tweaked the alignment a bit. But no one is running a fully prepped car, towing it in and then putting ST tires on it.
Which makes any data collected by them essentially irrelevant.

SFR uses a system somewhat like Cal Club. They have T1 & T2. T1 is for stock, T2 is for SP & SM cars. They compete in their own class for their own points. SFR does not have an overall PAX championship. They do not have a correction factor. There was a discussion several months ago where someone asked for a correction factor to be used on the overall PAX results so that ST drivers could compare how they did to R comp cars. They were told no, the reason was SFR saw no need to do so, they sited Sac and Reno and the fact that each region had different numbers. So does Cal Club. 3 regions, 3 different correction factors.
Very, very few people in this region are at all interested in modeling after SFR's Solo program. In fact, we've gained new members (I was under the impression your family was among this group) because we're not like SFR. SFR is how you do things when you have 100 national-level drivers and another 300 ready to race every event weekend; not when you barely scrape 100 total and barely a handful are looking for that level of competition.

I think this discussion needs to end so that all of us can concentrate on racing. Why continue to beat on it, the board has made its decision for the year, its not going to change until next year. Continuing this does nothing but bring discontent and hard feelings to the surface. Personally I fear that if this does not die down for the season that it will create a rift within the membership. Nothing good will come of that.
This is not a new argument Jay; it's been bouncing back and forth for at least the 4 years I've been doing this, and then some. In another year or two you'll be like everyone else- grumbling about what you see as incorrect, before you strap in and take your runs like everyone else. We know our system isn't perfect, but it's never going to be as long as membership keeps growing. The best we can hope for is what we have achieved, which is a roughly equal set of gripes from each of the various sides of the various issues that don't go away around here. The ST factor was tweaked this year, so essentially the argument was settled then as far as the Board and the active membershop is concerned. Now it's time to go out and see what happens, and see who's wheels are the squeakiest come next silly season.

[dknv]

Closeout $100 Avon tech-RA’s +light car 1800 pounds +low horse power maybe 125 = good tire wear :)/ Great experience with those tires!

There are also plenty of stories of drivers running Kumho V710's past 100 runs, albeit in sub-3000lb cars and with smooth drivers. Point being that R-comps can be stretched to last a season or more as well.

[sperry]

Great experience with those tires!

There are also plenty of stories of drivers running Kumho V710's past 100 runs, albeit in sub-3000lb cars and with smooth drivers. Point being that R-comps can be stretched to last a season or more as well.
I'm just surprised to hear that on a lightweight car, the Avons are somehow lasting longer than street tires! I can believe an 1800lb car can get lots of time out of even really soft tires, but I don't know how those soft tires are going to last longer than harder streets.

[Kevin M]

They don't. I used less than half the life on my RT615s in a full season on the Miata, and I was driving on them everyday. In fact, Ed Reichley got most of last season out of them too, and his car has triple the horsepower. Light cars just don't wear tires.

[solonut]

I ran the Avons last year, put 120-130 runs atleast on them....now they will be on wes friesens honda in csp....now this year I might run in STS2 or get Kumho 710's for ES.......

[Skyhorse]

The street tires I started out with are Sumitomo HTR-50z -160 tread wear. A low buck tire for sure, after a few runs the tread looked like a dirt bike tire that had been run thru rocks for a day it was still there just tortured looking .if they were on a street only car I bet they would hold up very well. A friend who builds legends cars said we should shave them and they would last better but I guess that is a whole different topic. It just seems to me that race tires just hold up better when pushed hard. I should also say that since I started running the Avon’s and did the coilovers etc. the 510 is strictly a trailer toad. Side note tirerack was the sole importer of the Avon’s and they no longer carry them guess I should have bought a spare :(

[Kevin M]

Those Sumitos aren't real good for much of anything Scott. They're black, round, and hold the car up... and I'm out of positive feedback about any tire similar to that. :p You should give a set of Extreme Performance summer tires like RT615s or Hankook RS2s. They'd last you 2 full seasons including street driving. They're sticky, responsive and will handle the beatings you give them at autocross.

[Skyhorse]

Did I mention I buy my tires at Harbor Freight?

[dsmith]

I got over 8,000 miles out of the last set of R-615s on the Miata, including 1.25 seasons of AutoX with triple drivers in the car, and the rest road miles. My last set of Hoosiers lasted one season and one weekend, with of course no road miles at all.

As Kevin said, the debating is over and it's time for racing. We all run with the rules we have and there's no changing them for this season. Who knows, this time next year we might be arguing Ethanol, Methanol, Gasoline instead of tires.

[Kevin M]

Who knows, this time next year we might be arguing Ethanol, Methanol, Gasoline instead of tires.

No... I'm gonna go with the street tire thing again next year. :cool:

[dknv]

No... I'm gonna go with the street tire thing again next year. :cool:I'm going to go with turbos/supercharges, vs. normally aspirated ...

[as197f12518]

I'm going to go with turbos/supercharges, vs. normally aspirated ...

I thought Mike K already claimed that one:p

Personally, I'd like a debate of electric hybrids vs. gassers vs. diesels....by the way what's my correction factor for the Motorhome?:eek: Its diesel, it has 6 street tires and seats 8. I should get all kinds of correction factors right?;) Plus it can tow a HS car around the course so I'd like HS to be my base factor. Any objections?

[AlexR]

IMO Keeping a healthy number of participants Should be Goal #1. IF others recall we have had at least one sunday where we were Asking (over the pa?) for people who wanted to do Run No Points in the afternoon session to suppliment the workers for the final sessions.

I recall that quite well as i tried to pre-pay for sunday Run no points and was told that we most likely wouldn't be doing them as people don't like staying late on sunday becuase of peeps doing Run no points, then on sunday i'm asked to run no points... (ticked me a lil , but i laughed it off)

Some people (not many at all) really don't care about being competitive, so we don't need to worry about if they are bummed out.

but for 95% (my guess) of racers who show up, they want to Win (to varying degrees) just look at how many people take out their spare tires!!!

So for me personally With out the street tire handicap I know i would have skipped a few more events last year. there was a few RallyX's i could have hit up over the Autocross events but i was trying to stay competitive with the points (i still got murdered :D good job John & Randy ) But I constantly felt right in the mix as i was often only .2 or .3 out

Having a system where people can switch back and Forth I feel is Awesome.

One comment that makes no sense to me what so ever, was the implying that if you are practicing for nationals that having street tired cars (with a handicap) in your class would be some sort of hindance ? huh? I would think giving them a bigger than fair handicap is going to be the best practice of all, Now you have to over someone with a better setup by your driving ability alone. in terms of becoming a better driver, what's better than that? (nothing!)

It boils back down to we all want to Win. (me too, i'm just too slow)

I got the new Sumitos HTR+ or what ever. I'm really really impressed with them. I only got 2 195/50/15 for my 93 subaru impreza (FWD 1.8L NA) haven't tracked em or anything yet, but Driving up 50 from sac i was able to double all the suggested semi speed signs with absolutely no tire noise or signs of being at the limit.


and finally, We could do more tire comparisons this year to give some local data to our results.

I have some RE0101s STI Rims, STI Size, Word is that Vic bought some 710s? if those are a 245, they hey, lets both do fun runs on afternoon on the other's set of tires, compare times. (I would probalby need to get Dean or Kevin to co-drive my car in the afternoon becuase i'm not constant enough yet, but Vic probably is)

I could throw you like $40 or something to (partialy) cover tire wear if you are at all remotely interested in trying this Vic.

Hell we could even drive 2 or 3 runs in a RNP session on tire set A, (in my car if you like) swap to set B on my car and run those. Same drivers, same car, same course, same time of day, only different tires...


:d nothing like a great argument ... er i mean dissussion to feel better about life eh?

["A" Stocker]

In Sacramento Our Street Tire Factor is .949, which worked pretty well up until this year. The guy who came up with the factor Rick Brown, noted that we need to look at giving every class their own ST Factor and that this number would possibly have to change yearly. As classes improve, tires improve, cars improve the ST Factor will have to be changed. As Jay stated in reality you are getting beat by the calculator and not necessarely a better driver or more prepped car.
Raw Time x PAX Factor x Street Tire Factor = Final Time
Raw Time x PAX Factor = Final Time (you have just been beaten by the calculator)
R-Comps are usually good for about 1.5 to 2 sec. on a 60 sec. course with a good driver and a fully prepped car over a good driver and street tires. The Street Tire Factor gets rid of that advantage, by using a calculator and not by better car prep or improved driving skills. The guy who has went out and prepped his car and worked on his drivnig skill is at a disadvantage before even unloading his car. This guy is already 2 sec. behind at the start line, because of a factor and a calculator, not because a better driver or better car prep. I didn't like the Street Tire Factor when it started in Sacramento and I really don't like it 4 or 5 yrs later. If you want to feel good improve your driving and improve your car, don't change the batteries in your calculator and look for a number to feel good. I also have the same feelings about the PAX Factor too.

[Jamin]

What a fascinating read. I'm not a member in your region, but I don't think two more cents will hurt this pile of loose change.

I stated in Solo II on a lark years ago. I raced on street tires in an unprepared stock car. I had fun. The "good" drivers were so far ahead of me anyway, really - what difference did it make if I was .959 or .985 closer to them? Everyone I brought inot he sport over the years faces the same hurdle: fixing the driver.

Once I got serious, I saw that I would need to run R comps to continue improving; I had reached a point as a driver where I would benifit from them and from bettering teh car setup, I did what I needed to to get them. I was on a budget that I would dare anyone to say they could beat in terms of being too broke to run R comps. I bough a set of used wheels off another car that shared my vehicles wheels size and offset but were lighter, and bought a couple sets of used S04 roadrace compounds. Not as good as A-series Hoosiers - but there are a number of steady sources for many sizez of used roadrace tires with 60-90% tread remaining. They got me through a couple of seasons. The national-level drivers still whooped me by so much that it wouldn't ahve mattered; but I managed to edge out one or two other "up and comers" who were also on R comps, which I couldn't have on streets. This justified the price of entry.

Autosports is ALWAYS a money sport, no matter how humble or grassroots the venue in question. If T classes are helping keep attendance up, great! I fail to see why the lack thereof - when novice classes exist - would hurt it though. I good driver on streets will demolish a newb on R comps regardless. I guess what i mean is - if being competitive is an issue for bringing in racers, the problem lies deeper than a T modifier! Start in novice classes, realize that it's going to take a lot of driver improvement to get you where you need to be, and that ultimately, to get to the top, you'll need to prep accordingly - and that might mean buying R comp rubber.

This is a great thread - my opinion shifted a bit back and forth over the course of reading it, a very good sign. But at the end of the day, someone who's put in the money and effort to prep their car to the rules' limit shouldn't ever lose to a calculator. That's just not right.

:shrug:

[Kevin M]

What a fascinating read. I'm not a member in your region, but I don't think two more cents will hurt this pile of loose change.

I stated in Solo II on a lark years ago. I raced on street tires in an unprepared stock car. I had fun. The "good" drivers were so far ahead of me anyway, really - what difference did it make if I was .959 or .985 closer to them? Everyone I brought inot he sport over the years faces the same hurdle: fixing the driver.

Once I got serious, I saw that I would need to run R comps to continue improving; I had reached a point as a driver where I would benifit from them and from bettering teh car setup, I did what I needed to to get them. I was on a budget that I would dare anyone to say they could beat in terms of being too broke to run R comps. I bough a set of used wheels off another car that shared my vehicles wheels size and offset but were lighter, and bought a couple sets of used S04 roadrace compounds. Not as good as A-series Hoosiers - but there are a number of steady sources for many sizez of used roadrace tires with 60-90% tread remaining. They got me through a couple of seasons. The national-level drivers still whooped me by so much that it wouldn't ahve mattered; but I managed to edge out one or two other "up and comers" who were also on R comps, which I couldn't have on streets. This justified the price of entry.

Autosports is ALWAYS a money sport, no matter how humble or grassroots the venue in question. If T classes are helping keep attendance up, great! I fail to see why the lack thereof - when novice classes exist - would hurt it though. I good driver on streets will demolish a newb on R comps regardless. I guess what i mean is - if being competitive is an issue for bringing in racers, the problem lies deeper than a T modifier! Start in novice classes, realize that it's going to take a lot of driver improvement to get you where you need to be, and that ultimately, to get to the top, you'll need to prep accordingly - and that might mean buying R comp rubber.

This is a great thread - my opinion shifted a bit back and forth over the course of reading it, a very good sign. But at the end of the day, someone who's put in the money and effort to prep their car to the rules' limit shouldn't ever lose to a calculator. That's just not right.

:shrug:

Jamin, you seem to be equating street tire use with being new to the sport and/or not very good. That is not the purpose of the T factor up here. It's simply to allow good drivers the option of using them and still having the opportunity to compete. Bad drivers on street tires will lose to good drivers on race tires after the factor, and vice versa.

[Jamin]

Bah - I re-read my post and you're right, it sounds that way - I rambled a lot. Here's the concise version:

T classes shouldn't affect attendance/recruitment. Newcomers aren't going to beat long time autocrossers (okay, there have been some amazing rookies at Nationals, but it's rare) whether they're on T or R's. So I fail to see why lack of a T moddifier should affect attendance. That's what Novice classifications are for.

Veterans or multi-year members requesting the T PAX seems to be the bigger issue. As an outside, 3rd party POV who doesn't know a single one of the people in this thread and has no bias in the discussion whatsoever, I put forth my humble opinion that the current rules say you can run DOT slicks in certain classes, and that we all know that thsoe tires are faster. Therefore, if you want to win in those classes, buy the tires. I know all the points raised about expense and carrying them to/from and so on - I face/faced every one of those hurdles, too. I found a way to get R rubber on my car when I couldnt afford it (heck, I couldn't afford to be racing at all back then, and barely can now), and placed better as a result.

All in all, after reading this thread and thinking it over HARD, I came to two DEFINATE conclusions.

1.) I think that a T moddifier is VERY unfair to the people who DO spend the money to set their cars up to the limit that's allowed, plain and simple. I can tell you right now that if I lived in your area I would campaign HARD to eliminate that adjustment, and

2.) If it stayed, I'd run streets no question. Because why on earth would anyone pay for R comps to gain an competitive edge when they can get the calculator to do it for them for free? Frankly, I can't believe anyone runs R comps at all with the system now in place - there's no reason to. :shrug:

[Dean]

Are you saying the person who spends the most money should always win, or have the rules in their favor, or that national interests should outweigh those of a local club?

This whole loosing to a calculator is silly to me. You get beat by drivers in cars, not inanimate objects like a calculator. The calculator is just the tool for applying the rules, just as a sway bar, bigger turbo, a tipped over cone, etc. You don't blame the cones you hit for your wins and loses, do you?

So far I have as yet to hear a T driver strongly complain about getting beat by a calculator and the new factor, and yet the data we have clearly shows we favor R compounds.

Would it make people happier if the rule was that T cars are the base and R compounds get a 1.025 multiplier? Is the group getting the modifier automatically assumed to be the group with the advantage?

A club is a collection of individuals.

The national rules specifically allow regions to make their own rules to meet the needs of the region.

I think we do a fairly good job balancing the needs of our membership.

We give the substantial membership who choose T tires for convenience and cost the ability to compete while attempting to give the advantage to those who choose R compounds.

I think over the period of a full season, it becomes clear to most competitors what cars and/or drivers are fast, regardless of tires or factors, Tire, or PAX related. If you honestly believe it is tires or a calculator that is the difference between you and another driver, offer to trade cars with that person during fun runs, or afternoon RNP and find out for sure. After a few runs maybe on a couple different courses, the truth should become evident.

[Jamin]

I won't clutter your thread further as an outsider, but I do want to say that no, I don't think that the most money should win or that national rules should outweigh local ones. I'll also say that I think the amount of effort that's gone into the ST moddifier (I read everything) shows commitment to making things as fair as possible, and it's laudable. IMHO, it's one more thing for people to disagree about, one more thing to raise contention when one driver beats another by .01 second with the new math. I'm showing interest here because it's something that several clubs elsewhere have tried, that a region I'm in may try someday. it';s worth watching. As a somewhat experienced autocrosser who takes the sport very seriously, I thought I'd throw anohter opinion on the pile; it is in no way intended as a critisism of the way you run your region.

However, I believe that if you're running in a class that allows R comps and you're not running them, the onus is on you to either realize that you're going to lose to an equal driver on slicks, or go into an ST class. :shrug:

I'm not against the idea that stock classes should be limited to 140+ tires. Heck, I dig the idea. I also think CAI and other common "bolt-on" mods should be allowed within reason - I don't get why catback exhaust is okay, but TB forward CAI isn't. Doesn't add up. A HUGE discussion is well overdue regarding shaking up MOST of the classes in SOLO II to fit the current car and aftermarket performance world; attendance would skyrocket if it was done right. But that, as I said, is an entirely different subject.

On topic and to be clear, I think that allowing for a street tire moddifier in a class that allows R comps isn't so much allowing people who don't want to run R comps to compete as it is a slap in the face to those who DO run the stickies. As to whether the math favors one or the other - that'll vary by class and course.

Buying a set of wheels is a one-time expense, one that most drivers who play this game are going to make anyway. Buying race rubber is a once or twice a season expense, and doesn't HAVE to be $1000 a shot for brand new A6's. I found 5 used S04's with 80%+ tread remaining for $400 shipped in a 245/40/17. They'll get me through most of the season. In the meantime, I can save up for another set of used tires or buy some new ones; certainly if I'd purchased this car earlier in the year I'd've been saving over the winter for "real" rubber as the car was purchased with DS in mind from the begining. Running R comps is a few hundred more per season than 615's or RE01R's. That's a LOT of money to me. But teh class I opted to go into means I need them if I want to PAX well or win my class, and it's a sport I take seriously, so I find a way to make it work.

Point is still valid: If there's a mathamatical scoring formula to compensate for the rubber, there's no point in buying the better stuff. It's a nifty idea, but it's unfair to people who prep to the limits of the rulebook.

And that's all just my opinion. ;)

[nmhansen]

Point is still valid: If there's a mathamatical scoring formula to compensate for the rubber, there's no point in buying the better stuff. It's a nifty idea, but it's unfair to people who prep to the limits of the rulebook.

And that's all just my opinion. ;)


And I can tell you that its a hell of a lot more fun on R compounds, and that's reason enough for me. :p

And, to bring up something that I think no one has said here yet (but has been said in person) is that the T modifier changed this year from .968 to .975. .968 was, in a lot of opinions, becoming an unfair advantage. Changing the modifier was the compromise because this is never going to be perfect, but if we are going to err, we should at least err on the side of the R compounds. Maybe it'll need to get revisited again next off-season, but that's what we've got to go with for this season.

We will see how it pans out this year, but I still really believe that (at least in our region) that the R compounds will take more trophies at the end of the year. If we want to look at the results from just the first event, 9 classes (between Open and Ladies) were contested with both R and T tires. 3 were won by T cars (AS, ES and BSPL). 6 (BSP, CSP, ESP, FSP, SM2, and BSL) were all won on R tire shod cars. The rest of the classes were all T or R based on dumb luck.

So yeah, its not perfect, but its what we decided to go with for this year.

[Jimmy Geck]

And I can tell you that its a hell of a lot more fun on R compounds, and that's reason enough for me. :p

And, to bring up something that I think no one has said here yet (but has been said in person) is that the T modifier changed this year from .968 to .975. .968 was, in a lot of opinions, becoming an unfair advantage. Changing the modifier was the compromise because this is never going to be perfect, but if we are going to err, we should at least err on the side of the R compounds. Maybe it'll need to get revisited again next off-season, but that's what we've got to go with for this season.

We will see how it pans out this year, but I still really believe that (at least in our region) that the R compounds will take more trophies at the end of the year. If we want to look at the results from just the first event, 9 classes (between Open and Ladies) were contested with both R and T tires. 3 were won by T cars (AS, ES and BSPL). 6 (BSP, CSP, ESP, FSP, SM2, and BSL) were all won on R tire shod cars. The rest of the classes were all T or R based on dumb luck.

So yeah, its not perfect, but its what we decided to go with for this year.

Its way more fun and worth the extra expense on R compounds. Thats why I'm not autocrossing on street tires its just not as fun.

[MPREZIV]

Its way more fun and worth the extra expense on R compounds. Thats why I'm not autocrossing on street tires its just not as fun.

And you're entitled to your opinion. As am I to mine. And mine is that R comps are too expensive for me, for this hobby.:p

["A" Stocker]

And you're entitled to your opinion. As am I to mine. And mine is that R comps are too expensive for me, for this hobby.:p

I have found that the "R" Comps on my Corvette are cheaper than if I were to run Street Tire's. I'm alittle biased since I have never raced on anything but "R" Comp or Goodyear Race Tires :):):):).

[Kevin M]

I have found that the "R" Comps on my Corvette are cheaper than if I were to run Street Tire's. I'm alittle biased since I have never raced on anything but "R" Comp or Goodyear Race Tires :):):):).

The cost of good street tires might be higher than for Hoosiers or V710s, but the cost per run is guaranteed to be lower since they last so much longer.

["A" Stocker]

The cost of good street tires might be higher than for Hoosiers or V710s, but the cost per run is guaranteed to be lower since they last so much longer.


Very True!!!!!!

[RBrown]

Very True!!!!!!

Back before we had R-compound tires the serious guys and gals would shave their tires. In fact, the first generation of R-compound tires circa 1990 were full tread and the serious folks would shave them too. I had talked to Jim Gandy a little about this at the first event while kicking around the idea of whether R-compound tires had gotten out of hand and should just be banned in stock class. The serious competitors will always spend the money to get an extra edge, even if that means shaving street tires to where whey only last a handful of events. That said, the difference between shaved street tires and full tread street tires would be less than between R-compound tires and street tires.

--- Rick

[sperry]

People still shave street tires today in the ST classes looking for an edge. Hell, folks shave their R-tires these days as well just to shave some extra camber into them in the stock classes!

Autocrossers are insane. They spend $100,000 for a $5 trophy and no award money. You could go wheel-to-wheel racing for that kinda money, and perhaps actually win some of it back if you're any good!

[Dean]

Autocrossers, PDX, TT, CT, etc amateur drivers are insane. They spend $100,000 for a $5 trophy and no award money. Fixed. :)

[Kevin M]

Fixed. :)

I would specifically exclude PDX/ "track day" drivers. They're not spending to sate competitive drive, they're just chasing more fun.

[sperry]

Fixed. :)
I won't disagree. But at least a trials car can pretty much go road racing without changes. A $100,000 SM autocross car still needs to have a rollcage, fire system, harnesses, window nets, fuel cell, etc added to it to hit the race track, and even then all the work on the suspension, brakes, etc probably would have to be changed to be competitive at the higher speeds.

[RBrown]

People still shave street tires today in the ST classes looking for an edge. Hell, folks shave their R-tires these days as well just to shave some extra camber into them in the stock classes!

Autocrossers are insane. They spend $100,000 for a $5 trophy and no award money. You could go wheel-to-wheel racing for that kinda money, and perhaps actually win some of it back if you're any good!


Yeah, there's no predicting what form obsessive compulsive behavior will take.
--- Rick

[AlexR]

I think we all agree that R comps are faster than tread wears of 140 or higher.

Attendance results in our region show over half of contestants do not equip their cars with R comps.



So we can stick by the national rules?
+ might attract new racers who want national practice, or people who skip due to not liking the street tire hadicap
- Might lose seasoned racers who can't afford R comps and can't stand being 2 seconds behind


We could level the playing field (which in affect makes is so people on R Comps wasted time and money )
+ might keep more seasoned racers who need to be competitive to enjoy their day
- Might lose national level drivers, and seasoned R comp racers who don't want to race where others who have not fully equiped their cars are on equal footing
- Might lose seasoned R comp racers and national level guys who feel we over shot the handicap

We could Take away some of the R Comp racers advantage that they bought but not all of it
+ might draw out more R comp fellows who will only race where the equipment advantage they bought comes into play
+ might draw seasons racers who don't buy R Comps but need to be compeitive to come out
- still might lose national level & Season R Comp drivers
- still might lose seasoned racers who don't buy R Comps as they know they are at a disadvantage.


did that make it clear as mud for anyone?

[RBrown]

I think we all agree that R comps are faster than tread wears of 140 or higher.

Attendance results in our region show over half of contestants do not equip their cars with R comps.



So we can stick by the national rules?
+ might attract new racers who want national practice, or people who skip due to not liking the street tire hadicap
- Might lose seasoned racers who can't afford R comps and can't stand being 2 seconds behind


We could level the playing field (which in affect makes is so people on R Comps wasted time and money )
+ might keep more seasoned racers who need to be competitive to enjoy their day
- Might lose national level drivers, and seasoned R comp racers who don't want to race where others who have not fully equiped their cars are on equal footing
- Might lose seasoned R comp racers and national level guys who feel we over shot the handicap

We could Take away some of the R Comp racers advantage that they bought but not all of it
+ might draw out more R comp fellows who will only race where the equipment advantage they bought comes into play
+ might draw seasons racers who don't buy R Comps but need to be compeitive to come out
- still might lose national level & Season R Comp drivers
- still might lose seasoned racers who don't buy R Comps as they know they are at a disadvantage.


did that make it clear as mud for anyone?



Another consideration is with regions and different autocross organizations doing different things if Reno did a street tire only rule for stock class let's say folks who run Sac, SFR, AAS, Cal Club, etc. would be less inclined to go to Reno events. I know you guys don't get allot of those so it may not be a major consideration for you but it is something to think about.
-- Rick

[Jamin]

*personal opinion, nothing to be offended at here* ;)

- Might lose seasoned racers who can't afford R comps and can't stand being 2 seconds behind

*snip*

+ might keep more seasoned racers who need to be competitive to enjoy their day



I guess that's the part I don't understand. I guess I just think that a seasoned racer who wants to remain comeptitive will find a way to run on R's if they're faster and the rules allow it in the class in question. :shrug:

[MattR]

For a good look at some Street Tire vs. Race Tire stats, check out today's BSP results. I drove very well in my (almost)fully prepped BSP Subaru vs. a Fully prepped BSP vette and finished 1.4 PAX seconds from the leader. On a good day, this is as close as I can get to Ray and Ken. Coincidently, on my best day running Hoosiers last year, I finished about 1.4 pax seconds behind as well.

[Cody]

Is it safe to assume that AWD cars tend to do better on street tires than RWD cars of the same class do? In other words, is it safe to say, a Vette needs race tires to be competitive where as an STi may be more competitive on street tires, in general?

[nmhansen]

Is it safe to assume that AWD cars tend to do better on street tires than RWD cars of the same class do? In other words, is it safe to say, a Vette needs race tires to be competitive where as an STi may be more competitive on street tires, in general?

I don't think its safe to say anything in this debate :p

[Kevin M]

Is it safe to assume that AWD cars tend to do better on street tires than RWD cars of the same class do? In other words, is it safe to say, a Vette needs race tires to be competitive where as an STi may be more competitive on street tires, in general?

Camber-challenged cars generally PAX better on street tires than race tires. Luke Kunze proved pretty emphatically that corvettes can do just fine on street tires.

[Cody]

That's right. I remember that. And IIRC, he ran RT-615's that were way too narrow for his rims due to that being the widest size of RT615 available for that rim.

Some day I'll run camber plates and race tires.

[Kevin M]

Yeah, I believe they were 265s.

[vic]

I ran both st and rt last season on the Mini and I believe the factor was really close. As far as wear goes it is 2 to 3 st to rt in a season with 2 drivers. We never wore out a set of st they just lost their grip. I was better on rt's and Renee was better on st's, but then I tend to overdrive the car.

[sperry]

Bump!

Food for thought: through 6 rounds of the championship, there have been only 4 street tire cars total to score a top 10 in open PAX. That's 4 out of 60.

Are all our region's top 10 PAX drivers on race tires? Or is the new ST factor too soft?

[dknv]

For round #6, the top 5 in open have all participated in national events, and have set up their cars accordingly (including use of race tires). They are not all necessarily local, regional-only drivers. This lineup looks appropriate to me, from a setup standpoint.

[197ASL]

So Kevin - What do you think about this whole debate now that you've driven on race tires? ;) Welcome to the dark side!!!!!!!!!!!!

[Kevin M]

I think by the end of the year when all the Street Tire proponents are running on race tires and crushing their previous competition, the debate about the multiplier will be settled. ;)

[MattR]

I'm pretty sure it will take a small miracle to stay in the top ten in PAX this season running street tires...

[Kevin M]

Here you go.

http://www.seccs.org/images/misc/traction_from_god.jpg

[solonut]

Here you go.

http://www.seccs.org/images/misc/traction_from_god.jpg
So your praying for a top 10 pax finish?????????????

[Kevin M]

So your praying for a top 10 pax finish?????????????

No that's the miracle Matt asked for. My top 10 is only a matter of time. :D

[MattR]

I'm talking about in the overall standings, not individual round. And yes, Scott's Good Year's would likely help.

[S2kreno]

Here you go.

http://www.seccs.org/images/misc/traction_from_god.jpg
Those look like street tires. Divine interventions AND a handicap too? Sign me up!

[Mark Sipe]

I'm pretty sure it will take a small miracle to stay in the top ten in PAX this season running street tires...


The $10,000 question is this a street tire factor issue or a driver/car issue?

Which nationally competitive drivers in appropriately prepared vehicles are on street tires and which are on race tires?

If the goal is to have people feel like they're hot stuff regardless of whether they really are or not then lowering the bar is always the easy answer

Or the region could just do away with the timers and give everyone a first place trophy to take home

IMO having a non-competitive competitive event is the ultimate irony ...

[sperry]

No Mark, this is the ultimate in irony:

http://www.seccs.org/images/misc/irony.jpg

[scarabracer]

Here you go.

http://www.seccs.org/images/misc/traction_from_god.jpg
I have been looking for somthing with more traction than my Eagles. Where can I get a set?????

[scarabracer]

Christa and I have decided to put street tires on the Z - I think this will help us in PAX - hahaha

[MattR]

If the goal is to have people feel like they're hot stuff regardless of whether they really are or not then lowering the bar is always the easy answer

Or the region could just do away with the timers and give everyone a first place trophy to take home

IMO having a non-competitive competitive event is the ultimate irony ...

My point is that it seems the small adjustment to the street tire factor has made scoring in PAX more difficult when compared directly to years prior. In the past, it was quite common to see street tire "t" class cars sneaking around the top ten, now, not so much. I think you people read WAY too far into things , I didn't say anything about lowering the bar or first place trophies for everyone, lighten up.

[Mark Sipe]

My point is that it seems the small adjustment to the street tire factor has made scoring in PAX more difficult when compared directly to years prior. In the past, it was quite common to see street tire "t" class cars sneaking around the top ten, now, not so much. I think you people read WAY too far into things , I didn't say anything about lowering the bar or first place trophies for everyone, lighten up.

Matt,

If you believe that to be true then obviously the central point wasn't conveyed properly by me, but to reiterate; just because the situation you describe is the case doesn't mean there's anything wrong with the scoring factor. Assuming that you understand in whole that the entire factoring system is based on the best driver, in the best car for a given class class prepared to it's fullest extent, and both operating at their maximum potential. It certainly does not mean that there will any equity in the final distribution for a region this small and with such little national level experience. It was never intended to equalize lesser drivers in lesser vehicles.

Otherwise I apologize if you somehow took my response as a personal affront. I did not call you out by name, but rather chose your post from the many to be the springboard for making my own point; nothing more, nothing less.

Mark

[jim.gandy]

Weeks and weeks have gone by without a post to this controversial thread. Does that mean everyone is finally convinced that our 2008 Street Tire Factor, 0.975 (1.5 seconds on a 60-second course) is the most accurate number possible? Oh yeah, sure...

It's time to start the discussion/whining/name-calling that will guide the Board of Directors in their search for our 2009 factor (assuming we don't ****can the whole concept).

I'll throw out the first pitch/*****: As a Street Tire driver, I think the change from 0.968 to 0.975 went a bit too far, and I think the event results this year support that idea. Example: We've had 13 events so far. Looking at the Top Ten in PAX for each of those thirteen events, I count only six instances where a Street Tire car has finished in the Top Ten -- that's six out of 130.

I admit I haven't looked as closely at the individual class results as I should have. Do we have any classes this year where there's an ST vs R matchup?

[Kevin M]

I admit I haven't looked as closely at the individual class results as I should have. Do we have any classes this year where there's an ST vs R matchup?

Patty vs. Debbie in B Stock (sort of). Nick vs. Cody in ESP. Vic, Rene and Alex in AS vs. Randy, Peggy and Kelly.

For the most part, there is a significant advantage to the race tires this season, whereas last season the consensus among ST drivers was that the race tire advantage (when it's not cold anyway) was small enough that it could be overcome with a good run.

[nmhansen]

I know at least ESP has a good ST vs. R matchup. We're keeping pretty even, and if you take out the uncontested wins I think we are within 2 points of each other.

So, now its down to the individual performance of both of us. Which is tricky to even get into (and if you get down to it, its not very accurate to extrapolate it out to the grander R vs. ST debate). I finished higher in both class and PAX last year, but Cody is driving very well this year. Much better than last year, and I've spent the year learning to drive again. So, does that make us even? Or is one of us chasing the other? Its really hard for me to say. I feel like I'm chasing him as much as he's chasing me.

I think the factor is fine where its at. From anecdotal evidence, I would think that certain tires (both race and street) can give an advantage over the factor, and certain tires cannot. But I hardly think we want to go down the road of rating and re-rating individual types of tires. I think both Hoosiers and the Bridgestone RE-01R tires maybe have a slight advantage over the factor, but the rest don't.

[dknv]

Patty vs. Debbie in B Stock (sort of). Nick vs. Cody in ESP. Vic, Rene and Alex in AS vs. Randy, Peggy and Kelly.I'd be alot more willing to look at match-ups where the cars and setup are the same or very similar, and where we have similarly experienced drivers. Otherwise, as we have rehashed over and over again, too many variables exist to (imo) glean meaningful data.

I'll give you one example regarding 'Patty vs. Debbie', using one design element, of many that can affect results: on Saturday's course, we had 2 short slaloms, something the RX-8 can oftentimes traverse faster than the 350z; seems to have shown in the results. (I really wish we both had data acquisition in our cars, so that my 'gut' feeling could be proved out.)

[Cody]

I know at least ESP has a good ST vs. R matchup. We're keeping pretty even, and if you take out the uncontested wins I think we are within 2 points of each other.

So, now its down to the individual performance of both of us. Which is tricky to even get into (and if you get down to it, its not very accurate to extrapolate it out to the grander R vs. ST debate). I finished higher in both class and PAX last year, but Cody is driving very well this year. Much better than last year, and I've spent the year learning to drive again. So, does that make us even? Or is one of us chasing the other? Its really hard for me to say. I feel like I'm chasing him as much as he's chasing me.

I think the factor is fine where its at. From anecdotal evidence, I would think that certain tires (both race and street) can give an advantage over the factor, and certain tires cannot. But I hardly think we want to go down the road of rating and re-rating individual types of tires. I think both Hoosiers and the Bridgestone RE-01R tires maybe have a slight advantage over the factor, but the rest don't.

Hey Nick, thanks for the compliment. :) Honestly, I doubt I'm driving all that much better than last year. Driving with Dean instructing at RFR recently showed me a bunch of bad habbits I have developed...and my mods have been the same as last year (prior to the flywheel Cory just installed in my [our] car[s] :)). I'd say that the RE01R's are making me more competitive than the old 2nd season RT615's did, though; and as you pointed out, this is your first year on race tires. Additionally the shorter courses and "cheater" morning ride alongs have helped combat my bad memory A LOT!

Do you think you'll run your RE01R's this year at all? A RNP on them some afternoon, compared to your morning times, would provide good anecdotal data for this debate, I'd think.

[Kevin M]

I think Jim and Don should go in halves on a set of Hoosiers and swap wheels every saturday night. That should do nicely!

[MattR]

I think Jim and Don should go in halves on a set of Hoosiers and swap wheels every saturday night. That should do nicely!


Or Matt and Dean :devil:

[k-dogg39]

Or Matt and Dean :devil:
+1 DO IT!!

[nmhansen]

Do you think you'll run your RE01R's this year at all? A RNP on them some afternoon, compared to your morning times, would provide good anecdotal data for this debate, I'd think.

I thought about it, but I don't know how good that'll be. I'll probably just push around like crazy looking for all my grip.

[Mark Sipe]

if you honestly think that swapping between street tires and race tires without any other changes will prove anything then you don't really grasp the subject, they require completely different setups for optimization

if you want to compare Patti vs Debbie then you also have to factor in that the 350Z is not the car to have in BS, the real crux of the issue is that if the times aren't what you want them to be regardless of all the other factors then something must be wrong. Well what's wrong is that the street tire drivers aren't going to be happy unless their times are adjusted to be competitive regardless of whether it's invalid. Again, the factor has to be based on the best drivers, with the best optimized setups, in the best cars for the class. Then there are other factors such as course design ve altitude, etc. etc. If you're short in one or more of these factors then you can't expect to running with the top performers regardless of how disheartening it may be.

As an example, I run fairly high here, but have been getting my butt handed to me at national and divisional events. Ray and Ken pretty much dominate with their BSP Corvette, but if Tom Berry came here with his BSP Evo they'd get blown right out of the water, he completely dominates the BSP class right now. If you don't get out and experience life in the other ponds then you'll never truly understand how big the fast fish really are ....

[MikeK]

Ray and Ken pretty much dominate with their BSP Corvette, but if Tom Berry came here with his BSP Evo they'd get blown right out of the water, he completely dominates the BSP class right now. If you don't get out and experience life in the other ponds then you'll never truly understand how big the fast fish really are ....

We got a sampling of that at hawthorne, there was a BSP evo who beat Ray and Ken to take the pax win on day 1.

[Cody]

if you honestly think that swapping between street tires and race tires without any other changes will prove anything then you don't really grasp the subject, they require completely different setups for optimization

if you want to compare Patti vs Debbie then you also have to factor in that the 350Z is not the car to have in BS, the real crux of the issue is that if the times aren't what you want them to be regardless of all the other factors then something must be wrong. Well what's wrong is that the street tire drivers aren't going to be happy unless their times are adjusted to be competitive regardless of whether it's invalid. Again, the factor has to be based on the best drivers, with the best optimized setups, in the best cars for the class. Then there are other factors such as course design ve altitude, etc. etc. If you're short in one or more of these factors then you can't expect to running with the top performers regardless of how disheartening it may be.

As an example, I run fairly high here, but have been getting my butt handed to me at national and divisional events. Ray and Ken pretty much dominate with their BSP Corvette, but if Tom Berry came here with his BSP Evo they'd get blown right out of the water, he completely dominates the BSP class right now. If you don't get out and experience life in the other ponds then you'll never truly understand how big the fast fish really are ....

I'm confuzzled. How can we use data from the best drivers with the best cars to determine what the street tire modifier should be? I was under the impression that there is no street tire modifier at the national level so everyone just runs race tires right? Obviously ST is the exception, but again, they all just run street tires right? Exactcly what data are you suggesting that we look at?

[jim.gandy]

if you honestly think that swapping between street tires and race tires without any other changes will prove anything then you don't really grasp the subject, they require completely different setups for optimization

We're not looking to "prove" anything, we're just trying to pursue any avenue that could shed some light on the subject. A swap-test would not be accurate, you are correct. But, for example, if several swap-tests tended to show that 0.975 is still too much handicap, we might nudge the factor higher for the next year. A swap-test would, IMO, be more revealing than watching the results for dissimilar cars and different drivers, which is what we're reduced to doing now.

There's no way we can achieve an absolutely accurate factor. And that's not the goal, because there are plenty of other sources of inaccuracy built into the system we have to work with -- the SCCA classes are screwy, PAX is screwy, and altitude makes both of those things worse. Just like with the classes and PAX, if we're going to have a Street Tire Factor we need to accept that it won't be precisely accurate.

Which brings up the question, why should we have a Street Tire Factor? It's worthwhile to review the situation. The ST Factor exists to try to salvage competition at the local level. A significant number of entrants resist going to R compounds. There are enough of them that their voices need to be heard. Clearly, if we don't provide a way for them to compete, not just drive, many of them will leave the club prematurely. We tried offering a single Street Tire class with the results indexed by PAX -- it was so successful it quickly grew too large to fit in a run group, and the remaining R-compound entrants were mostly reduced to one per class or so. The current system, integrating ST and R cars using a guesstimate factor, is our second attempt at a solution. We're certainly open to considering other approaches.

My point is that the ST vs R problem isn't going away, not until the National SCCA outlaws R tires in Stock. Down here at the local level, we're forced to make the best of a bad situation for the good of the sport as a whole. So, let's keep those ideas coming!

[Joeyy]

I thought about it, but I don't know how good that'll be. I'll probably just push around like crazy looking for all my grip.

You two having so much fun makes me miss my wagon.:|

[Cody]

What, you enjoyed winning or something? :P

[jim.gandy]

Folks, it's okay if you want to cover the same territory multiple times, debating whether real-world tests are valid, who could perform the tests, what are the effects of suspension changes, all that. Could we do testing? Yes. Would everyone accept the results? Not a chance.

It seems painfully clear that we're not going to agree, and so we have to muddle on somehow. Unless somebody comes up with a brilliant idea, we need to recognize that Reno Region's Street Tire Factor is a political issue, not a technical one.

That's why I asked for input, and I'm asking again -- what change, if any, should the Board of Directors make in the Street Tire Factor for 2009?

[Cody]

I'm cool with 1.5 seconds. I think it puts the street tire drivers at a slight disadvantage...which it should...otherwise people would go to street tires for strategy, not just for cost/convenience. As I understand it, race tires, add a lot to the fun factor and they're what everyone outside of the Reno region uses to be competitive so they should continue to have the advantage.

[Kevin M]

Cody's pretty much got it from the street tire driver perspective. A properly prepared, well-driven race tire car should beat a similarly prepared, similarly well driven comparable car on street tires. As long as the modifier is close enought hat a good day behind the wheel can put the street tire driver in front, I think that's as close as we're going to get to universal acceptance of the street tire factor.

["A" Stocker]

We've went over this for years in Sac. the only way to truly do a street tire factor is to have a factor for every class and it has to change with better tires, better drivers, better etc, by using only one factor and making it relatively close, I think that's the best we can do. Rick Brown developed the first Street Tire Pax for the COCS Muscle Car Challenge and that factor worked great until tires got way better. Both groups (Reno / Sac.) will never have a perfect factor, but as long as people are having fun and nobody gets too frustrated--we work with what we have--now let's go race...