Autox Street Tire Advice

Chuck Branscomb · **Posted:** Thu Sep 12, 2013 12:45 pm

Thanks Dick -- so street class will be identical to current stock class other than the tires and wheel diameter allowance?

DickRasmussen · **Posted:** Thu Sep 12, 2013 1:10 pm

Chuck Branscomb wrote:

Thanks Dick -- so street class will be identical to current stock class other than the tires and wheel diameter allowance?

I think so other than some Appendix A classing changes for the street tire cars including (I think) merging of HS with GS. R tire classes may be status quo for 2014 but I really haven't paid attention. I don't think the wheel diameter option applies to the R tire class.

Next year stock Street and stock R will be official. In 2015 the only R tire stock class will be Super R (SR) assuming high enough attendance at Nats. Letter designations are, for example, FS and FR. Rick Ruth will probably tweak his new PAX numbers for 2014 for the street tire classes since there is some data to indicate that the initial .975 number isn't accurate depending on the class. Either too high in some cases or too low in others.

RodneyWright · **Posted:** Thu Sep 12, 2013 2:29 pm

DickRasmussen wrote:

Chuck Branscomb wrote:

Thanks Dick -- so street class will be identical to current stock class other than the tires and wheel diameter allowance?

I think so other than some Appendix A classing changes for the street tire cars including (I think) merging of HS with GS. R tire classes may be status quo for 2014 but I really haven't paid attention. I don't think the wheel diameter option applies to the R tire class.

Next year stock Street and stock R will be official. In 2015 the only R tire stock class will be Super R (SR) assuming high enough attendance at Nats. Letter designations are, for example, FS and FR. Rick Ruth will probably tweak his new PAX numbers for 2014 for the street tire classes since there is some data to indicate that the initial .975 number isn't accurate depending on the class. Either too high in some cases or too low in others.

I think someone wise in the club made that prediction earlier this year. Wasn't equitable across classes...

DickRasmussen · **Posted:** Thu Sep 12, 2013 2:38 pm

RodneyWright wrote:

I think someone wise in the club made that prediction earlier this year. Wasn't equitable across classes...

With the SCCA road tire classes it was potentially mitigated by separate classes for Front, All Wheel, and Rear but really didn't address the high/low power cars in the same class. Rick will have fun . . .

Ryan Holton · **Posted:** Thu Sep 12, 2013 3:36 pm

RodneyWright wrote:

Finding any aftermarket 6.5" wide wheel is impossible.

Hogwash

6
http://www.discounttiredirect.com/direc ... xposed=wth

A handfull but Tire Rack doesn't let you sort by width
http://www.tirerack.com/wheels/results. ... sort=Brand

BriceJohnson · **Joined:** Thu Apr 13, 2006 7:33 am **Posts:** 2230

How's about 16x6.5" somewhere between +47 to +58, 5x114.3. It gets a bit more difficult when you narrow that down.

Edit: looks like one of those DOES qualify, the MB twist wasn't around last I checked.

RodneyWright · **Posted:** Thu Sep 12, 2013 4:04 pm

Ryan Holton wrote:

RodneyWright wrote:

Finding any aftermarket 6.5" wide lightweight 17" wheel is impossible.

Hogwash

6
http://www.discounttiredirect.com/direc ... xposed=wth

A handfull but Tire Rack doesn't let you sort by width
http://www.tirerack.com/wheels/results. ... sort=Brand

OK... I've corrected my statement. There are some 16" wheels to be had. Discount tire doesn't offer weights and the few I found on tire rack were too heavy. The ones I bought from Brice, while exceedingly ugly, only weigh ~16lb. I can live w/ that.

JamesShort · **Posted:** Thu Sep 12, 2013 4:07 pm

RodneyWright wrote:

I think someone wise in the club made that prediction earlier this year. Wasn't equitable across classes...

That wise person should be president....

Quote:

With the SCCA road tire classes it was potentially mitigated by separate classes for Front, All Wheel, and Rear but really didn't address the high/low power cars in the same class. Rick will have fun . . .

Honestly I think those 3 classes are worthless because clearly an across the board 2.5% PAX discount doesn't work for the spectrum of cars regardless of drive type. Hell, even within the SAME class, it isn't fair but with a full classing restructure next year, it might get taken care off.

Example, even amongst outgoing SS cars, the Elise and Corvette are two top contenders (both RTR, but who cares about the A/F/R.....said James Milko...). The Corvette is going to be terrible next year on street tires since in the ESPT categories, you don't really find much 300+mm tires and even then, the Corvette has so much torque it'll be hard to get it down on street tires whereas the Elise might find it quite comfortable to perform on street tires and hence in a Super Street class, the Vette might wither away (yes I know there is a Super R class that they are talking about, but that's not relevant to the convo). So even within the old Stock-R classes, there is inequity to compare all of the same cars to each other going from race rubber to street tires. Then enter the fixed 2.5% PAX discount across all stock classes, which makes even less sense. For Street category next year and onward, I'd hope that each class gets A) an appropriate PAX reduction based on the type of cars in the class (ie FS and SS gets a big discount for running street tires and HS/GS or CS or ES get relatively little discount and B) the Street classes cars likely can't be a 1-1 with the 2013 Stock classes since going from r comps to street tires is going to limit both the size of tire and availability of said size as well as the feasibility of putting decent power down on the smaller tires.

:soap:

JamesMilko · **Posted:** Thu Sep 12, 2013 4:22 pm

JamesShort wrote:

but who cares about the A/F/R.....said James Milko...

Looks like we've got a wise guy here.

Ryan Holton · **Posted:** Thu Sep 12, 2013 4:51 pm

RodneyWright wrote:

Ryan Holton wrote:

RodneyWright wrote:

Finding any aftermarket 6.5" wide lightweight 17" wheel is impossible.

Hogwash

6
http://www.discounttiredirect.com/direc ... xposed=wth

A handfull but Tire Rack doesn't let you sort by width
http://www.tirerack.com/wheels/results. ... sort=Brand

OK... I've corrected my statement. There are some 16" wheels to be had. Discount tire doesn't offer weights and the few I found on tire rack were too heavy. The ones I bought from Brice, while exceedingly ugly, only weigh ~16lb. I can live w/ that.

Ok, there are no 17x6.5" wheels :lol:

Why not 15x6.5" wheels?

21 to choose from, cheaper too!

http://www.discounttiredirect.com/direc ... xposed=wth

http://www.tirerack.com/wheels/results. ... cial=false

I love spending other peoples $$ :lol:

BriceJohnson · **Joined:** Thu Apr 13, 2006 7:33 am **Posts:** 2230

Hatchbacks came with 17's, so 15's are a no go for him.

I could run 15x6.5 on my sedan though.

DickRasmussen · **Posted:** Thu Sep 12, 2013 5:28 pm

JamesShort wrote:

Honestly I think those 3 classes are worthless because clearly an ac

Quote:

ross the board 2.5% PAX discount doesn't work for the spectrum of cars regardless of drive type. Hell, even within the SAME class, it isn't fair but with a full classing restructure next year, it might get taken care off.

True and well known. The Road Tire classes are gone after this year due to "Street" starting next year. What Rick Ruth does with PAX and what SCCA Pro Solo does with its indices will be interesting. In any case my chance to take advantage of a softer than previous CM PAX is going away thanks to those "curve breaker" hotshots from other parts of the country.

FYI at an EVO TnT just before Nationals James Newman's AS Corvette was used to compare A6's with Rivals. Drivers were Sam Stano, Mike Johnson, and James Newman. The Corvette on Rivals was more than .975 slower than on Hoosiers.

Chuck Branscomb · **Posted:** Thu Sep 12, 2013 7:03 pm

DickRasmussen wrote:

FYI at an EVO TnT just before Nationals James Newman's AS Corvette was used to compare A6's with Rivals. Drivers were Sam Stano, Mike Johnson, and James Newman. The Corvette on Rivals was more than .975 slower than on Hoosiers.

Dick I assume you're referring to the multiplier as opposed to 0.975 seconds. Any details on the results? Link?

Matt McGrain · **Posted:** Thu Sep 12, 2013 7:38 pm

DickRasmussen wrote:

FYI at an EVO TnT just before Nationals James Newman's AS Corvette was used to compare A6's with Rivals. Drivers were Sam Stano, Mike Johnson, and James Newman. The Corvette on Rivals was more than .975 slower than on Hoosiers.

Wow, that's incredible that the gap between the best street tire and the best r-comp is less than a second now, especially on a power car. It would be cool to see a comparison between a Rival and an original Azenis (assuming you could get a fresh one) to see how much the ST's have improved.

I'm leaning toward a set of Dunlops for next year just because the 205 section width Rivals are so wide, any advantage over the 195 ZII will probably be lost because of the narrow 6" wheel.

DickRasmussen · **Posted:** Thu Sep 12, 2013 10:38 pm

Just to clarify the .975 is a multiplier that has been used by Rick Ruth and others. It was NOT the time gap. For your info the best FS time at Lincoln on Hoosiers was a 2012 Mustang GT with a 133.674 for both days combined. The best Road Tire Mustang time was a 2012 GT on large Dunlops with a 141.231 (before applying PAX since RTR is a mixture of classes). The multiplier to "equate" those times is about .947.

I lifted this from Danny Kao's post on James Newman's Facebook page. Test was on August 25 at a site in Doswell, VA.

Here is the result of Today's Rival/A6 comparison test. No editorial from me since I only took three runs to scrub the Rivals in, and I didn't drive the A6s. So this is data only. I am sure Sam, Junior, Courtney and Newman can chime in on their driving impressions:

Car: Newman's FRC, Koni Yellows, 33mm front bar, X-pipe
Tire tested for the data below: New non-shaved Rival
Location: Doswell, VA
Date/Time: 8/25/2013, 11am.
Weather: 72 degrees. Sunny.
Course: 1 high speed sweeper, 2 tight sweepers, slaloms, transitions, 3 straights.

Drivers and their times:
Sam 1 - 46.346
Sam 2 - 46.357. +1
Sam 3 - 46.510 +1

Courtney 1 - 47.860
Courtney 2 - 46.684
Courtney 3 - 46.874 +1

Newman 1 - 47.684
Newman 2 - 47.959 + 1
Newman 3 - X

Junior 1 - 48.248. +2
Junior 2 - 46.753
Junior 3 - 47.136

Kao scrub in time in FRC - 47.212
Kao fastest STX time - 45.654

STU
Wampler 1 - 46.332
Wampler 2 - 45.951
Wampler 3 - 46.399
Wampler's fastest STU time - 45.7xx, front right shock was blown during the runs.

A6, 1:20pm, 77 degrees and Sunny
Tire tested for the data below: One event A6
Date/Time: 8/25/2013, 1:20pm
Weather: 77 degrees. Sunny.

Drivers:

Sam 1 - 44.188
Sam 2 - 44.253
Sam 3 - 44.226

Newman 1 - 44.701
Newman 2 - 45.007
Newman 3 - X

Junior 1 - 44.371
Junior 2 - 44.427
Junior 3 - 43.860 +1

Courtney did not run A6's.

Street tire multiplier:

Sam - 0.953
Newman - 0.937
Junior - 0.938

Similar test conducted last year on a Solstice Z0K yield a street tire multiplier of 0.975.

That's it!!! Enjoy....

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