Tire/Wheel setup for Autox? Any issue running rt660s up front and A052s in back?

[nonopenotme]

Hey all - trying to figure out a set of wheels and tires to run for the upcoming autox season. I previously ran RT660s on my Focus RS and enjoyed them, but I have always heard good things about the A052s..

I am looking to get a set of Apex VS-5RS 18inch wheels but I cant decide whether to go staggered or not. If I go staggered, the only real competitive option is to get the yokos in a 265/35-18 & 275 or 295/35-18 rear but I've been reading the A052s have a softer side wall and need a lot of camber (i'll be completely stock). Not wanting to roll over my sidewalls, I was thinking running RT660s up front and the A052s in the rear. Is there any issue with this? If i run staggered, an 11 inch wheel is slightly too wide for a 275 tire and the RT660s dont come in anything wider for the supra (according to Apex's fitment guide)

I was trying to see what David Marcus was running in nationals this past year (he placed second in B street with his supra) but all I can see was that he ran a multi tire setup. Anyone know what sizes and which tires he went with?

What tires and wheels are you guys running for autox?

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[AHP]

HPDE instead of autoX, but if I were to do it over again I would have gone with a square 18" (10-10.5" wide) setup.

 

[94boosted]

If you want to stay Street Class Legal, then you need to run a 9" Front and a 10" Rear wheel. 18" or 19" is fine. I believe a popular option is the 265/35/19 F and 295/35/19 R Falken RT 660, could also do a 255/285 Bridgestone RE71RS. Not sure what there is for 18" sizes that won't reduce the height of the tire by a decent amount.

 

[nonopenotme]

HPDE instead of autoX, but if I were to do it over again I would have gone with a square 18" (10-10.5" wide) setup.

How come?

 

[Evolution]

I dont know what your class restrictions are but if you can do a square 11" setup on rt660s in 315s, that is ideal. Car handles so much better than my old staggered 10/11" setup. This is on an 18" wheel too. The only issue with the rt660s in a 315 is that they are a bit shorter than the factory tire, which really isnt a problem.

 

[AHP]

How come?

To combat the inherent understeer; especially high-speed understeer. Low speed turn-in is pretty good so maybe not as big of an issue for autoX. HPDE and especially high speed tracks the lack of front grip is unnerving. I'm running 255/285 RE71RS.

I'm not familiar with autoX class restrictions but if allowed I would highly recommend SPL front lower control arms (at least) so you can dial up the negative camber up front.

 

[nonopenotme]

I dont know what your class restrictions are but if you can do a square 11" setup on rt660s in 315s, that is ideal. Car handles so much better than my old staggered 10/11" setup. This is on an 18" wheel too. The only issue with the rt660s in a 315 is that they are a bit shorter than the factory tire, which really isnt a problem.

That doesnt fit on stock suspension right?

 

[Evolution]

That doesnt fit on stock suspension right?

Rear fits fine, front can only take a 10" wheel stock. Get to modifying haha.

 

[nonopenotme]

To combat the inherent understeer; especially high-speed understeer. Low speed turn-in is pretty good so maybe not as big of an issue for autoX. HPDE and especially high speed tracks the lack of front grip is unnerving. I'm running 255/285 RE71RS.

I'm not familiar with autoX class restrictions but if allowed I would highly recommend SPL front lower control arms (at least) so you can dial up the negative camber up front.

Are you running a 9 inch wheel up front? Is that why you stuck with 255

 

[FLtrackdays]

To combat the inherent understeer; especially high-speed understeer. Low speed turn-in is pretty good so maybe not as big of an issue for autoX. HPDE and especially high speed tracks the lack of front grip is unnerving. I'm running 255/285 RE71RS.

I'm not familiar with autoX class restrictions but if allowed I would highly recommend SPL front lower control arms (at least) so you can dial up the negative camber up front.

How much toe out are you running up front? Just curious as I’m running 275/35-18 square for the ease and massive availability of tires. Looking at getting more of that inherent understeer out as well. I’ve been spoiled like you with lots of seat time in a S2K.

 

[AHP]

Are you running a 9 inch wheel up front? Is that why you stuck with 255

Yes, I started tracking the car on stock wheels/tires. I then went to the RE71RS to see how things went from there -- massive improvement but still flawed. By the time I determined I wanted a square setup I bought track wheels for both of my Corvettes for 2023 instead..

How much toe out are you running up front? Just curious as I’m running 275/35-18 square for the ease and massive availability of tires. Looking at getting more of that inherent understeer out as well. I’ve been spoiled like you with lots of seat time in a S2K.

0 toe up front. The initial turn-in is so immediate/abrupt I think toe out would make it even more twitchy and I don't think it would help the front end plowing at high speed, but I could be wrong. If I were running autoX or smaller, tighter tracks it might would be worth the experiment

 

[MKVDevo]

just dropping in to say I really wish RPF1's were available wider in 18's.

 

[Ryan T]

David was codriving in my car. We were on 275 rs and 295 yoks.

 

[nonopenotme]

David was codriving in my car. We were on 275 rs and 295 yoks.

Very good to know, thank you. What are the benefits of going staggered instead of square? Are you going to continue running that set up this year?

 

[Ryan T]

Very good to know, thank you. What are the benefits of going staggered instead of square? Are you going to continue running that set up this year?

It's surface dependant. I won the Peru tour on 275 Square 660's. DiSimo won the Axis Allied tour in my car on 275 Square rs's. You get better rotation running Square, but more wheel spin off the corner.

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