Wheel/tire size for Auto-x

[thekid]

Do any of you have any experiance with auto-x (autocross)? if so any ideas on what wheel/tire size will fit and still be the best compromise between size and grip? IE. I don't want 18's or 19's. I'm thinking 16's would be the largest but 15's or even 14's would work depending on how wide that can be fitted with out rolling the fenders.

[El Presidente]

225 is as wide as you can usually go without rolling. IMO 17s are the best wheel/tire size. You get the same grip as most 18s and 19s, but without the added weight. The downside is more sidewall flex. 17x7.5-17x8 should be the size to look for. 7.5 is the narrowest you should go for auto-x. 16 is the smallest diameter I would go, but some will tell you 14 or 15 is best w/ the loest profile available (generally due to weight and a lowering effect).

[thekid]

Originally posted by El Presidente@Feb 24 2004, 12:56 AM
225 is as wide as you can usually go without rolling. IMO 17s are the best wheel/tire size. You get the same grip as most 18s and 19s, but without the added weight. The downside is more sidewall flex. 17x7.5-17x8 should be the size to look for. 7.5 is the narrowest you should go for auto-x. 16 is the smallest diameter I would go, but some will tell you 14 or 15 is best w/ the loest profile available (generally due to weight and a lowering effect).

Most of the fastest cars I have seen have small but insanely wide tires on their cars. Some of the fenders might be rolled but most are not. You get advantages such as a little more acceleration ect. ect. from smaller tires, but it's only worth it if you can get wide enough tires. Also where would be the best place to find CHEAP wheels? I'm have a street set and I need a track set just to make things easier on myself.

[thekid]

I got this advice from a e36 driver with track time. He said he ran 225/50/15 all around on 15X7 and it was a good setup. Does this sound reasonable? with the Toyo RA-1 street/track tires?

[El Presidente]

The width is good, the only problem you will encounter with that size is sidewall flex. If these are going to be track only wheels/tires, I would go for a the lowest profile tire to fit the 15, but the speedo and odo would be off.