darksky1984

More tire is always better as long as your rim is wide enough that as you said its not rolling the beads over.

Andy13186

What about on the front? I kind of had the idea that wider wasnt always better on the front. I think most lambos/ferraris etc go with 255's on the front. i thought wider on the front would somehow reduce steering response and turn in quickness or something.. Im no expert though

Mishri

I might take it out once this year just to do it. I think auto-x and road courses put the most strain on a vehicle, wearing out suspension, tires, transmission/clutch, and brakes... drag racing just wears out tires and clutch.. and all are a strain on the engine, but they aren't going bad from it

For a straight line you want smaller tires up front for less weight, for auto-x some people even in rwd cars put slicks on all 4 wheels for traction in the turns, so i think you want biggish tires up front too. but i could be wrong, the guy i talked to could have been BSing me about the slicks up front on his mustang, but he was a regional champ in his class.

nwb818

auto cross shouldn't damage the transmission, at least for our cars. i kept it in second the entire time.

darksky1984

Most guys tend to have the same size tires on all four corners for balance purposes. I do it for that reason and it makes rotating tires for longevity better. Wide front tires help get that grip in the turn which is what you need the most in an auto-x. And I bet the guy did have slicks up front if he was as good as he claimed. I went as wide as I could go for the class that I'm racing in, which was 265 on a 9" wheel. The class above mine I could run 10" wheels with 285 tires.

Whiskey11

I actually gained 10mm of width switching from 235's to 245s. The general rule of thumb is to keep the tire no more than an 1" wider or smaller than the rim to maintain "optimal" steering response and grip. I guess the Hoosier A6 doesn't mind being crammed on a smaller rim?

As with Darksky, I'm limited to 265 on a 9" wide rim due to class rules. As to WHY I went with 245s and not something wider? I opted for 245 because I didn't feel a 265 on an 8.5" rim would be safe for daily driving use.

To counteract the tire stresses you inflate the tires up. On the stock KDWS I ran 38 psi front and 35 PSI rear. I'm not sure on what the Star Specs will be as the first event is this weekend. It would take quite a bit of lateral G to pop the bead. I've not seen it happen in my limited experience (1 year of autocross :P).

S197 650

This is the exact setup I want on my car. I was somewhat worried about Ultralite's low drop / soft spring rates. How are they in Auto-X?

darksky1984

I've had no major issues with the drop. The springs handle great in the turns. I'm glad I got the ultralites and a bit more drop. My daily ride isnt harsh at all. I just run the shocks on full soft for daily driving.