Rain tires for Autocross

[dgoetz]

I have decided to order rain tires with wheels for autocross. Everyone likes the Hoosiers, but they arn't sure about sizing. I would think you would run narrower tires for the wet like you would do for snow.
I have an 04 ZO6 and thought about 245/40X17 for the frt on stk rims and 275/40X18 for the rear. The 245's are a little small for a 9&1/2" rim but would this be the best choice. If it is legal to run narrower rims than stk in SS class would I be better off to put those tires on stk C5 rims?
What is everybody else running on their C5 ZO6's for rain tires and why?

[DJWorm]

BY FAR....the best DOT rain tire for AutoX and the track is Hoosier DOT Radial Rain Tire. These are based on Hoosier Dirt Stockers and have great grip.

For C5 Z06 Super Stock use:
FRONT - 275/40x17 on 9.5x17
REAR - 305/30x18 on 10.5x18

For C5 Z06 ASP or SM2:
FRONT - 305/30x18 on 10.5x18
REAR - 315/35x17 on 11x17

For C6 Z06 all classes
305/30x18 on 10.5x18 on all 4 corners

Starting Cold Pressure is 5 psi HIGHER than A6 dry starting cold pressure.

Hoosier's are great on a wet course with standing water. In dry conditions these will deteriorate quickly and blister.

Run all shocks at normal ReBound setting but reduce all Bump settings to softest setting on all 4 corners.

Run in Competition Mode or with both TC and AH ON.

An alternative DOT tire is Goodyear DOT ZRS "S" Compound. These only come in 17" and therefore can only be used on a C5 Z06 in ASP or SM2.
FRONT - 275/40x17 on 9.5x17
REAR - 315/35x17 on 11x17

These are not quite as good as the Hoosier DOT Rains. However they will last longer and can be used in drying conditions (but of course are poor in complete dry as compared to A6's). They will blister if used in dry competition. They can even be driven on the street and in fact are a good wet Spring and late Fall street tire. They will wear very fast on the street.

BTW the OEM Goodyear F1 Supercar tires make a good intermediate tire on a mixed dry/damp surface with NO standing water.

Run all set ups on race wheels with the SCCA allowed +0.25" offset built in to give a 0.5" wider track.

[wvphoto]

THE man has spoken..

thanks DJ

[froggy47]

Hold on guys, just out at the SEMA show W710's. Google it. Softer compound than the 710's.

Also Kumho is going to be changing the compound on the 710's (to keep up with Hoosier's?)

Hoosier did very well at this years Solo Nat's.