99hawk409

I thought that i'd simply be able to hit tire rack for my tires but there are no competition tires in the stock sizes.

What sizes will fit safely onto the stock rims? I'm looking to stay in the
stock class hence the stock rim sizing.

THanks!

99hawk409

ttt anybody?

thanks!

VetteDrmr

I'm running 275/305 Toyo RA-1s on stock wagon wheels. They work just fine, tire wear is as even as anyone else, and my alignment settings are basically Z06 settings.

HTH, and have a good one,
Mike

UstaB-GS549

It would help to know what your stock wheel sizes are.

VetteDrmr

17x8.5/18x9.5

68sixspeed

VetteDrmr-- very cool info, thanks for the post... I've been debating on getting z06 rims for the extra width, but this saves some $$! No problems them with fitting on the narrower rim? Or body rubs?

How do you like the toyo's?? I've never run them before, curious how they compare to the NT01's, and others?

thanks!

Dan

VetteDrmr

I've not run the NT01s, although Nitto and Toyo are made by the same company; my guess is they'll be fairly close. As far as fitting on the narrower rims, I've never had my tire mounters complain and I always tip them for the work done.

No body rubs at all. Just fat meaty tires on cheap strong rims!

Have a good one,
Mike

VetteDrmr

BTW, I'd look for a set of wagon wheels for those tires. You can get them for virtually free and they're quite a bit stronger than the thin-spoke '00 rims.

68sixspeed

thanks. I was actually thinking of using the stock magnesium rims that came with my c5... they have some bald run flats on them still. Plus they should be light.

VetteDrmr

They are light, but I *really* would be cautious with using mags. You have to worry about the clear coat getting scuffed and the alloy oxidizing, and I haven't heard of much experience with them from a bending/cracking point of view.

Not saying they won't work, and work well, but they are a bit of an unknown.

Have a good one,
Mike

99hawk409

Thanks for the info...i'd love to get a set of race tires/wheels asap for the coming season. Wagon wheels sure can be had CHEAP!

They are fairly ugly but somebody on this forum was selling some black wagon wheels with a red lip, i believe. They looked great! (winter project!)

Thanks again for the info...i'll probably be sticking with the tried and true Kumho brand. I loved the victoracers just for the longevity!

robvuk

Your stock FRC rims come with 245/275's. The Z06 came with 275/295's, basically one size larger. They work fine on the FRC rims and the Z06 size tires are plentiful.

VetteDrmr

Ugly wheels are perfect for tracking because you don't worry about brake dust, rubber gobs, etc.

Gordy M

If you are autocrossing and want to stay in SS or IH class then Hoosier 275/40/17 fronts and 295/30/18 rears work very well. If you take that set up to the track, it is important that you check the "rake" of the car for better handling. That is basically a square set up.

If you are new to autocrossing on competition tires, then another tip would be short shifting into 2nd for most of your events. The Toyo's and Nitto's will last longer but the Hoosier A6 and the Kumho V710's are considerably faster.

blue Z06+

Gordy M will the above Hoosier sizes affect the active handling since the rears are shorter than the fronts? What is the rake? How do you check it?

Thanks

Gordy M

Rake is the ride height of the rear wheels and the front wheels. The easiest way to measure is at the jacking points, you want the front point at least 1/4-3/8" lower that the back. When I run autocrosses, I turn the active handling off, when Time trials/HPDE I usually run in competition mode. Active handling still works with a 275/295 set up.

Also you will have to consider a compromise on the alignment. For a double duty car you want about 1.2 to 1.5 neg camber in the front and about 0.7 rear. 0 toe and all the caster you can get--balance the caster. Rear toe about 1/16 toe in.