Silk

Anyone tried to fit Hoosier P325/30ZR19 A6 autocross rubber on a stock C6 rear rim (10x19)? The tire calls for a minimum 11" rim, but I've cheated an inch on some other cars with no problem. The diameter matches up fine with the stock tires, but the section width is quite a bit different - 11.4" stock, 13.6" on the Hoosiers. Thoughts?

Norm_427

I have the same frustration that you have, that no one is making a good sticky tire for the C6 rear. IMHO the 325 would be too wide for 10" as there would be too much buldge in the center of the tire and it would walk side to side on the wheel. Maybe my fears are exaggerated ... I'd like someone to mount it up and try it.

I haven't been able to get Hoosier to say IF or WHEN they'll make a tire for the 19"x10" C6.

Norm

aggie88

This is exactly the disappointing news I anticipated after autocross my Z51 for over 1 year. I have been on BFG KDW2s and gave those up for Nitto R2s in 18 inches all around.

http://www.hoosiertire.com/pb401706.HTM

Hoosier and Kumho never made a 18inch to fit the nonZ C5 either.

I think I will buy them and try to fit it on the 10 inch. It still must be better than anything else you can put on and stay in Super Stock.

XPC5R

I've run Hoosier's 335/18 on a 10.5" rim, while it's sidewall was noticeably squeezed, the carcass held the tread flat and square. The 325 should not be a problem. It's actually only 1/2" more tread than the old 305/18. The section width dimension looks large, but if you look at their specs, it's because it is measured ona a 13" rim!!

A squeezed is Hoosier is still way better than many other choices.

Silk

That's what I'm thinking. I'm running Pirelli P Zero Corsas right now, and while they're R compounds, they're really tracks tire and don't produce significant grip in autox. I'm going to see what the techs at Hoosier say about trying the 325s on a 10" rim and then make a decision.

One other thought - Hoosier also has a P315/40ZR19 A6 which would fit on a 10" rim - but the diameter is about 2" larger than stock. Assuming there are no clearance issues (and I'm not even sure that's the case), would it be a mistake to try this?

John Shiels

will change gearing

aggie88

It will, but with the power of the C6, it may not be too much of a penalty. But, more of a concern for me is that it would considerably change the rake of the car. I heard some chatter about too much differential between front and rear tire revolutions may cause problems, but don't know if that affects competition mode.

Norm_427

That tire is intended for the Ford GT and it is very tall in order to have that retro 1960s look. I believe it would be a big mistake to put that on the C6 as your rear would be too high -- and the gearing would suck.

XPC5R

Lots of guys run the Kumho 315/18, it is a similar diameter (26.4"). Your gearing will get reduced slightly, but the C6 is not short on power anyway. Many think it makes the cars easier to drive, as you may be able to put down power more easily.

Rickard

I just bought the new Falken Azenis RT-615 tires for the track. They just came out with a 295/40-18 which is only about .4" off in overall diameter for the rear. Best of all, they are relatively cheap at $240 each. If you shop, you may find them cheaper.

Check Vulcan tire.