So I'm talking to tom'z wheels in belton (about 30 minutes north of me). I'm wanting to get a set of 18's all the way around and I'm thinking I can go 1" wider on the wheels.

18x9.5 - front
18x11 - rear

These will be cast, but I'm not wanting to spend 5k on wheels that I'll use on the track. Keep in mind there isn't any car2car contact in most cases. I want to move to a better tire for the track days.

Ideally I'd want 275/285 on the front and 315's on the rear. Anyone who feels like posting want to make a comment or suggestion! Thanks and happy driving!

JK

 

I am getting some OEM fronts widened for DR's. There is a thread called Rim Widening for progress report. Right now they are at the widening shop.

 

There are guys that run 18 X 10.5s all around with Kumho 710s 315 F/R

 

Were can you get the 18 x 10.5? and what do they look like?

Thanks!

 

Is there a benefit to having the rears and the fronts the same size? For example you have them both at 18"

 

Keep your front outside diameter 1 in less than your rear outside diameter or Active Handling will throw codes and reduce power.

 

Even with the AH/TC turned OFF?

 

Also, ALL 18 x10.5 Corvette C5 / C6 style wheels currently made are in C5 offset and will stick out beyond the rear fender on the C6. Yes, this applies even to the "C6" style wheels. It is a totally stupid situation, but there you have it.

Also, I am not sure a 18x10.5 will fit on the front. I know 18x9.5 works just fine and fits flush with the fender.

Also, if you add the same amount of rubber up front as in the rear, you will increase the car's tendency to oversteer. Don't know about you, but IMO, the last thing the C6 needs is more oversteer. If you want to maintain the same handling character, you need to keep your size stagger the same.

Finally, TC on the C6 cannot handle less than a 1 inch differential. It WILL come on and you will have to shut it off. The good news is that the car did not go into "reduced power" and I was able to keep AH and Comp Mode.

If you want track tires at minimum cost, the best solution is to get C5 repros 17x8.5 front and 18x9.5 rear, and fit them with Nitto NT-01/ Toyo RA-1s (same tire, basically) in 235/40-17 front and 275/35-18. You will maintain both your wheel diameter differential as well as your size stagger and handling character. You will have more than enough grip despite the smaller tire, and you save much $$$.

 

Call John at Complete Custom Wheels (CCW) in Florida and he has good wheels for the C6 with proper offset: 18x10 Front and 18x11 Rear. He's very familiar with C6 wheels for track use and I'm about to order a set myself. His "Classic" line of wheels are 3 piece and they go for about $2,000.

http://www.ccwheel.com/files/home.php

Norm

 

I don't think the 17" wheels on the front will clear the brakes -- I tried a 17" that I had laying around and no go ... 18" on the rear will clear the brakes.

 

Yes

 

Is this something that you have personally experienced? The reason I'm asking is because I have read conflicting accounts of this phenomenon. It seems logical that if the AH / TC is turned OFF that the computer would leave you alone. ?

Thanks.

 

This is bull****, I have 18's on the front of my car now and 17 inch drag radials from my c5 on the back, no codes. I also ran four 17's on the car for several days with no problems. I run 17 inch DR's on the back sometimes with 17's on the front and sometimes with 18's on the front.

 

Your first paragraph is also crap, you want to see my C5 size C6 replica wheels in 18x10 on the back of my C6? They dont stick out at all.

 

The 17's fit on the front of mine no problem, if you go full turn locked up they just touch the nut on the outer tie rod end. This was only on full lock with the pump making noise, like you should'nt do anyway.

 

Is this a situation in which you are competing? If so, are you trying to stay in a stock class? Changing tire/wheel size (even smaller) will knock you out of stock under most rules that I have seen.

 

Tried this in the autocross section with no response, so I'll try here as well...

I'm looking into changing out tires for autocross. Already have headers and air box so I'm into group II (NCCC) and definately need tires to be competitive. Since in group II anyway doesn't matter if I switch wheel size....

Everyone around here is running Kumho's, so it looks to me like my best bet is 275/40-17 front and 315/35-18 rear. From Cucchiara's post I'm more or less getting that this will fit with some offset or another. Note that I've lowered the rear as far as the stock bolts allow and then dropped the front just a bit to look "right".

Any suggestions for cheap, track-only wheels? Don't care in the least if they stick out some, etc. - just so that they're wide enough (9.0-11.0 front and 10.5-12.5 rear), have offsets that keep everything from rubbing with the tires listed above and don't weigh too much. I'd guess wider is better as long as they don't rub in order to minimize sidewall flex.

Thanks for any advice.

 

I am getting two OEM front widened two inches and plan to use a spacer to move them out to the proper position. I just need these for drag radials.

You can pick up some OEM fronts for about 150 plus shipping and it costs 200 to have the wheel professionally widened.

Or buy the entire set (4) of OEM painted front wheels for 400 or so plus shipping. Then widen the rears and use spacers to fix the offset and you would have 18x8.5's on the front and up to an 18x10.5 in the rear.

Another OEM wheel option would be just run 18x8.5 inch wheels all around with spacers in the rear. You could probably squeeze a 275 series tire all around and be in descent shape.

Of course just to clarify I am talking about track tires and wheels here.

 

Just my .02 but I think your nuts running a spacer in any kind of a race situation! Do you know how often these things break? Are you using a bolt on spacer or a slip on spacer? If your using a slip on spacer are you using stock studs or race studs? Some of the new billet spacers are the best you can get compered to the old school garbage people used to run but I have seen ALOT of broken spacers in my 18 years as a tech and that was just with street use. Stay safe

 

I'm guessing you have the Z51 brakes then. If you use the smaller rotors from the base/F55 packages then a 17'' will fit. That is the same rotor and caliper as the C5 Z06 and it has 17'' wheels in front.