Go bigger in the back? Wheels for the track.
07-09-2007, 05:46 PM
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Go bigger in the back? Wheels for the track.
I dinged two of the lips on my CCW's, and they are currently 17x11 front and back using 315/35/17's. 
Now my dilema, should I go from a 2.5" lip to 3 or 3.5" and convert the rear to either 11.5 or 12" wide?
There are not many tires wider than 315 for a 17" wheel anyway, but I may get a better contact with the extra 0.5-1" wheel back there. Any experience or input?
Now my dilema, should I go from a 2.5" lip to 3 or 3.5" and convert the rear to either 11.5 or 12" wide?
There are not many tires wider than 315 for a 17" wheel anyway, but I may get a better contact with the extra 0.5-1" wheel back there. Any experience or input?
07-09-2007, 07:50 PM
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I don't remember off the top of my head when GM changed the rear configuration on the C4...
I do know that with the proper back-space and ZR1 fenders you can fit 345's inside the wheel wells.
I had John @ CCW build me a set of 18" rims for mine. It was getting so difficult to get 17" rubber for the track, but 18" rubber was readily available.
With 18 x 11's, I can get a 29.5" x 12" on the rear of my C4...maximum you can have INSIDE the fender lips.
I do know that with the proper back-space and ZR1 fenders you can fit 345's inside the wheel wells.
I had John @ CCW build me a set of 18" rims for mine. It was getting so difficult to get 17" rubber for the track, but 18" rubber was readily available.
With 18 x 11's, I can get a 29.5" x 12" on the rear of my C4...maximum you can have INSIDE the fender lips.
07-10-2007, 01:07 PM
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Ya, the only wider size for 17" wheels is 335/35/17 that would change my gearing slightly... and they're $400+ per tire 
. I think I'm just going to stick with 17x11 for the simple fact that I know it works already.
I meant the real track, not the straight line
My main concern is that the big old corvette pushes at autocrosses, and I would like it to oversteer a little more. Probably negligable either way.
. I think I'm just going to stick with 17x11 for the simple fact that I know it works already.I meant the real track, not the straight line
My main concern is that the big old corvette pushes at autocrosses, and I would like it to oversteer a little more. Probably negligable either way.
07-12-2007, 12:23 AM
#6
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Well, if you want it to OVERSTEER more, you would actually want LESS tire in the rear, or MORE tire in the front. Having a wider tire in the rear will increase rear traction, causing more push in the front.
DaveZ.
DaveZ.
07-12-2007, 08:54 AM
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I run a 12" tire in back and an 11.5" tire in front. The 11.5" tire is the widest that fits without rubbing on the sway bars and control arms. With an aggressive alignment, mine turns on a dime.
I have them max out the caster, zero deg.toe and -3/4 camber...makes the car twitchy and on the edge all the time.
07-12-2007, 05:54 PM
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You guys are right, I don't know what the hell I was thinking about the understeer/oversteer differences. I kept it at 11" all around anyway, and I should have the new lips in a week to start pulling apart my wheels.
I run a 12" tire in back and an 11.5" tire in front. The 11.5" tire is the widest that fits without rubbing on the sway bars and control arms. With an aggressive alignment, mine turns on a dime.
I have them max out the caster, zero deg.toe and -3/4 camber...makes the car twitchy and on the edge all the time.
How do you fit the 11.5" up front without rubbing the sway bar? My wheels actually touch and I would like to figure out a solution.
I run a 12" tire in back and an 11.5" tire in front. The 11.5" tire is the widest that fits without rubbing on the sway bars and control arms. With an aggressive alignment, mine turns on a dime.
I have them max out the caster, zero deg.toe and -3/4 camber...makes the car twitchy and on the edge all the time.
How do you fit the 11.5" up front without rubbing the sway bar? My wheels actually touch and I would like to figure out a solution.
07-12-2007, 07:20 PM
#9
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You guys are right, I don't know what the hell I was thinking about the understeer/oversteer differences. I kept it at 11" all around anyway, and I should have the new lips in a week to start pulling apart my wheels.
How do you fit the 11.5" up front without rubbing the sway bar? My wheels actually touch and I would like to figure out a solution.
How do you fit the 11.5" up front without rubbing the sway bar? My wheels actually touch and I would like to figure out a solution.
What we did was set all 4 for the front back-space, then I use a 1/4" spacer on the rears to get them in the right place. If I go full lock, and the suspension is in load it scrapes a bit on the sway bar. (The difference could be the overall diameter of my 18" rims to your 17" rims as well....John could tell you).
I always try to ensure that I never need to go full-lock at the track/autocross...I figure out how to make it smoother.