C4 Corvette Tire & Rim Size

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Arthur Grant
Posts: 1215
Joined: Sat Oct 03, 2009 8:13 pm
Club: TCC
Car#: 314

C4 Corvette Tire & Rim Size

Post by Arthur Grant »

During my run with Tom Berry, he commented on the size tires and wheels I should run on my 1990 C4 Corvette. Apparently he campaigned one very successfully some years ago. I have tired PMing however imagine he and the family are very busy getting the Evo rebuilt in time for the pro solo event. Any way this is open. I have a competition lowered 1990 C4 corvette. Am currently running 17x9.5 inch rims at all 4 corners shod with Kumho SPTs in 275 / 40 / 17. I am considering two options. One is to go to a larger wheel and tire on the rear of the car, the other is to go all the way and buy a race set with V710's.

I understand the stickier tires might be more fun, or they might just mask my driving deficiencies. I say this only because I know there is a lot of potential in the car with the stock set up. My best was a 93.2, George ran a relaxed (well teaching) 84.0. Tom ran a relaxed (well teaching) 80.4 after I had raised the rear tire pressure to 36 lbs (which appears to be the wrong direction) ergo I have at least 13 seconds of improvement available without doing a thing to the car. I do think larger rears would help tame the cars torque and balance up better. At this point I don't want to do anything that would move me out of BSP. I also don't want to do anything that will harm the body work. If I go with a larger rear wheel street tire set up I would likely just leave it on the car and save my current nearly new rears as replacement fronts.

I need to say I am not contending for championships, just trying to have fun and become a better driver. I was 16th at El Toro in the novice group, I am not delusional enough to believe I am going to buy magic equipment or tires that put me at #1 and win me a trophy. My goal at any event is to be better than the last event, and to improve each run with hopefully no DNF's. Better right now for me would be looking farther ahead, without suddenly getting surprised by the present.

Thanks for comments.
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George Schilling
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Re: C4 Corvette Tire & Rim Size

Post by George Schilling »

Take some time and work on the driver first. I'd suggest not making any changes yet until you determine where you fit in and what class you want to run. Then, build your car to the rules of that class. Don't put on "R" comps until you can handle street tires efficiently. Just my 2 cents.

-George
CASOC Autocross Club, 1984 Van Diemen RF-84, 1600cc Kent, Hewland Mk9, Centerline 2 pc. wheels, Hoosier R25B, SuperTrapp, Zimmer Alloclassic titanium left hip w/Metasul LDH chromium-cobalt lg dia head
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Will Kalman
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Car#: 232

Re: C4 Corvette Tire & Rim Size

Post by Will Kalman »

George Schilling wrote:Take some time and work on the driver first. I'd suggest not making any changes yet until you determine where you fit in and what class you want to run. Then, build your car to the rules of that class. Don't put on "R" comps until you can handle street tires efficiently. Just my 2 cents.

-George
+1 :thumbup:
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Steve Towers
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Car#: 87

Re: C4 Corvette Tire & Rim Size

Post by Steve Towers »

+2 :thumbup:
Giovanni Jaramillo
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Re: C4 Corvette Tire & Rim Size

Post by Giovanni Jaramillo »

Arthur Grant wrote:I understand the stickier tires might be more fun, or they might just mask my driving deficiencies.
That's EXACTLY what they'll do...mask the deficiencies like a "cloaking device" on a starship! :) Stick with the street tires, learn to feel the car sliding to correct and be on the edge. Improve the "nut" behind the wheel first and foremost.
Arthur Grant
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Re: C4 Corvette Tire & Rim Size

Post by Arthur Grant »

Since my front and rears are the same size, is worth going to wider rear tires. The ECSTAs aren't expensive and either are the wheels. Would still be the same street tire all around just not the same size at all four corners. George et all. Thank you very much for responding. Your input is highly valued.
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KJ Christopher
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Joined: Thu May 15, 2008 11:29 am
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Car#: 11
Location: Redondo Beach, CA

Re: C4 Corvette Tire & Rim Size

Post by KJ Christopher »

Arthur Grant wrote:Since my front and rears are the same size, is worth going to wider rear tires. The ECSTAs aren't expensive and either are the wheels. Would still be the same street tire all around just not the same size at all four corners. George et all. Thank you very much for responding. Your input is highly valued.
What are you trying to accomplish with the larger rear tire size? Other people went 10 seconds faster than you on the tires you currently have. I'd leave the tires alone and try to match their times. Get instructors at practices and championships. Get seat time.
kj
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Dan Shaw
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Location: Silicon Valley

Re: C4 Corvette Tire & Rim Size

Post by Dan Shaw »

EVo school FTW. +4 on improving your skills first. It's almost free and while you're setting up options you can make the most of the tire you have left. Get In for more practices and ask questions on better line options, taking slaloms, etc. Evo school improved my drivig tremendously. I ran times in the morning, and during our class it rained pretty hard. By the end of theday I was beating my dry times in te wet. That's at least a 3 second improvement.
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