Cup 1s - Tire size question
#1
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I just bought a very nice set of refinished Cup 1 wheels from a fellow Rennlister. The Dunlop Star Spec Z1s that came on the wheels are good for a few thousand more miles but I'm starting to think about replacements.
Current sizes are: 235/40/17 front and 265/40/17 rear. Are these the preferred tire sizes for these wheels or does the board have other suggestions? Thanks for any help!
Current sizes are: 235/40/17 front and 265/40/17 rear. Are these the preferred tire sizes for these wheels or does the board have other suggestions? Thanks for any help!
#6
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Chris:
Street - no track. While I would be interested in any suggestions regarding tires, my real question goes to the optimum size.
Rears are 9". Can't read width and offset on the fronts due to refinish/powercoat and don't feel like pulling a wheel to confirm but I'm pretty sure they are 8".
Street - no track. While I would be interested in any suggestions regarding tires, my real question goes to the optimum size.
Rears are 9". Can't read width and offset on the fronts due to refinish/powercoat and don't feel like pulling a wheel to confirm but I'm pretty sure they are 8".
Last edited by gray635; 09-02-2013 at 01:50 PM.
#7
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Chris:
Street - no track. While I would be interested in any suggestions regarding tires, my real question goes to the optimum size.
Rears are 9". Can't read width and offset on the fronts due to refinish/powercoat and don't feel like pulling a wheel to confirm but I'm pretty sure they are 8".
Street - no track. While I would be interested in any suggestions regarding tires, my real question goes to the optimum size.
Rears are 9". Can't read width and offset on the fronts due to refinish/powercoat and don't feel like pulling a wheel to confirm but I'm pretty sure they are 8".
If they are replicas, the fronts may be 7 1/2. My road wheels are 17" Mille Miglia Cup 1 replicas which came in 7 1/2 and 9. That is based on what came on the Carrera RS.
As Earlydays said, 205/255 are the factory recommendations for those size wheels on a non-turbo, narrow body C2. I run those on the street, and even with a 7mm front spacer, I still get a little rubbing at full lock on the inner wheel well.
If you are not going to track the car, there is no reason to go beyond 205/255, as that is what Porsche considers "optimum".
FYI, there is a Porsche Tech Service Bulletin #4440. The one I have is dated 5/2003. That is where I found the preceding information. All the approved fitments for all 964's are covered; turbo and non-turbo.
Brian
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#13
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I know you're talking about doing a street tire, but my car allows for 245/17 front, 275/17 rear using 8" front wheels (formerly on the rear of my car) and 9" turbo wheels on the rear. Tires are Hoosier R6, and i use a small spacer in the rear (6mm or so). You may need to roll your fenders/quarters, though.