Tire and wheel installation

The first upgrade has to be tires and wheels. So it’s off with the old and on with some more serious rubber. Using the widest size allowed by the class rules, we’ve installed 255/40R17 Dunlop Direzza Sport Z1 Star Spec tires mounted on 17x9.0 ET48 TRMotorsports C3 wheels. This is a very aggressive custom fitment, which required some work to get to fit. The white chalk mark seen in the photos is to check for any tire interference with the bodywork of the car. It was worth the effort to make it fit, and boy it sure looks good! We can’t wait to see how well it works out on the test track.


Thursday, April 1, 2010 by Joe

Looking for advice on tires for 1999 Boxster. The Wheels are cast alloy 7Jx17 front, and 8.5Jx17 rear. The tires are 205/50ZR17 front and 255/40/ZR17 rear. Will 255/40-17 tires front and 275/40-17 rear fit stock wheels. What is the diff? in these tire sizes? Looking at Dunlap Z1 or Contl DW's.
Thursday, April 1, 2010 by Tire Rack Motorsports

Joe: Unfortunately, the sizes you're considering are too wide for the OE Porsche wheels. There is also significant concern of rubbing both front and rear even if they did fit your wheels. I would recommend using 225/45R17 in the front and 255/40R17 in the rear. They have the proper overall diameter, work with your wheels, fit the car nicely, and the wider-than-OE sizes should offer a noticeably wider footprint. If you are considering moving away from Porsche-approved N-spec tires, the Dunlop Direzza Sport Z1 Star Spec is available in these sizes.
Friday, June 18, 2010 by Chris

I have an 06 MX5 and have the C3s 17 x 9s in black with Sumitomo ZRIIs in 255/40. Besides rolling the fenders what re-alignment should be done that can bring the camber in a little. I have eibach springs. Oh and does it matter if it was specified as the RX8 because this wheel doesn't show under the stock Mx5 listing

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