rfuerst

Hello,I have a 1983-911SC that has the factory Fuchs wheels in the 16 inch size,I am not sure of the width,the sticker in the engine bay plus the owners manual states that the fronts are 205/55-16 and the rear is 225/50-16.The car currently has 205/55-16 front and 245/45-16 on the rear,any thought on this size combo?I currently am useing the car as a fair weather driver but may do some auto-cross or DE in the future,any suggestions are appreciated.Thanks and happy holidays!!! <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Bill Gregory

If you have the stock rims on, you have 6x16's on the front and 7x16's on the rear. The 205's are fine on the front, however, the 245's are too big for the 7" rims. I just checked tire rack, and each 245/45x16 tire's minimum size was 7.5". When you have that much larger rubber on the rear than the front, you increase the chances for understeer. Assuming you have 7's in the rear (it will tell you on the back of the Fuchs paddle), I would put the same brand tire on as you have in front, in the stock 225 size, certainly before taking it on the track.

You may have already read the 911SC FAQ on tech.rennlist.com, where wheel and tire sizes are covered. Bruce Anderson also has discussion in his "Porsche 911 Performance Handbook"

rfuerst

Thanks for the reply,I went out to the garage and did a rough measurement with a tape measure and it looks like the fronts are 7 inch and the rears are 8 inch,is that possible?Were these sizes a option?Thanks and Happy Holidays!!!! <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Bill Gregory

Take a front/rear wheel off and read the back of the paddle where the size will be embedded in the metal. The standard wheels on an SC were 15", with the 6x16 and 7x16 being the optional wheels. Many came with the 16" wheels.

I ran 7's and 8's at the track with stock tire sizes (larger rims pushes the sidewalls out and stiffens them up) for awhile, then went to 944 8's and 9's with 225's and 245's.