Tyre size for 17" cups on Carrera 3.2

Bought a set of replica 17" Cup 1 alloys , with offset for early 911 3.2

Front wheels 7.5Jx17H2 ET23 215/45/ZR17

Rear wheels 9Jx17H2 ET15 255/40/ZR17


want to fit these to a standard bodied Carrera 3.2

Will there be enough clearance to fit them with the larger rear tyres ( 255 / 40 ) or will I need to fit the slightly narrower 235 tyres?


Thanks for any help.

It varies from car to car and depends on the condition of your torsion bars/shocks. Plus of course ride hight.

But in general it should be possible to fit those wheels. I had slight problems with my car which was lowered. I had the same wheels and tires except for having 245/40 at the rear instead of 255/40.

[Hendog]

I'm running the same size in the back and 205/50/17 if front. I'm going to be changing rubber soon and will putting 215 in the front because Falken doesn't make a 205/50/17. Here's a link to a site which has a Tire size calcualtor and comparator. It's under "online interactive tools" on the right hand side of the page. http://www.discountpartcenter.com/

Hope this helps.

[sewell94]

On the rear, Juan Ruiz is running 275's on the twists and 255's(i believe) his carrera cups. He has a narrow body carrera.

I've fitted the wheels on now

Front wheels 7.5Jx17H2 ET23 215/45/ZR17
Rear wheels 9Jx17H2 ET15 255/40/ZR17

- and been for a few long runs, twisting roads at good speed, and there seems to be plenty of clearance, no nasty ( expensive ) rubbing noises!

[jpachard]

I can run 245/45 in the front and 275/40 in th rear(Hoosiers) this is on 8 and 9" rims. 225 and 255 would be a perfect choice if available in your tire brand of choice.

Cheers, James

[ted]

Originally posted by Oxford_Hippo
Will there be enough clearance to fit them with the larger rear tyres ( 255 / 40 ) or will I need to fit the slightly narrower 235 tyres?

I just reread your post, were you considering 235 rears?
I have 275/40 rears with the oil line relocated and fenders rolled.
I'll leave my reply just in case you decide to super size someday.

With a 7.5 front rim I'd go with the 235/40/17.

I have fit the Victoracer 255/40 front with 17x8.5 front rims on my early 911 with RS rear flares. I had -2.7 camber, torsion bars, car sat a little high. fenders were rolled and the shock dust covers removed. At the track there would always be one turn that would with over half a tank or if I had a passenger the fronts would rub the fenders. It did not rub on the street with a full tank and a passenger.

On the track I had 255/40/17 fronts and 275/40/17 rears. The car was balanced very well. My front tire temps though would never get hot enough, the large front tires were not working hard enough. Such is the case with 911s that the front tire temps may be 20 to 30 degrees cooler than the rear tires due to the rear engine. In my case the fronts were still not hot enough.

Since then I have gone to 235/40/17 fronts 275/40/17 rears and lowered the car a good inch all around and put a little forward rake in it as well. The lower ride height /CG would not have been possible with the larger 255/40/17 fronts. Unless I went widebody??
Given the choice for a front tire I would take a 225/40/17 Victoracer over the 255/40/17. At the moment I'm trying the RA-1 235/40/17/275/40/17 tires.

First pic with 255/40/17 fronts and the second with 235/40/17 fronts.

235/40/17 RA-1 fronts below,