Brian W.

Hello everybody. Im new to the forums but not so new to Porsches.

Name is Brian obviously and my father and i own an 87 911 turbo look, and we recently acquired a 91 911 turbo.

My question is what the widest wheel and tire setup i can fit under the car. Ive been doing a lot of searching and research. I dont mind rolling or trimming fenders at all as this car will be strictly for track use. A set of wheels i am interested in come in the following size:

Front 18x8.5 +50
Rear 18x10.5 +40

I have a feeling with the proper camber and alignment settings dialed in that we could fit either a wider wheel or lower offset in but this is all speculation.

I look forawrd to your suggestions.

The Suspension we will most likely be using is Moton ClubSports.

Thanks in advance!......

jetskied

Not sure about the offset on 964turbo, but I have thoes same size wheels on a '78 930 so I'm sure thoes wheels would fit if they are the propper offset. I did not have to roll the fender or any other modification to make it work. BTW I use 225/40 and 285/30 tires.

JBH

You might be able to get a 235 tire in the front, but I am afraid 285 is going to be the limit in the rear without some big mods.

I started chasing this same question. Here are the links to those discussions:
Trailing Arm Modifications

Widest wheel and tire

For more information, use "wheels" in the Rennlist search option for the 964 turbo forum.

Some people believe a 295 tire in the rear is possible, but I suggest you try to find people that have successfully run like that on the track lap after lap before you commit to it.

I am still trying to find someone who made the switch to the C2 trailing arm and drove the car with a larger wheel/tire combination on the track. That seems to me to be the trick setup if it works.

964turbo

The rear will not fit, the offset is too far out.
I tried the offset before and it was sticking
out of the fender. You will need 55 or 60
offset. And the front might touch the liner
when you do the lock turn.

Brian W.

Its odd you say... these wont fit. As these wheels are designed FOR the 964 Turbo.

Ive read alot about the trailing arm modification, but id like to stay away from that as i dont need THAT big of a wheel.

Anyone have wheels on 964 turbos that they wouldnt mind sharing size, offset, and pictures of?

Does anyone know the factory size and offset ?

Thanks again!

Brian W.

Actually i also searched through the C2Turbo forums... but no one has any concrete info... The C2Turbo fella states that the sizes i have picked out are correct... However.... no one says anything about Offsets......

jeff91C2T

There's a local guy here running 305's (18" hoosiers) on a 91 Turbo. So it can be done...but with work. This particular car was running a LOT of negative camber. This was primarily a track car. I've also got a friend running 295's (on 19's in the rear) with no clearance issues.

I put on a 275/40 17" tire on the front to "see how it looks". The wheel offstet (I believe) was a 52. With the wheels pointing straight, it looked good. Tucked in real nice under the fender. But turn the wheel....forget it. The inner tire comes into major contact with the fender liner. BUT...I think with some rework to the liner, it might be possible. I'm running linear H&R springs (small diameter) so this allows a larger amount of tire. Before, with the larger diameter spings, this wasn't possible.

What might be a nice wheel size package...for me anyway, will be to pick up a set of 996 rear Carrera 5 spoke wheels off a 996 (18x10) for the rear and a pair off the rear of a boxter (18x9). I think this would be the most cost effective max rim size package. I looked at doing Kenesis/Fikse and it was just too much money (for me ;-)

Brian W.

So.....

Im thinking ill jsut get these sizes and offsets that i had mentioned above, and make them fit the car, via Camber and fender trim if nessecary.....