PorschePower

I want to AX my '87 944S in a stock class this year. It has 15" wheels and the largest size all of the good AX tires come in for 15" wheels are 23" in diameter. That seems way too small, I think a 25" diameter tire would be more appropriate. Is anyone autocrossing their 944 with 15" wheels?

mikemyers924s

23" might make some sense...less contact patch but better acceleration.

JonH

I run the 225/45/15's for track and auto-x on the 924S, as mentioned the shorter dia. would only help accel for auto-x.

PorschePower

Can you post a picture of your car with that tire size on it? I'm curious what they look like on there.

JnJNY

Avon 225/45/15 r-compound tires... 15 x 7 phone dials.

1987 924s.

PorschePower

Is your car at a stock ride height or have you lowered it?

Arominus

The tires would lower the car due to the smaller diameter.

PorschePower

I know, but I am concerned about the extra space in the wheelwells due to the smaller diameter.

mikemyers924s

Are you concerned about performance or looks? From a purely performance standpoint, extra space won't do any harm of course. As for looks, the 944 has always had a fair bit of extra space in the wheel wells and I don't think it will make a substantial difference. If you are concerned about the way the big space looks, it might be time to start a thread on which wheels to choose! (I suggest 17" turbo twists).
I know the thread isn't specifically abut this, but the best tire I've seen for AX is the Falken Azeni. It comes in the correct size for cookie cutters and is an autocross killer.

Van

For max performance, go with the Hoosier A6 in a 15" size. Anything else - either brand or size - will compromise performance.

HICKS

Yeah, 17" turbo twist.

mikemyers924s

btw, I meant phone dials, not cookie cutters. Thanks for the pic @HICKS I have those wheels on mine as well (and love them), but your car is in much better shape paint-wise. Looks awesome!

M758

I race my 944 with 15" wheels. 225/50 R15. I also used to autocross a stock 83 944 with the same tire size. Great in stock class as it gives you a slightly lower final drive ratio and allows for shorter more reponsive side wall. Plus you lower the overal weight of wheel + tire.

They do look a little odd on stock height car, but so what. Do you want to be fast or look cool? If you want both get a second set of wheels.

PorschePower

Functionality is my main concern, I just didn't want it to look like I have skateboard wheels on the car. I was mostly concerned that the smaller diameter might cause something to scrape the ground or just simply not be enough tire for the car. From the picture and your responses I think I will run with the 15" wheels. I also have a set of 17" Cup II's, but that would put me in a modified class and I wanted to run the same tire size all the way around.

mikemyers924s

Cool, I don't think it'll look terribly out of the ordinary, and even if it does I think the functionality makes it worth it. Let us know which brand/model/size tires you end up running and how you like them!