Main Menu

1989 964 C4 Wheel Spacers on stock Design 90 wheels

Wheels and Tires

Vehicle Information: Year: 1989; Body Type: Coupe; Total Mileage: 144,370;

First...I want to thank you for your response to my previous questions! Here comes another one.My 1989 C4 has stock 16" design 90 wheels with a 6" by 52MM off-set on the front and 7" by 55MM off-set in the rear. Front tires are 205/55-16, Rear tires are 225/50-16 New Condition Nokia NRV's. My car is a weekend driver on fair Alaskan roads with many pot holes and frost heaves. I also participate in the Alaskan PCA autocross sessions held in the summer months.My first question deals with filling out those wheel wells on my car. (For example I love the look of a 911SC with the fuchs alloy wheels on the same size tires). Can I use wheel spacers to push out my current wheels giving a more cosmetic appeal? If so with the above information what sizes would you recommend? I am looking at the April issue of Panorama on page 19 there is an Ad for DRM series wheel spacers. I was looking at going with a 21MM spacer on the front and a 28MM or 32MM spacer on the rear.Will adding spacers damage other suspension parts such as wheel bearings or the all wheel drive system? Will I have any fender rub issues? I want them to fill out those wheel wells but not throw rocks down the side of my car.Would wheel spacers improve my autocross times? Would this combination reduce the understeer condition built into my car? Currently the only mod to the car is a Weltmeister tower strut brace. (Air box and Cup bypass will follow later this summer).I would like to keep the 16" wheels as they afford the most comfortable ride on our marginal road surfaces. The last part of my question deals with purchasing other wheels. Am I better served to go with a 17" Cup style wheel to get the cosmetic look (a filled wheel well) and would this be a better option for daily driving here in Alaska as well as for auto cross? Would I be better off purchasing another set of design 90 wheels putting the 7" on front with a 225/50-16 and a 8" on the rear of the car with a 245/45-16 tire mounted? What are the widest sizes that design 90 wheels come in? Should I run 8" wide design 90 wheels at all four corners with 225/50-16 on the front and 245/45-16 in the rear? Will this reduce understeer? How about 245/45-16 at all four corners?I have read all of the PCA technical posts and also those on rennlist and Johns 964 site for my car. It is hard for me to make a decision due to varying opinions and what seems to be conflicting information. Thanks for your insight in advance. I am excited to hear from you on this issue and am looking forward to our next Alaskan PCA autocross session. Summer is now arriving in Alaska.

You must log in to view answers associated with technical questions. Join PCA to participate in our community.
No votes yet