divil

I'm looking for suggestions/advice on wheels and tires for mostly street and occasional track use. I noticed that my rear tires are starting to show cracks so it's time to replace them. I have the original 16x9 and 16x7 Turbo S CS wheels. I'm tempted to change the wheels to try a square setup because I've always thought I could use a bit more grip in the front. It might also be nice to have 17" wheels since that would give me more choices for tires, but then it might also make the car a bit more harsh. So far, I'm considering these options:

* stick with the stock set up (this will be really cheap because my front tires are ok)
* get a pair of rear 16" CS wheels to go on the front for a square setup
* get a full set of 17" wheels with the same stagger I have now (9" and 7")
* get a full set of 17" wheels in 8.5 or 9"

It seems to be really hard to find a set of 4 17" Porsche rims in the same widths. It's easy to find them with the typical stagger though. But in any case, I'm not sure where I'll end up with offsets. I believe the stock Turbo S offsets are 65 and 60. If I get wheels with less than that, that means they'll stick out further, and there's no fix for that, correct?

It takes me a long time to get through a set of tires so I will probably be stuck with whatever I do for a while.

What would you do?

87944turbo

I am pretty happy with my square setup of 8.5" wide twists. They could use some spacers to push them out some more, it's just not something I have ever gotten around to doing.

You're right about the tire choices for 17s. I have a set of turbo S wheels as well and have found the tire choice pretty limited. More choice equals better prices too, generally speaking. I just picked up another set of 18in wheels recently, so I really need to move a set out of the garage. Looks like your local, maybe we can work something out.

Chapman951

What are your road conditions when daily driving?

Do you drive the car slow on the streets or go on spirited runs?

divil

Road conditions, bad. Really bad. But it seems to be like that everywhere.

I do both ordinary driving and spirited driving, as circumstances allow.

Chapman951

I’m not sure if my phone dails are 15” or 16” but I’m running some Continental extremes. The roads up here in Arcata, California can be pretty severe if you are no longer on the freeways. These do a great job absorbing the bigger holes and I’m pleased with the ride quality.
I’m running some Weltmeister front and rear sway bars and front Welt springs and can not complain for a great handling daily driver. Track events when the cars ready :-)

951and944S

16 or 17" square setup.
You can get a 17" tire that has virtually the same rolling diameter as the 16" so gearing is not a concern.
Either allows you to move the tires around the car to get most life (some tracks are heavily biased towards LF wear etc.)
Having non staggered set makes a good baseline for balancing handling and makes learning what/when to change something much more apparent and consistent.

T

Flea3

I’ll save you some aggravation. 16X9 Street? Pirelli. That’s it.

divil

I sent you a PM, but I suspect it didn't show up because that seems to be happening lately. Let me know!

jimbo1111

On my two previous 86 cars I ran 225/50/16 up front and 245/45/16 in the rear. This time I'm sticking to the stock sizes on the Fuchs wheels. I found the bulging out of the wider rubber affects the overall appearance negatively. If your going to do it, you will probably need custom wheels.

divil

Those are exactly the stock sizes for the wheels I have.

jimbo1111

My car is an 86 and came with 205 in the front 225 in the rear. The original tires are still on the car in fact.

divil

I just tried fitting my rear 9" wheels on the front to see if there would be any issues. For some reason on the front passenger side the wheel rubs against the spring a little, but it seems to be only in one place in it's rotation.

It has actually scraped the paint on the spring (2 horizontal lines between the 2 rust spots in this pic):




Has anyone else run into this issue? I don't have excessive negative camber or runout. I didn't try lowering the car with this wheel on the front but I presume the problem would be worse with the suspension compressed, right?

MAGK944

The rears are the wrong offset for the front, that combined with the added width means they won’t fit. You may be able to make them fit with a small spacer.

divil

Yes I knew I had read about other people doing it but now that I look closer it seems most of them either have smaller diameter springs or use spacers (https://rennlist.com/forums/924-931-...the-front.html)

Does anyone know if the clearance between the rim and the spring gets bigger or smaller when the suspension is extended fully (wheels off the ground)? What I'm concerned about is, if I get the wheel to fit with enough clearance when the car is off the ground, is it still possible it could rub at normal ride height or under compression?

MAGK944

Yes the wheel will articulate differently when in the air, on the ground or under compression, your camber will also play a big part.

Curious why you don’t just fit wheel and tire sizes that are proven to work with our cars? It’s all been done before a zillion times.