I recently upgraded to S4 brakes in the front, and had plenty of clearance with my 17" street wheels. But when I tried to put my original eqmt 16" Phone Dials with my track tires on today, the wheels aren't clearing the S4 calipers.

I thought the S4 brakes were supposed to fit under 16" Phone Dials? Anyone know if I can make them fit with a spacer, or am I going to have to get different wheels for the track? The reason I went with the S4 brakes instead of Big Reds was so I could use the wheels I've already got.

 

Where exactly are they hitting? Face or rim of the caliper?

Sam

 

They are hitting the outer face of the caliper. I noticed my front PD's have a small inward-pointing flange on the inside of some of the spokes, and it looks like this is what is hitting against the caliper. The rear PD's don't have anything like that.

 

What year car is this? I believe your problem is due to offset, run a small spacer and it'll clear fine.

Sam

 

It's an early '88 model -- built in July 87. I'm hoping a spacer will do the trick, I just didn't expect this problem at all. Unfortunately, I'm heading off to VIR tomorrow for a two day event, and at this late stage I'm going to have to just run with my 17" street wheels and tires -- Kumho Ecsta 712's which leave a LOT to be desired compared to my normal RA-1 track tires.

 

Ecsta 712's leave a lot to be desired compared to ANY tire! But, perhaps I'm a bit jaded.

I used 8mm spacers up front whith S4 brakes and a set of design 90 wheels. Same problem with it not clearing the caliper face, but cleared radially just fine. With stock studs, the steel nuts I used held fine though miles of flogging but will only grab half the threads available to the nuts so tech will def. not pass you. I wouldnt even though I know mine held.

 

You have to run 8" rear rims up front. The factory 7" front rims won't clear without spacers.

Regards,

 

The S4 brakes installed on the new 88 turbo S were fit with the new (porsche)
Turbo S wheels that was specifically designed for the clearance of those brakes
At that time is was the only wheel that would clear those brakes other than the 928 dish wheels .....
and of course the Mg cup wheels ..... So, I don't think the phone dials
from what I have heard were ever meant to clear those brakes....
Good luck
Ed

 

Assuming the set of front D90 wheels you used are 7" wide, would 7 mm spacers be wide enough too ?
I can't seem to find spacers sized between 7 mm and 15 mm ...

 

Let me add to this discussion that if you have an early offset car (86) and add S4 calipers (with adapters and custom rotors), 7" 86 951 Phone Dials DO clear the calipers with no problems. So do 7" 86 951 Fuchs.

 

So here's a related question.

Does anyone know if early offset 8" phone dials would clear Big Reds? With spacers, without, not under any circumstances, etc...

I'm trying to keep my car as stock looking as possible.

 

It won't answer your question but for having tried, late offset 8" phone dials (rear wheels, then) do not clear 928 S4/turbo S calipers.

 

They do not?? Ive run 8" phonedials on the front of my Turbo S for years.

 

Big Reds require 17" wheels. Phone dials only come in 15" and 16".

You'll note that the 88 non-S was the last 951 to come with phone dials.

The 928S4 brakes are not the same Big Reds. 928GTS big Blacks ARE, as far as I know, the same as big reds. And they do require 17" wheels.

 

Which offset of phone dials have you used ?
The late offset 8" PD wheels we tried at the front of a turbo S did NOT clear the calipers because of a too low offset. It might have worked if we had used spacers, but we did not try.

'89 turbo Cup came with phone dials