I've been using 8" phone dials with S4 calipers up front for years on my '86. They're very close, but they work. 7" phone dials will not work with S4 calipers. That's why 8" phone dials are at a premium, although the 7's are popular in Spec 944, so maybe you could work out a deal from two sets of PD's with a Spec 944 driver. Or get two 8" phone dials.

 

Are you sure it wasnt a 7"?

Late offset (52mm) phone dials fit on 88-89 Turbo (S) cars just fine. Ive used various 8" phone dials (I have 13 of them for track wheels) on two different 89 Turbos and never have had any clearance problems.

Sure, as well as the 944S2 Club Sports thru '91, but those were not production cars and those wheels (8 and 9x16 magnesium) are very rare and expensive.

 

Well, it really was 8" late offset phone dials, as originally seen at the rear of 87&88 turbo 220 bhp.
Strange ...

 

I question whether BR's require 17" wheels because I've done some quick and dirty measuring of the rotor diameter+caliper and it seems it will clear the interior of an 8" early offset phone dial but I've yet to actually try it.

I don't think anyone here is confusing S4 brakes with BR's. But if you measure S4's and BR's...they're not far off in terms of dimensions. If you measure the needed inside diameter of a BR brake setup, it's right on the line of fitting within an early offset 8" phonedial.

Hence the question. So has anyone ever tried?

 

But why then would every vendor tell me I need 17's to fit big reds?

 

Because almost any 17" wheel will fit over Big Reds and few 16" wheels will.

Vendors are not going to bother figuring out what rare 16" wheel will fit. Even among 17" wheels there are a few that won't fit over BR's but those are few and far between. Vendors also put out erroneous information sometimes as well (300rwhp limit to turbo tranny's comes to mind).

Take a look at this very discussion. Common wisdom is that S4 brakes should fit under 16X8 wheels but there are clearly some 16X8 rims that just don't work with the S4's.

So if you run a business and don't want to hand hold every single customer, tell them what you know works 99% of the time.

There's value in leveraging common wisdom and the information that vendors give but nothing beats first hand experience. Particularly if you're looking to do something different than everyone else.

 

We should stick to the facts in this thread.

Like I said in my earlier post in this thread, I have S4 calipers on my early offset car (85.5/86) and 7" 951 phone dials do fit over them. I have witnesses that have seen it in person.

Here is a shot of a 7" 951 phonedial over S4 calipers on my car.

 

Some 16" stock wheels DO fit over BR. However the question here is whether the 7" PDs will fit over S4 Calipers on a late car and the answer is NO. As Jeremy has shown they will on the early cars, however.
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Matt H - Do you know which specific 16" stock wheels will fit over BR's?

You're right, the original question was whether 7"PDs would fit over S4's and I think we've conclusively answered that question but I'd hate to start another thread just for my own minor question.

 

BRs "fit" under original 8" Mg phone dials if the calipers are slightly "peeled off".

 

I stand corrected. I had never tested the 7" Phone Dials over S4's, and just relied on someone else's advice, assuming they had tried it. I'm surprised that it can be done without a spacer, but facts are facts. I broke one of my own cardinal rules: believe none of what you hear, and 50% of what you see. I may now get some 7" Phone Dials, and have two sets of wheels. Good to know.

 

One further thought to tifosiman: are you using S4 rotors? I know someone using S4 calipers with 7" Fuchs wheels on an early offset car, but with the original rotors instead of S4 rotors, and they fit as well. The S4 rotors are thicker than the early ones. Could that be the difference? With 8" Phone Dials on my S4's (calipers and rotors), I have about 1/16" clearance between the wheel and the caliper.

 

I can't use S4 rotors on an early offset 944. They won't work. I have some custom 2 piece slotted units from Coleman. They are the same thickness and diameter as the S4 units, but use the 951 hub.

 

[QUOTE]Originally posted by tifosiman
[B]We should stick to the facts in this thread.

Like I said in my earlier post in this thread, I have S4 calipers on my early offset car (85.5/86) and 7" 951 phone dials do fit over them. I have witnesses that have seen it in person.

Here is a shot of a 7" 951 phonedial over S4 calipers on my car.



Well, how do we know those are really 17s? Maybe if there was a ruler beside it...

 

I have 87/88 spindles and hubs, and I guess that's why I can mount the S4 rotors directly. I switched from the early spindles because the later ones are stronger. Given how little clearance I have with the 8" Phone Dials, and that the 7's and 8's both have the 23 mm offset, it's unlikely 7's would fit my car. However, if I find one, I'll try it and report back.