Identifying brake calipers

[Tp81]

Hopefully someone is able to help, I was looking for calipers for my e and was able to source a set I believe to be original to my car.

As is usually the case I then found another set for sale which I bought and think might be S type calipers. I have also been told that with my car being 1973 car would have had S front calipers fitted from the factory.

The set pictured below are the ones I managed to source and will need to refurbish, there is an obvious difference in size between what I assume is front and rear. The other set I have are all more or less the same size.

Can someone tell me what type these are?

[Nick Moss]

S calipers are aluminium, yours are steel. What is the hole spacing? Are there any spacers between the caliper halves. What is is disc width space?

[Tp81]

Thanks. I will take some measurements and come back to you.

Looking at the parts detail Porsche have sent me through, the E should have the s type which is obviously the alloy calipers.

Is there a difference in the performance of these or is it weight only?

[Nick Moss]

Looking at the parts detail Porsche have sent me through, the E should have the s type which is obviously the alloy calipers.

For your car? Does it have 3.5" caliper fixings?

[davep]

The easiest way to identify is looking at the fluid inlet. If these are larger than the rear calipers, then there is a good chance that these are type A. Front & rear M calipers take the same pad size. A & S have the same pad area, but S pads are thicker.
Basically, all M, S & A calipers on the front have 48mm pistons. A & S have pads with more area. S calipers are much lighter (unsprung weight) and have greater thickness pads to wear away.

[Slope330]

Tom, i think u ll find u cud specify S callipers from new ........few years back i had a '73 E with full s roll bars and brakes on original spec sheet...............

[fetuhoe]

If these photographs are taken on the same 'scale' the they both have 3" mounting centres.

As Nick says all Aluminium S style Calipers have 3.5" centres on the front brakes.

The E was fitted with the Aluminium Caliper and so the calipers in the photograph are incorrect.

If you have the correct front struts these calipers won't work.

The thickness of pads is becoming a problem and all of the Pagid Race pads are now only available in the 'thin' (15mm), the 19mm having been dropped some time ago.

I think that Ferodo and most other 'performance' pads have the same problem.