Tampa 928s

I have an opportunity to swap my 85 brakes front and rear to the newer style S-4 that is now on an 78. First is it worth it and from what I believe you have to change the spindles is there anything else that is needed? I want to make sure this is worth the time and effort for the better braking since I am basically doing this twice.
Thanks

terry gt

rear brakes require s4 calipers / rotors and a washer to space the calipers to fit
front require complete S4 suspension upper/ lower arms /spindles
or a adaptor S brakes to S4 calipers
the early spindles have adapters available not sure about the S spindles

terry gt

braking is much improved
so worth it IMHO
min of 16 inch rims

Tampa 928s

Let me clarify what I am trying to do, both cars have 18' on them now.

The 78 has the S-4 brakes and I believe 996 Rotors.
The 86 has the stock setup.
I want to swap the setup from the 78 to 86 and vs versa.
Can I use an adaptor for the 86 and just install the factory setup on the 78 or need to do the whole suspension change?

Landseer

I've put a complete s4 suspension setup on 84 euro in order to get the oft-heralded big brakes.

Maybe it would matter on a track, but i found it to be a huge effort with no practical value on my car.

You will need to disable antilock, as the s4 spindles require the s4 hubs, which themselves use a different tooth count and computer and harness connectors than pre 86.5 cars

A spacer solution is possible as noted for the mid year cars, but others will need to detail that approach for you, specifically pros/cons, and exactly which brake discs fit and how.

The Forgotten On

Just swap the spindles on the front if it is an early 86 car. Early 86 and back use the same upper and lower control arms so they bolt right on.

Tampa 928s

I am waiting on new brake lines for the swap everything went as planned.

The original rear caliper conversion washers seem like it could use a little better quality.
Does anyone have the washer size needed and what type of washer to use. The washers seem to be a basic Lowes quality and would like to make sure I use the recommended type before I wrap this up.
Thanks

davek9

There is also this option, no need to swap spindles.

http://perfexmfg.com/brakes.php

Tampa 928s

Seems like a good option but I have everything I need. For the rears I would like to make sure I have the correct grade and size of washer that is used for the shim between the caliper and hub mount.

icsamerica

I'm about to swap my rear caliper on a 1986 to S4 brembo. I'd like to use a precision machined washer. Does anyone know the correct thickness required?

Landseer

I think the rears are a straight swap with no washer shimming required of anything.

Fronts, on the other hand, are a major project.

85euro928

I found when putting the S4 brakes on the rear of my 85 that I needed washers. I put the calipers in place and then measured to determine the correct thickness washer needed. As far as the grade of washer just go stainless. For the front calipers Ed's (Perfex) adapters with Cayenne rotors is the way to go. Another bonus was at the time the rotors (320mm IIRC) were less expensive than any of the other big rotors and were readily available.

DR

IIRC 3.5mm thick is what we use.

Cheers,

Dave

icsamerica

Thanks for that and the SS hoses I purchased recently from you arrived quick. The fronts installed easily and look great.