944 S2 to 944 Turbo S front brake calipers
 

944 S2 to 944 Turbo S front brake calipers:

I believe adapters ("elephant ears") are required
because of mounting differences, but
isn't a new master cylinder also required because of the
larger fluid displacement? Some people have
advised me it is unecessary, but I am concerned the brake pedal
will be softer, i.e., greater travel to offset increased
fluid displacement, if the master cylinder isn't commensurately increased in size.

Also, if the fronts are upgraded, should the brake bias valve be
upgraded to balance the rears out with the front?

Thanks!

Forrest
1989 944S2

I don't know enough about the S2's to comment, so you might want other opinions as well, but, I believe the S2 had the same exact brakes of the 968 and the regular Turbo, so the master cylinder should be okay. You might want to reconsider the S4 calipers though- Big Reds are much cheaper, and easier to find, and also have more rotors available. Of course, if you're running 16" rims, you probably won't be able to clear w/BR's. The biggest advantage b/t BR's and S4's is the size of the rotor- even though S4's can hold a bigger one in the end, all of the BR rotors start at 322mm (12 5/8") whereas the S4's have 12"... Also, the BR's have a tiny bit less piston bore, which should help you w/the pedal travel issue.

If you just want the S4's anyway, call a place like KVR- they seem to be the only ones who will help you w/them...

I also plan to use a 928 bias valve w/my Turbo S (I'm keeping stock calipers, but will eventually go to 13" rotors- hopefully 2-piece- all around when I go to 17" 968 rims)- places like Technodyne sell bias valves and would know what size would be best for you...

You can keep the same Master.
Replace the Bias regulator with a 5/33 bar unit Part # 928.355.305.02 Around $70
Dealer or Paragon Products