Difference between M & S calipers

[rolls 912]

Hi

Quick question for those in the know.....

Does the S calipers make a big difference when compared to S calipers?

I have a rebuilt M set but wondering whether I should upgrade (for my 912)

TIA

R

[moneymanager]

What are you doing with the car? An S caliper won't stop the car one foot sooner, but it will dissipate heat better if you are racing. Unless you're racing, save your money.

[4sd911]

The mounting holes on the M and S/A calipers are different, to change from M to S you need different strut housing. The S calipers are aluminum the A are steel as the M are steel to. S and A use the same strut, M a different one. What 912? E? the 65 - 69 912 are very light and don't really need more braking, the E's may benefit with more brake pad.

[rolls 912]

thanks for the info.

It will be in my fully restored '68 912 running a 3.2 as a daily driver. I'm just a little concerned with the extra power and weight. I have installed M calipers with zimms vented rotors....

[4sd911]

My '74 911 had M calipers, I also have a '66 912 with M calipers and solid rotors, the 912 stops better, I did upgrade the 911 to A calipers, the M calipers didn't feel like they would stop the car. The 3.2 motor might be a bit much for the M's. Once you get it together you can test it.

[304065]

Uhh, a 3,2 in a SWB 912 requires at least S calipers, probably A calipers, and you wouldn't be out of place to put a 84-89 Carrera front end on and get some vented caliper and disc adapters for the rear.

[moneymanager]

Ah, you have a 3.2. Why didn't you say so? Yes I would say an upgrade would be a good idea if you plan to do any spirited driving. But I would use the later, wider, A caliper which arrived in 84 for the Carrera. It is a bit heavier (though the factory figured out a long time ago that tire weight variations were bigger than that between an S and an A caliper.) But it allows you to use the later 24mm rotor, which virtually eliminates (or did for me) the brake pad material transfer issues which afflict the narrower rotors. Of course you'll have to sell the zimms vented ones... The A and the S caliper both require a strut change to get the 3.5" spacing.

[Green 912]

3.2 in a 912 = 911. IMO you need far more than what was issued on a 68 912 as far as susp and brakes are concerned if you use the 3.2 at all.

[rolls 912]

Yes, getting the impression that I might be a little under engineered at the front end! I'm also running restored pizza cutters which may cause further issues....

[jmiemiec]

I use M's in a '68 912 with a 2.7s. Rear brakes are unchanged (susp is though) Works great with good balance. Very light car, quick too..