Replace SC brakes with Carrera Brakes

[ady930]

I have a 69 912 that has been extensively being upgraded to a 3.0 liter turbo. It has 911 SC brakes. Can i put Carrera discs and calipers on without to much of a modification.

[MattAlpha]

That is the current set-up of my 911 from the SC to the Carrera brakes.

If you currently have M and A calipers and rotors, then its a simple bolt on replacement with the wide A and wide M calipers and rotors. If you do not currently have the vacuum assist module with the SC/Carrera master cylinder then you will need to purchase that as well and plum a vacuum line for the vacuum assist module.

If you do have the proper M/C and vacuum assist module than this will be a vary straight forward upgrade. The only thing that is difficult is installing the brake ware sensor system into the dash and running the lines to each caliper. This will also include the mount hardware under the car for the wear sensors to the umbilicals. My brake wear system is not operating because I do not have the umbilicals that go from the wear sensors (which I have also removed sense they were useless) to the dash mounted unit.

This is no reason not to do the upgrade, it just means that you will have to take a look at your pads every so often, which you probably already do anyway.

I say go for it,
Matt

[Bill Verburg]

Originally posted by ady930
I have a 69 912 that has been extensively being upgraded to a 3.0 liter turbo. It has 911 SC brakes. Can i put Carrera discs and calipers on without to much of a modification.

Put the Carrera calipers and rotors on the front only. There is no need for them in the back, and there wil be no change in bias that would require a p/v. Stock m/c will be fine as there is also no change in the hydraulic requirements of the calipers.

[MattAlpha]

Bill's method is also much cheaper as well.

[Craig 930 RS]

Recall that the only benefit for your application is thicker front Carrera rotors vs. the 911SC. Same pads.
And if you aren't tracking the car, why bother with the change?

[palle7688]

I do not totally agree with Bill.
Depending on if you are using bigger rear wheels you can actually use some more clamping power at the back and because of that you can use the Carrera calipers at he back as well. The Carrera brakes uses larger pistons in the rear calipers AND a pressure limiting valve to prevent locking the rears wheels. If you are using bigger wheels and has the heavier engine I suggest using Carrera brakes front and rear.

[Drago]

Excellent to hear validation to my plans. I'm installing a set of Carrera brakes on my '69T soon. I was planning on swapping both front and rear brakes but now I'll only do the fronts as I'm not installing larger wheels to get the power from the punny little 2.0L to the ground (yet). The car will eventually see track time on a regular basis.

[Craig 930 RS]

Then make certain you don't install the splash guards for track use - and install a cooling kit for the fronts.

[Eagledriver]

I have Carrera brakes front and rear on my car with no proportioning valve. I wouldn't have done it that way but the car was that way when I bought it. I've raced the car that way for 5 seasons now. While I don't brake quite as deep as some of the others in my race group I don't feel like the balance is too bad. I don't lock up the rears and if I turn slightly when braking I'll lock up a front first due to the unloading of one front wheel.

For street use I'd say this set up is no problem. The best solution would be to install with a PV or a brake bias valve.

-Andy

[rusnak]

There are some new brake pads out that I hear are really good, called BHP. I haven't tried them yet, but personally I'd go that route first, then try cooling second.

The switch to new brakes is like buying a new knife instead of sharpening the old one. I think a logical starting point is to ask, what are you trying to accomplish? More fade resistance, or more initial bite?

If your problem is fade, and not initial bite, then I'd try switching just the front to Carrera brakes before jumping in and changing all 4 at the same time. The reason is that the Carrera had a lot more ft/rr weight bias than the earlier cars.

The principal benefit that I could see offhand would be the (much) thicker rotors. The drawback would be the thicker rotors weigh a lot more too. The reason for thicker rotors I think would be to offer a better heat sink for dissipation of braking energy. You could just bolt on the Brembo rotors for the Big Reds, which I think are a bolt in replacement on the Carrera brakes. The main benefits of the Brembos are that they are made from a higher quality metal than the Zimmermans, and of course they are drilled. The drawback of the Brembo rotors is that you lose some brake pad area unless you switch to bigger calipers (more initial bite), but now we are not talking about Carrera brakes anymore.

So, I'd stick with your SC setup as long as you can, just upgrade the pads and put some cooling scoops on there.

[Craig 930 RS]

He needs appropriate track pads and cooling is a must -- IF he takes it to the track.
As of now, he has not replied to the affirmative.

Not too certain about the rest of your advice, Rus.

[rusnak]

Craig, I'm not the one saying BHP pads are track only, that is your insinuation, although you didn't go out and say so. As far as cooling goes, you're also advising him to add cooling and delete splash guards.

The guy is planning to upgrade his brakes, and he says he might track it later.

I don't know what you're arguing about here....

[Craig 930 RS]

I didn't make an insinuation. I merely said:

1) ady930 did not say he was going to use the car at the track
2) If he is, to use pads that are appropriate.

I prefer to use pads that are absolutely proven to take the extreme punishment the small pad size/relatively small disc mass/large heat saturation will deliver to the fluid and pads.
It is no fun to have these small brakes fail on a car that easily sees 120 mph + on every track day.

BTDT myself on the SC, and have heard too many tales of terror - being in the Porsche brake biz for 4 years.

Cooling for tracked Carrera brakes is absolutely paramount, SC even more so.

ady930, you out there to clarify your intended use?

[rusnak]

OK Craig, I agree with you on the need for proven track pads for track use, I even agree with you on the need for increased cooling. I'd even agree with you if the car was going to be used on the track, if you had said the need for heat dissipation means he should use thicker rotors.

Carrera rotors are quite a bit thicker and heavier than SC rotors. I have an SC and a 3.2 and for some reason the SC stops a lot faster. I think it's because the SC weighs less than the 3.2. In my opinion the SC brakes are plenty strong to stop an early 911. The issue is fade due to heat, which is where the cooling issue comes in. I don't think street use on an early 911 is the right application for Carrera rotors, which come with a significant weight penalty. If it were a track car it might make sense to use 3.2 front calipers and Brembo rotors, but again you'd lose some brake pad surface area. There are companies out there that sell 930 turbo brake conversions that use the Brembo rotors.

[Craig 930 RS]

It just isn't that significant of wieght difference - really, no one will ever be able to tell the difference.

How do you lose pad surface area with the exact same caliper on this Brembo rotor?
Seems to me.....the pad is the same.

And until ady930 responds, this is all bantering conjecture on both our parts.

[rusnak]

True Craig,

We are just bantering here. The drilled rotors have less contact area than stock solid vented ones.

One can argue that the drilled rotors apply more braking efficiency due to gas venting, as in the first tests on the 917 drilled rotors.