brakes from a 944 turbo? on a 911?

How many here are driving around with brakes from a 944 turbo? I barely remember reading about the 4 piston being put on the fronts of 911's, but is there much difference in stopping power? Is this not what Brembo offers for 911's? Do you have to have a special rotor for the brakes? are the holes identical..or is there some mounting adapter thing?
thanks in advance.............Tlook

Hi Tlook,
The 944 turbo 220 HP brake calipers look exactly like the 964 front calipers, but they have larger pistons.
I put the 964 calipers on my '76 Carrera 3.0, over a 3.2 setup. The mounting holes have to be modified in that the lower mounting hole has to be ovalised. The spacing is 5 mm less on the 3.0-3.2 front strut. Some machine/weld the hole, I just filed it and put a big washer and longer bolt. No problem so far.
The 964 calipers suit the 911 better than the 944 turbo ones, as the piston surface is smaller, creating less bias to the front of the car when used with 3.2 rear calipers. The clearance is minimal, but it hasn't touched my 7X15 and 7X16 front Fuchs. 7X15 phone dial will work too, but not 6X15 phone dial. you may want to find 1992 vintage calipers as they have smaller fins/no fins on them, giving even more clearance.
My $0.02, GeorgeK

The 944T calipers are the same as the C4 and 993 calipers they all have 44/36 mm frt pistons and 34/30 rear pistons. The 944TS used the MO30 calipers in the front these are also called Big Reds, they also have 44/36 mm pistons. The primary purpose of bigger brakes is to increase the thermal capability of the brake system. To that end bigger rotors are required. The 3.2 l Carrera rotors are a small step in that direction. IMO a better one is to use 304x32 mm f and 299x28 mm r rotors from a 78-79 930. The rear is no problem the rotors are a direct bolt on, after you ditch your backing plates, the calipers will need the mounting holes slightly repositioned. In the front you can use factory floating rotors or get after market non-floating rotors, you also need to machine the caliper to accept adaptors for your struts. Here are some pics of this setup on my 76 Carrera 3. 944T/C4/993 calipers, 930 rotors.

Bill, I beg to differ.
The 220HP 944 turbo has 38/36 mm front pistons, then 40/36 mm pistons from end'87 to '88. How do I know? I have one of each in my hands right now. The 964 pistons are somewhat smaller. Hydraulically, the larger pistons provide more clamping force, and more heat transfer.
Regards, GeorgeK

I stand corrected. My notes from the early 944 series sre spotty at best. There was also an odd piston setup on the 92-93 C2 40/36 and 30/28. I wonder if there might also be a difference between euro and North American. Can you post the main physical dimensions? lxw and possibly some pics? I am trying to collate all of the information which I can find on this subject.

Bill,
I'll measure them precisely and I'll post the results here or send them to you.
Regards, George

Oops

[This message has been edited by GeorgeK (edited 02-05-2001).]

George, I did a little more digging and found that there were actually 3 different calipers used on the front of the 944T, not counting the MO30. they are
944T '86 L951.351.421.00 36/38mm
RT951.351.422.00

944T 87-89 L951.351.421.01 36/40mm
R951.351.422.01

944TS 88 L951.351.093.00 36/44mm
MO30 R951.351.094.00

944T 89 L928.351.421.03 36/44mm
R928.351.422.03
So we are both right. It would be interesting to know if you needed to change your mc with the smaller cylinders. I had to change to the 23mm MB truck unit with my 36/44. As I said(I think) when I did this I wanted to keep the option of using the MO30/BigReds without rejuggling the balance, as it turned out it was not necessary to change. The only thing I would do differently is to try to get oem rotors rather than the Colemans.

Guys, here's a couple of sites you might find helpful... http://www.vehiclecraft.com/Brakes/vciweb4.htm http://www.rennsportsystems.com/~porsche/1-sf.html

------------------
Clay McGuill '66 912, '97 Jeep Cherokee www.geocities.com/the912guy

Bill,
You're faster than I am.
I think that the last 2 on your list are the 928 S4 type, i.e. they have a different fastening, radial instead of perpendicular to the disk, making them less straightforward to attach to older 911s.
I kept the std 19 mm master cylinder on my setup. No problem. The travel is alittle longer, but you forget about it in 100 miles.
I don't intend to go bigger as I haven't seen the end of this setup on my 2300 Lbs car in the mountain passes, and I want to keep all the Fuchs I have, 15 and 16.
GeorgeK

George, No, they are all listed as 944T part #'s, they may also have been used on the 928. They are radial mount now and are adapted to the 911/930 struts with radial to transverse adaptors. Don't think they originaly came that way. The original mounts were machined off to adapt them to the 911/930 strut. You didn't need to do this because you used the Carrera 282x24 mm rotor, I used the 304x32 which required the caliper to be moved radially 12 mm more. In the back with the stock 930 299x28 mm rotor the mounts for the brembo calipers just needed to be plugged and redrilled slightly closer together.

Ok...From everything said here, I'm going to try a few things. Tell me what you think, and feel free to correct/Slam anything I'm misunderstanding.
87 944T brakes on my SC suspension w/23 mm MC, and possible bias valve-special caliper adapters for the front, and machining for the rear accompanied by carrera rotors, and early turbo rotors up front.
928 GTS big reds--buy them cheap--put em back for the right rims needed.
I have no leads on the Brakes George is speaking of, nor has he told me What kind of Cash is involved...tell me if your reading this.
Everything else is in the works as you read.

Tlook,
The biggest advantage of bigger brakes is the increased thermal capacity of the bigger rotors. An SC uses 282x20 front rotors, a 3.2 carrera uses 282x24, a 930 uses 304x32, a 3.6 turbo uses 322x32. So first decide what rotor you want/need. I used the 304x32 for a 2400lb Carrera with a 3.6 they work great. George K used 282x24 in his 2400lb Carrera. The 304x32 is a 2 piece unit using a flat hat to bolt to your stock hub. If you want to use the 282x24 rotor you can probably save a lot of time and $ by just buying one of the Boxster monobloc conversions which are set up for the 282x24 rotors, I know Performance Products has them, Pelican also has them (http://www.pelicanparts.com/catalog/shopcart/MISC/POR_MISC_brembo_main.htm)I think there may be a mistake on their page though 12.7" sounds way to big for the rotor, 11.7" is more like it. I would make sure to do both ends of the car at the same time. The 304 or 322x32 has nuch more thermal capacity but it is also much heavier and much more expensive, and requires bigger rims, they are really only needed on heavier, faster cars. In addition the bigger rotors will require machining the calipers to change them from transverse mount to radial mount. You can use the 944T or 964 calipers or MO30(bigred), again I used 36/44 pistons front which balances nicely with the 30/34 rear. In the back the rotors /calipers need to balance the front setup. I used the 299x28 mm 1 piece 930 rotor, it is a direct bolt on and lets you use your parking brake, the calipers only need a minor repoitioning of the transverse mounting holes to work.

Hey guys,
I've been thinking about upgrading my brakes for a while now, just waiting to come across a set for the right price. I was looking at the 944 turbo brakes and am considering those, but does anyone know if it is possible to mount C2 Rear 4 pistons on the front of my car? I can pretty much machine any adapter plate as far as bolt spacing.

______________

Dante Oliverio
86 Cab

Tlook,
The 23 mm master cylinder will give you a hard pedal if you don't have assisted brakes.
The 964 calipers I put in the front cost me around 150$ the pair. I got them in England.
The rear calipers I bought as an exchange on my Carrera 3.0 for about 120$. The disks I bought at a part supplier. They are Factory OEM.
Be CAREFUL with mixing the calipers/disks. You could very easily screw up the balance and end in the ditch. Same goes for the disks and pads. The calipers should match the disk thickness.
GeorgeK