Porsche 944 Turbo brakes on a 911?

Hotwatermusic · 10-15-2009, 06:11 PM

Apparently I have the brake calipers from a 944T in my 1974 911. Is this a popular "upgrade" or did my PO not want to pony up for real 911 parts for one reason or another? The front rotors are from a Carrera, with the 944 calipers. The brakes work, but damn you gotta leave a lot of stopping distance between you and whatever you don't want to hit. If 944 brakes on a 911 are an upgrade, what's the_upgrade_over that? Cause these aren't cutting it...

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by Hotwatermusic

Apparently I have the brake calipers from a 944T in my 1974 911. Is this a popular "upgrade" or did my PO not want to pony up for real 911 parts for one reason or another? The front rotors are from a Carrera, with the 944 calipers. The brakes work, but damn you gotta leave a lot of stopping distance between you and whatever you don't want to hit. If 944 brakes on a 911 are an upgrade, what's the_upgrade_over that? Cause these aren't cutting it...

Sound like bastardized setup to me. Another backyard engineer strikes again

you apparently have at least 2 separate but related issues
issue 1- inappropriate calipers
issue 2-inappropraite m/c

some extra infromation is needed, I assume that 3.5" struts are being used
are the 944 calipers used in back also?
I assume that your complaint is related to extremely high pedal pressure?

djpateman · 10-16-2009, 05:40 AM

In addition to what Bill says, try and check the piston sizes in the 944 calipers. The 944 turbo front and rear calipers are very similar, but piston sizes are way different; 38 & 36 front vs 30 & 28 rear. If rear calipers were used on the front of your car there would be very poor braking performance. It is not uncommon to be fooled by the size of the caliper.

Dantilla · 10-16-2009, 08:00 AM

I wish my 911 had the brakes of my old 944 Turbo.

I've been using an old 15" Cookie Cutter for my spare. I just acquired a 7x16 Fuchs so that when I upgrade the brakes, I have a spare that will fit.

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by Dantilla

I wish my 911 had the brakes of my old 944 Turbo.

...

The 944 system which consists of calipers, rotors and m/c is a fine setup when used in it's entirety(w/ a minor m/c substitution due to the physiacl difference between 944 & 911)), taking a piec here and a piece there and slapping it somewhere else is not a good way to set up a car.

Formerly Steve Wilkinson · 10-16-2009, 11:15 AM

Steve Weiner does it right with 944 Turbo brakes on 911s. Contact him at porsche@rennsportsystems.com if you still have questions.

Dantilla · 10-16-2009, 12:55 PM

Quote:

Originally Posted by Bill Verburg

The 944 system which consists of calipers, rotors and m/c is a fine setup when used in it's entirety(w/ a minor m/c substitution due to the physiacl difference between 944 & 911)), taking a piec here and a piece there and slapping it somewhere else is not a good way to set up a car.

Precisely why I haven't touched the brakes yet!

I don't believe in swapping a part or two at a time. When I decide the best brake SYSTEM for my car, I will do it all at once, and be done with it.

Steve Weiner is just down I-5 from me. I'll probably be talking to him when I'm ready.

Steve@Rennsport · 10-16-2009, 02:50 PM

Quote:

Originally Posted by Formerly Steve Wilkinson

Steve Weiner does it right with 944 Turbo brakes on 911s. Contact him at porsche@rennsportsystems.com if you still have questions.

Those are actually 930 ones,.......

Formerly Steve Wilkinson · 10-16-2009, 03:20 PM

Who'd a thunk it. All along I thought mine were 944s. Now my SC is worth $85,000, not just $80,000, I guess...

Steve@Rennsport · 10-16-2009, 04:22 PM

Quote:

Originally Posted by Formerly Steve Wilkinson

Who'd a thunk it. All along I thought mine were 944s. Now my SC is worth $85,000, not just $80,000, I guess...

Its not simply gold-plated, anymore,........

Hotwatermusic · 10-16-2009, 05:28 PM

Quote:

Originally Posted by Bill Verburg

The 944 system which consists of calipers, rotors and m/c is a fine setup when used in it's entirety(w/ a minor m/c substitution due to the physiacl difference between 944 & 911)), taking a piec here and a piece there and slapping it somewhere else is not a good way to set up a car.

Here's what I've found: I have a 1974 911 (non-power brakes), but with Carrera front struts and rotors, and red 944 Turbo 4 piston calipers on the front. Is this the normal way the "upgrade" is done? The back brakes weren't touched. I'm just annoyed cause to do front brake work I have 3(!) different cars I have to reference: 74 911, god-knows-what-year Carrera, and god-know-what-year 944.

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by Hotwatermusic

Here's what I've found: I have a 1974 911 (non-power brakes), but with Carrera front struts and rotors, and red 944 Turbo 4 piston calipers on the front. Is this the normal way the "upgrade" is done? The back brakes weren't touched. I'm just annoyed cause to do front brake work I have 3(!) different cars I have to reference: 74 911, god-knows-what-year Carrera, and god-know-what-year 944.

That's a kludge

here's what you want to do
retain the struts, front rotors(I'm assuming that they are the usual 24mm 3.2 Carrera rotors used on these sort of things) and rears as is, just be sure that they are nominal. Get some nice soft street pads

Get a set of '84 -89 911 front calipers, bolt them on

Check the m/c to be sure that it is a 19.05mm, not a 23.8mm. The m/c bore is embossed on the side of the casting, usually you can read it w/ a flash light from below.

If you can' read it the 23.8 is longer and will come right up to the cross member, if it's a steel cross member it's almost impossible to fit a 23.8

here's what a 23.8 looks like installed

and here's a side by side, 23.8 on top

axvel · 10-17-2009, 07:47 PM

i have all 4 944t calipers and they are great!!! on a 1977

Hotwatermusic · 10-17-2009, 10:07 PM

Quote:

Originally Posted by axvel

i have all 4 944t calipers and they are great!!! on a 1977

What pads and brake fluid are you using? Are you using the original size rotors? Did you specifically want those brakes or were they on the car when you bought it? Are the 944T brake calipers the same for every year the 944 was made? See, my problem is if I want to get new pads I don't know what year/or option package these brakes are. I know that's a lot of questions, but if you are running the same setup, I'd love to know more...

axvel · 10-17-2009, 11:31 PM

Quote:

Originally Posted by Hotwatermusic

What pads and brake fluid are you using? Are you using the original size rotors? Did you specifically want those brakes or were they on the car when you bought it? Are the 944T brake calipers the same for every year the 944 was made? See, my problem is if I want to get new pads I don't know what year/or option package these brakes are. I know that's a lot of questions, but if you are running the same setup, I'd love to know more...

I'm using blue fluid from pelican, i have the brakes from the 88 944t, when i recently changed the pads, i requested the 944t 1988 year, very simple.

I got them because i wanted larger less expensive caliper look, similar to the 964.

The rotors i used very orginal ones for 1977 911

if you have anymore questions let me know

johnsjmc · 10-18-2009, 06:25 AM

On my 1980SC I have 944T fronts with 28 mm rotors and use 3.2 Carrera 24mm rears and their matching calipers without a proportioning valve. Decent balance (slightly front biased) .I have a 23 mm master but haven,t gotten around to installing it yet. Street driven with 3.6. Seldom think I need this much brake,but like the looks anyway.

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by axvel

I'm using blue fluid from pelican, i have the brakes from the 88 944t, when i recently changed the pads, i requested the 944t 1988 year, very simple.

I got them because i wanted larger less expensive caliper look, similar to the 964.

The rotors i used very orginal ones for 1977 911

if you have anymore questions let me know

I know that you don't want to hear this but that is another kludge

964/944 fronts want a 28mm rotor, the usual 24mm rotor used is bad enough but a stock 20mm is downright dangerous.

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by johnsjmc

On my 1980SC I have 944T fronts with 28 mm rotors and use 3.2 Carrera 24mm rears and their matching calipers without a proportioning valve. Decent balance (slightly front biased) .I have a 23 mm master but haven,t gotten around to installing it yet. Street driven with 3.6. Seldom think I need this much brake,but like the looks anyway.

This one is a decent setup

johnsjmc · 08:17 AM

I agree that 20 mm fronts are DANGEROUS. Part worn pads could allow pistons to fall out of calipers.
The other problem the original poster must be experiencing is HUGE front bias with the original small piston rears.. No wonder his stopping distances seem poor.
Return to stock or cheap upgrade to 3.2 Carrera fronts (calipers AND rotors) would be my opinion.Then add red plastic caliper covers for the 4 piston bling look

axvel · 10-19-2009, 01:24 PM

Bill, i'm very interested in your opinion, could you further explain please?

I currently have the zimmerman rotors for 1976-85 that i ordered from our host, also the pads are new and they brake like crazy. Instant stop. What could possibly go wrong?

If you have a recommendation for the good rotors to use please let me know. Our host doesn't list the width of the rotor.

Thanks

Quote:

Originally Posted by Bill Verburg

I know that you don't want to hear this but that is another kludge

964/944 fronts want a 28mm rotor, the usual 24mm rotor used is bad enough but a stock 20mm is downright dangerous.