Brembo Calipiers to fit

[victatwin]

Hi all from Australia, quick question for the experts, I want to replace the rear brake calipiers on my 1969 911 , at the moment it has a 1985 3.2 and 915 gearbox with LSD, I believe it also has the standard 1985 rear calipers and rotors (ventilated) fitted as this was a complete conversion done 15 years ago, (get to the point) these are the ATE steel calipiers, the rotor is approx 11 inches in diameter, I`m looking at purchasing a set of Porsche brembo`s from a 1986 944 Turbo, piston size 30mm and 28 mm, part numbers 951 352 421 00 (LHS) and 951 352 422 00 (RHS) the seller could not help me with any info and I`ve tried looking and cross referencing brake pads and rotors on this site, just wanting to know if someone else has converted the same calipiers and is there adaptors to be fitted etc,or it just cannot be done.Are there later model (993) etc that can be bolted straight on ?Any help in the right direction is greatly appreciated. Thanks from the Land of Oz
Brett L

[unclebilly]

Search the forum. I think bill verburg is the resident expert. I am running turbo brakes all around on my race car (gt2 class).

Unless you are racing your car, the Carrera stuff (or even 74-83) stock brakes should be fine for the street. I ran these at the track for years before upgrading to the 930 brakes. The trick to making these work is running good brake fluid (brembo LCF600, motorcycle fluid like DOT 6.1, or endless) to deal with higher temps, and performance pads such as pagid, hawk, or equivalent.

I would spend your money upgrading the fluid and pads of what you have before building a custom setup if this is just a street car.

[unclebilly]

Search the forum. I think bill verburg is the resident expert. I am running turbo brakes all around on my race car (gt2 class).

Unless you are racing your car, the Carrera stuff (or even 74-83) stock brakes should be fine for the street. I ran these at the track for years before upgrading to the 930 brakes. The trick to making these work is running good brake fluid (brembo LCF600, motorcycle fluid like DOT 6.1, or endless) to deal with higher temps, and performance pads such as pagid, hawk, or equivalent.

I would spend your money upgrading the fluid and pads of what you have before building a custom setup if this is just a street car.

[klarsfeld]

I think you can use these calipers, I have a 73 that was running 930 turbo calipers and rotors (and rear banana arms) and swapped this setup for 928GTS calipers which I think are the same as 951 units you are looking at. You will probably require adapter plates (my mechanic had mine custom made by one of his mates). Unfortunately I'm working at a remote location until mid Feb so I can't send you any pics until I get home. I'm sure someone else will chip in with pics and further info.

[victatwin]

Many Thanks for all replies so far, I will continue to search the forum , just to update brake work done.
All rotors machined, new calipier kits all round ,new softer brake pads,(our host supplied), new stainless braided lines all round (again from our host) , Dot 4 high grade brake fluid used, Up front I have the aluminium S calipiers of which would cost nearly $4500.00 from our host to replace,so I`m keeping them on , also a 9 inch remote booster fitted to front brake line only, yet back brakes never get hot, very hard to lock brakes up, I have a 2000 Toyota Camry with brakes that are at least 30 percent better (how can this be) Am I expecting too much? All work professionally done yet I must leave considerable distance for car in front in case they lock up ,I need the room to stop. Front brakes are doing most of the work, no air in system, been bled half a dozen times to make sure. This is why I`ve decided to go to Brembo twin piston calipier, they are for sale in the US so that`s why the question of fittment to my 911, this car is imported from the USA and I`ve kept it LHD, 1969 Targa with steel wide body fitted and all 1985 running gear,2004 Carerra 18 inch wheels, I imported it from LA in 2010, again many thanks for everyone`s valued time and info, no Porsche dealers or machanics where I live. Brett L in Cairns Australia

[victatwin]

Sorry ,forgot to add, new 19 mm brake master cylinder also fitted to car, basically everything replaced or reconditioned, rear wheels are 285 x35 x 18`s so maybe alot of rubber to pull up.
Regards Brett in Oz

[unclebilly]

There is something wrong with your setup if you can't stop the car. Are your calipers installed upside down ( on the wrong side of the car )? This would put the bleed screws at the bottom, not the top and prevent you from being able to bleed them.

What brake fluid are you running? Ate superblue is NOT performance fluid. Ford HD fluid is better than many 'performance' brake fluids but you need to change it regularly because the wet bp is low.

Adding more mismatched components to the system won't fix anything. Figure out what's wrong with your system, it has the potential to work fine.

[unclebilly]

What is this 9" remote booster?

What pads are you running? Did they get oil in them? Are they installed backwards ( pad on caliper )? Something doesn't add up.

I was running 255 race rubber on the track and 285s on the street and my brakes worked fine.

You can buy adapters for the 944 calipers but the problem is deeper.

[victatwin]

Hi Unclebilly, thanks for your quick reply, yes all brake pads are fitted right way round (bought softer pads from Wayne`s recommendation here ) and no calipiers are upside down or back to front,(all bleeders are at the top) this system is standard except for the braided lines to replace the old rubber ones fitted at each calipier, I`ve added the 9 inch brake booster, explanation is a power assist booster that is fitted under the hood in the same place as an original Porsche brake booster (it looks the same as original, google VH40 brake booster),the difference in the short is that your main master cylinder mounted under the drivers side floor on the 69 stays there and the front brake line in that master cylinder runs up and into the remote booster and then comes back out and down to the front brake line union that then divides to each front caliper, I now have a much softer pedal and braking was lifted probably 40 percent in front, there is no air in system, if you jack up car and apply brakes you cannot move rear wheels, but you can see that the pads and machined rotors are not bedding in much at all unlike the front brakes, this is why I`m looking at going to twin piston setup, I will on your recommendation try and purchase a higer grade brake fluid before committing to anything else.
Thanks for your patience and ifo again Brett L

[rsscotty]

Rothsport Racing has developed a rear brake package consisting of rear hat and rotor, 964 caliper and adapter to fit your car. You can email Jeff .. rothsport@frontier.com

He can give you details and probably supply pictures of the package.

[jeff eelkema]

Does the booster operate on both front and rear circuits? My recollection of VH40 boosters on old Holdens was that they worked with single stage master cylinders. When you used a later style tandem master cylinder you needed 2 boosters.

I would ditch the booster and go back to stock plumbing. A booster will NOT improve braking performance. It simply reduces pedal effort but his also reduces pedal feel, one of great attributes of the early cars is the lack of power assistance and real feel!

If you upgrade the calipers you need to keep a balance between front and rear and also between master cylinder bore size. Bigger/more caliper pistons will need bigger master cylinder bore to compensate for greater fluid volume or you will get a long pedal.

You can can me during business hours on 1800 623 456 if you want to discuss. I work for the QLD motoring club and am building a 69E.

cheers

[victatwin]

rsscotty,Thanks for your imput and website of which I will be having a look tomorrow, Jeff , thanks for your number as it will be easier to converse then try to explain everything on the forum, I have to say that the VH40 remote booster has been the best attribution so far in the whole revamp of my braking system, by decreasing foot pressure making pedal travel easier and longer it has increased my braking power at least 40 percent , I know people might want to debate this but it has definetly transferred pedal pressure(very hard into much easier with pedal travelling further) into caliper pressure, I have a brand new VH44 for the rear circult of which I`m not sure wether to fit, brake experts (????) up here want to fit this . If I could find another non boosted Porsche 911 up here to get an idea of how they should work this would be great or someone who knows 911`s and take it for a run and then give me feedback, but to no avail,,I believe mine is the only 69 911 for 100`s klm around ,Again everything is standard bar the booster and all recond work that can be done has been done ,believe me , I would love to just have a good functioning system.I will call soon Jeff even if to see how your project is going , I have some spares as well, At this point I need to take on everyone`s advice and I will keep people posted as to the solution to this issue.
Regards Brett in Cairns Australia.

[TR]

Mate, get rid of the booster and run the standard brake setup. The pedal feel will improve as the new pads wear in and everything beds.

You may also find that the braided brake lines are not legal if they do not comply with the Australian standard.

I'm running the bog stock standard 69 rear caliper with vented discs on the back and aluminium S type calipers on the front. I have had the fronts fully reconditioned with stainless pistons and they work great.

Check to make sure the rears are not seized.

Don't bother to compare Camry brakes with your forty year old Porsche brakes.

we want photos of the car too

Good luck

[Flieger]

Something is wrong with your brakes if you cannot lock them up. I have stock S fronts and M rears and can lock up my Advan A048s (R compounds). Keep in mind that the harder you brake the more weight transfers forward and so the fronts do most of the work. That said, the rears on a 911 do much more work than the rears on a car with a forward static weight bias.

If you can lock your tires, then your brakes are stong enough. You need better tires if you want to stop shorter.

Bigger brakes are a detriment unless you are racing nad experiencing fade and have already tried all the cooling you can get. Otherwise they are just more unsprung weight (and rotating weight) so the car's handling is degraded as is acceleration and deceleration (a little bit).

The unboosted brakes are one of the good things about early 911s. The feel is very direct and more like a race car. I never feel like I am running out of leg strength, though. The tires lock way earlier than that.

[victatwin]

Here are a few photo`s of the 69 Targa, pretty well molested, but it was what I liked and it had Nil rust (big selling point),good enough to import from the US of A.








I hope this encourages others to keep their project going, and yes I`ve been asked if I would convert back to original but just too expensive and not alot of time. Regards Brett in Cairns Australia LHD is better .

[Bill Verburg]

There are a bunch of issues that are associated w/ your brake setup.

If it were my car i'd find some stock '69-83 M rear calipers to go w/ your S fronts. you will want to use stock '69-83 290x20mm rotors w/ them('84 Carrera 3.2 rears are the same diameter but 24mm thick). The first step up from S/M is A/M then wide 3.2C A/M, the wide 3.2 A/wide 3.2M has a bit more rear bias than is usually desirable.


first issue w/ trying to use S front w/ 951 rear is fitment. These can be fitted w/ larger 309x28mm 930 rotors but the 290mm rotors will want the caliper closer to the axle and the mounting ears don't have room to pull them in that far, You may be able to machine off the ears and convert the caliper to radial mounts but that is a lot of work for little reward.

next issue w/ S front and 951 rear you have a lot more rear bias than most people will be comfortable w/

next issue w/ S front and 951 rear the master/slave ratio is too low for comfortable operation by most people(most people would not be able to lock these up either). W/ A or S front and M rear the master/slave ratio is 41.3 meaning that leg effort is magnified 41.3x, w/ S front and 951 rear the master/slave ratio is only 28.138. The lowest I've ever seen on a factory race car is ~30 but w/ boosted brakes. W/ out boost the SC/RS has 33 and late 997GT3 RSR 29 but is driven by Pros at the peak of physical conditioning.

[victatwin]

Hi Bill thanks for the info ,will message you on your personal message board