964 vs 944T brakes

[jld]

I purchased a set of calipers off ebay that were supposed to be off an 86 944 turbo as an adaptable upgrade for my 76 911. Doug at vehicle craft [a good guy buy the way] says the 944 fnt caliper pistons should measure 42/36mm. The calipers I received are F-38/36 and R-30/28. I have been told that what I have may have come off a 964 as they have the same body but different piston sizes. Does anybody have any info on this?? I am trying to figure out this whole mess and come up with a decent affordable upgrade for serious DE driveing!
Thanks..jack

[Bill Verburg]

It was discussed here quite recently

Pictures always help

36/39 & 36/40 are the small body axial mounts used on 964 and 944t

the 36/38 was used through '86

after that 36/40 was used except for the TS which used the mid/large size S4 caliper w/ 36/44

[KTL]

In addition to what Bill said, you'll want to consider if you're willing to spend the extra money when it comes time to "rebuild" those calipers. Reason I say that is because the calipers you have are the 36/38 pistons with the old style scraper dust seal. The rebuild kits are a little more than twice the cost of the later style 36/40 pistoned calipers which use rubber dust boots.

To rebuild one 36/38 caliper it'll cost you ~ $216 (4 piston rebuild kits @ $47.50 ea. x 2 for the 38 and $60.50 ea. x 2 for the 36). To rebuild a rubber booted 36/40 costs ~ $90 (4 piston rebuild kits @ $24.50 ea. x 2 for the 40 and $20.75 ea. x 2 for the 36).

I have the exact same 36/38 front and 28/30 rear VCI setup on my car. It works great on the track at DE events. Before me, it was run on Chris Streit's NASA GTS4 1970 911S 3.3L race car. Worked good for him too, but he decided he needed some more thermal mass. So I swapped him my "993" brakes and he gave me the 951 VCI setup.

[jld]

GRRREAT....more decisions to make!! Bill thank you for the link, i'll check it out tonight after work! Kevin.. I have heard that you can open up the inner clearance on the bodies to fit 930 rotors on the rear for the ,all important, thermal mass issue . otherwise the suggested rotors { VCI} are stock 944 turbo fronts and stock 911 rears[which do nothing for thermal mass]. Have you seen or heard of this being done??
THANKS ALL for any ideas...jack

[KTL]

Jack,

You can probably resell the calipers for what you paid for them. Wait patiently for a set of Brembos with the rubber boots to pop up in the classifieds or eBay. Good deals are there to be had all the time.

I scored my like new 993 calipers and rotors off ebay for $750 a few years ago. Traded the rotors for some used track tires and my math tells me I netted the calipers for ~$500 I've picked up sets of front and rear rubber booted 964/968 calipers here on the classifieds and off eBay for $200 or less per pair.

You can indeed open up the rear throat and crown of the caliper to fit the spendy 930 rotor. That rotor is a bit of overkill but it does fit better than the overhang you get from a stock Carrera rotor. The thermal mass is not as big of an issue at the rear. But it's nice to have. My one problem with the 930 rotor is that it's a little expensive and perforated so you'll get some cracking between the holes. Although there's probably not a better priced, better quality perforated rotor you could choose for the rear application besides this one. Nonetheless i'm cheap and choose to live on the edge and go with the Carrera rotor and a tiny bit of pad overhang- approx. 1/4 in.

And by the way you don't have to have VCI adapt the rear caliper. You can fill and re-drill the holes yourself or have a machine shop do it. Even a hack kludge like me can do it!!

930 Rear Rotor Under 993 Caliper