944T calipers on my 911

[MotoSook]

Has anyone used -the 19mm, then 23mm M/C? Feedback?

Bill, as you know, I'm on a budget, so I'm thinking the 19mm will be used until I can fit the 23mm M/C into the budget. I know that doesn't make that much sense since it will be a small fraction of my total winter budget cost, but I'm doing other things this winter too, besides the brakes. Geez! I trying not to think of the total cost ...might as well just go buy a built car

[cstreit]

Bill,

Why is it that I am not shocked that you would be able to reference ergonomic data? I stand corrected.

[Bill Verburg]

Has anyone used -the 19mm, then 23mm M/C?

Yes, a 19.05mm is hydraulicaly too small, the result is rear wheel lockup under extreme braking. 20.6 would be the smallest that would function correctly though the feel will be vastly improved w/ 23.8

Additionally the 23.8mm ATE needs to have the late aluminum x member in place

[MotoSook]

Thanks again bill...

Kevin informed me of this thread , which I think is a great read after someone has gone through the above posts.



...Gee, I wonder if a moderator won't make this the "Ultimate 951 (944T) Brake Upgrade Thread"

[Bill Verburg]

Kevins got a better memory than I.

[911-32]

This really has become the ultimate 964/944t brake upgrade thread, but what would make it even better would be if Souk or Chris Streit could post a full set of pictures. It would provide a good "how to" for people considering the upgrade.

I am about to buy a set of 1992 964C2 calipers to use on my 1989 3.2. I am in no hurry to get this done but I want to start accumulating the parts. Any issues with these calipers? I would go with 951 28mm thick discs front and std 3.2 rear as per Souk. I figure from the MC thread above, I can use the std 3.2 boosted MC. I also figure that the proportioning valve would be removed. Any mistakes so far?

Just to pre-empt the obligatory "why do you need to upgrade" comment, well, maybe I don't right now. For this summer my car is a little lighter, a lot stiffer, a little faster and has bigger, stickier rubber than ever before. I can pretty much drive around the soft pedal issues but the short life of brake pads and constant bleeding are getting kind of tiresome. For various reasons, I can't make my car significantly lighter (currently 1260kg with me in it) so I am thinking bigger brakes.

I am hoping someone local (UK) can adapt the calipers. Any UK Pelicanites got any leads? Maybe I just send them to VCI - the USD is cheap vs Sterling right now!

Cheers,
Richard

[palle7688]

I too would like to see how they have done this upgrade.
Pics please!!!
Also I would like to see a 951 rotor on a 911 hub. Is it installed on the outb. (wheeel) side or the inside (normal rotor) side?
The pics I've seen of a 951 rotor it seems like it has 5 big(14 mm) holes for wheel studs. and 4 small (6 mm) for holding it to the hub. If it's installed to the outside I don't see why it's necessery to file on the lower A-arm??
Answers please!

[911-32]

Repeating earlier request to Chris Steit or Souk. Anybody out there?

[MotoSook]

Gang,

I've been busy trying to get my car ready for an April 19th track day, and have not started the brake project yet. You can pretty much put together some info from the above, VCI and Bill V's site, or check back here in a while or at GruppeB. I'll be posting when the work starts.

Sorry guys.

[palle7688]

Souk.
Quote
"Comparing a couple of sites (SW's and VCI, their rotor measurements are not identical..understandable..even stated as "rough" on SW's page)"

VCI I know, what is SW?

You can be sure I'll be waiting for your post.

[MotoSook]

SW=Steve Wiener (sic?, sorry Steve).

I've got about 40 page PDF file that I created for the 951 upgrade. If I ever finish my car, I'll trim the file down and format it for easier reading and comprehension....I'll post it somewhere...

[Bill Verburg]

Here is a pic of a stock 964 front caliper


Here is a pic of a 964 modified for use w/ a 930 rotor


Here is a caliper modified in a manner that I cannot endorse for use w/ Carrera rotors

[cstreit]

Bill,

That picture looks familiar!

Gang, I'll agree with Bill and say that are some issues with putting the larger calipers on the front with the drilled out mounting points. Been there, done that.

I did this modification several years ago to try and solve a heat problem in the front calipers of my racecar. Result? I solved the front heat problem, but only because I moved the problem tot he rear! By putting the larger calipers up front I effectively changed the bias rearward resulting in a somewhat imbalanced system. Plus with this modification you can't upgrade rotors which are the bits that are responsible for the heat capacity of the system.

I ended up using Doug Arnao's setup from VCI. It uses the 944T calipers machined with special adapters. I use a 944T stock disc up front, 299x28mm I believe. THe rear uses a Carerra rear disc (298x24mm).

There is a 4mm spacer that does behind the bearing to move out the front hub assembly. Otherwise your disc will hit the a-arm/ball joint in front. A 1/8" spacer was required in the rear to keep the caliper off the wheel.

I don't have many detailed pictures of the setup, but here is one. You can go to VCI's website for more pictures.


My setup:


From VCI:

[palle7688]

Chris, thanks for posting, gives a better understanding of how you have done yours.
I'm still researching.
Acc. to my wrench it's better/easier to use the '89-'93 C2 298*28(or newer/bigger) rotors which installs to the outside of the hub. This requires the hub to be be milled/turned a little to fit inside the rotor. This is what Beepbeep (and InstantG) is doing.
This way it's not necessery to file the lower A-arm and saves you the spacer behind the inner wheelbearing.
If I could use 996 calipers with C2 rotors the only special manufactored part would be the adapter, now we are getting somewhere!!! :-)
See on attached pic. from Beepbeep, hub in background is done.

[Bill Verburg]

Acc. to my wrench it's better/easier to use the '89-'93 C2 298*28(or newer/bigger) rotors which installs to the outside of the hub. This requires the hub to be be milled/turned a little to fit inside the rotor.

Now that is an interesting idea. Yes that is what Steve and Beep did, but w/ the 322x32mm one piece 993tt rotors. My preference for weight reduction is the 2 piece 993tt w/ a flat aluminum hat.


The 993tt rear can be used if a 911 parking brake is pinned to the rotor in place of the 993 unit


A better choice at the rear is still a 965 caliper on a 930 rotor

[palle7688]

Bill, your prefered front rotor alum. hat, is that homemade or OEM for that rotor? What is the rotor size?

Quote: The 993tt rear can be used if a 911 parking brake is pinned to the rotor in place of the 993 unit

My English is not my native language so please explain?

BTW, nice rug you have under your car:-)

[Glasgow 911SC]

Jeeez this is confusing Major brain ache!

[Bill Verburg]

You are always better off buying from someone that has done it before. My current setup is from Race Technology. They are the North American arm of Brembo. In Europe Movit is the best comparable source.

My rotors are stock 993tt 322x32 front and 322x28 rear. the fronts are the 2 piece versions. The stock hat is removed and replaced by the flat hat w/ the same hardware. The rear rotor needs to have the stock parking brake modified by pinning a 911/930 parking brake inside the stock hub volume. You can see the 5 places were it is bolted in .

Glasgow 911SC, not confusing at all
there are only a limited #of combinations that work
All are outlined here

The hard part is doing it cheaply

[beepbeep]

Ello!

We dunno a squat about brakes...we just used what local race-car wrench uses on his hot cars. It's 965T disc, 993TT caliper, billet caliper adapter and machined hub combo in the front and 930 disc and modded 930 caliper in the back. Mattias did the modification to rear brakes thanx to his extensive machine-park.

For you wanting to know what is involved in mounting 930 calipers in the back, here are some pics (click on them to enlarge):

Take two 930 calipers, cut off the ears and drill new holes:


Make holes counter-sunk so distance-rings fit nice and square w/o flexing (many shops use simple cylindrical distances which I don't like beacuse of skewing motion, so I talked Mattias into doing our own custom counter-sunk ones):






Everything bolts up nice and easy:


Fronts are bolt-on (yeah, we turned the caliper upside-down ):


Top it off with 23mm MC for good measure:



Then install some cooling ducts (no pics)...it should work nice.

Good thing with those Big Reds in front is that pads and discs are cheap, cheaper than 930 parts...bad thing is that they are heavy and aren't floating.

Dunno about fender/wheel clearance issue...we don't have the wheels yet It's just a matter of doing some cut & paste (we have fiberglass fenders)

[Bill Verburg]

Good thing with those Big Reds in front is that pads and discs are cheap, cheaper than 930 parts...bad thing is that they are heavy and aren't floating.

Yeah, thats the primary reason why I switched. but to the lighter 2 peiece versions

The 2 piece 322x32 rotors weigh 18#ea. installed

Goran, do you have the weights of the 1 piece versions?