964 brake upgrade

[Markh]

have searched and cant much, have been told that 993 TT brakes are a pretty much bolt on upgrade, can any one confirm? , am running 17' cup 2 rims by the way

many thanks

[Slippydiff]

Boxey who post on here will be able to give you all the information you require, but should he not be forthcoming, you'll find all the information you need on the Rennlist 964 forum. Bill Verberg knows everything there is to know about 993/964 brake conversions ! 1

[freedman]

As above Bill Verburg on RL is the man

http://forums.rennlist.com/rennforums/964-forum/36...

There are dozens of threads about options on there

Big Reds, (993t) or Big Blacks, (928S4) With appropriate discs and adaptors for mounting are the most popular upgrades

They will fit no issue with 17in wheels

[Rutlandracing]

Mark

Talk to Brian at Jasmine, he fitted the brakes to my much modified 964, they are stunning, stop amazingly well and absolutely no fade. I'm running, 993 turbo braking system front and rear, Calipers painted red and stove enameled with Porsche logo in white, crossdrilled discs, custom ordered 964RS at the rear, Castrol high temperature braking fluid, EBC Red Pads and stainless steel braided brake hoses. Superb stopping power.

[barchetta_boy]

Assuming you can lock the wheels up with the current setup, what are you hoping to gain?

[boxsey]

Slippydiff said:

Boxey who post on here will be able to give you all the information you require, but should he not be forthcoming, you'll find all the information you need on the Rennlist 964 forum. Bill Verberg knows everything there is to know about 993/964 brake conversions ! 1

Boxsey reporting! I've only upgraded the weedy rear 2 pots to the later 4 pots. My write up, including removing the infamous plate lift, is here:

http://964uk.com/Documents/Brake%20Upgrade.pdf

I agree that Bill has written up on Rennlist everything you need for further brake upgrades.

[Slippydiff]

barchetta_boy said:

Assuming you can lock the wheels up with the current setup, what are you hoping to gain?

Improved heat management and better durability I'd imagine (along with the increased confidence as a result)

[ras62]

Mark, if you are still using the original rear 2 pot calipers then I would suggest leaving the fronts alone for the moment and changing rears first to 993 C2 4 pots. The proportioning valve can also by changed to 55 or 60 Bar, or even removed all together. Its a nice mod and certainly makes a difference.

[boxsey]

ras62 said:

Mark, if you are still using the original rear 2 pot calipers then I would suggest leaving the fronts alone for the moment and changing rears first to 993 C2 4 pots. The proportioning valve can also by changed to 55 or 60 Bar, or even removed all together. Its a nice mod and certainly makes a difference.

Rob, it's not advised to use 993C2 rears with standard 964 fronts because the pistons are too large and promote too much rear bias. The 993C2 rears are the ones that should be used when putting big brakes on the front at the same time. If just changing the two pot rears the calipers that can be used are 964C4, 993C4, 944turbo, 928S4 and of course late 964C2 (very rare second hand). All of these should also get the 55bar p/v as you say.

[Markh]

ras62 said:

Mark, if you are still using the original rear 2 pot calipers then I would suggest leaving the fronts alone for the moment and changing rears first to 993 C2 4 pots. The proportioning valve can also by changed to 55 or 60 Bar, or even removed all together. Its a nice mod and certainly makes a difference.

yes I am, will looking this, thanks

[ras62]

boxsey said:

ras62 said:

Mark, if you are still using the original rear 2 pot calipers then I would suggest leaving the fronts alone for the moment and changing rears first to 993 C2 4 pots. The proportioning valve can also by changed to 55 or 60 Bar, or even removed all together. Its a nice mod and certainly makes a difference.

Rob, it's not advised to use 993C2 rears with standard 964 fronts because the pistons are too large and promote too much rear bias. The 993C2 rears are the ones that should be used when putting big brakes on the front at the same time. If just changing the two pot rears the calipers that can be used are 964C4, 993C4, 944turbo, 928S4 and of course late 964C2 (very rare second hand). All of these should also get the 55bar p/v as you say.

Hi Steve. TBH I am not sure if mine are 993C4 or C2, I assumed C2. The difference being piston size are 28/30 against 34/30. In reality I doubt there is any noticeable difference as the front rear bias is dictated more by the p/v than one of the pistons being slightly bigger. I have kept the 45Bar valve but some use 55, 60 or no valve at all and report good results. Adding an LSD changes the situation again, so I dont think there are any definitive combinations apart from what was originally built by the factory.

[aceparts]

Not sure if they're of use but I'm VERY soon replacing all 4 of my recently refurbished calipers off my 993 turbo if you fancy them? I had them completely rebuilt with new seals, pistons etc a while ago after having them cosmetically refurbished. Unfortunately the cosmetics have not lasted well but mechanically they're perfect.

[Markh]

aceparts said:

Not sure if they're of use but I'm VERY soon replacing all 4 of my recently refurbished calipers off my 993 turbo if you fancy them? I had them completely rebuilt with new seals, pistons etc a while ago after having them cosmetically refurbished. Unfortunately the cosmetics have not lasted well but mechanically they're perfect.

Good to know, as I am mid purchase, can you email me off forum wjth a time frame and cost?

thanks

[Markh]

boxsey said:

Rob, it's not advised to use 993C2 rears with standard 964 fronts because the pistons are too large and promote too much rear bias. The 993C2 rears are the ones that should be used when putting big brakes on the front at the same time. If just changing the two pot rears the calipers that can be used are 964C4, 993C4, 944turbo, 928S4 and of course late 964C2 (very rare second hand). All of these should also get the 55bar p/v as you say.

If I use the two pot rears, is it still a standard size disc? am also guessing that drilling will help too?

[boxsey]

Markh said:

boxsey said:

Rob, it's not advised to use 993C2 rears with standard 964 fronts because the pistons are too large and promote too much rear bias. The 993C2 rears are the ones that should be used when putting big brakes on the front at the same time. If just changing the two pot rears the calipers that can be used are 964C4, 993C4, 944turbo, 928S4 and of course late 964C2 (very rare second hand). All of these should also get the 55bar p/v as you say.

If I use the two pot rears, is it still a standard size disc? am also guessing that drilling will help too?

Hi Mark, I presume you mean if you use 4 pot rears instead of the standard 2 pot rears that are on most C2s? The same rear discs are used with all of the calipers mentioned here. Including the 993C2 rears I've been discussing with Rob and including the original 2 pots. The calipers will all bolt straight on to the mounting points and work with these discs. However, any calipers that came from a 944turbo or 928S4 will need the cross pipe moving to where the bleed nipples are and vice versa (because they were designed to mount on the opposite sides of the disc on those cars). Moving to drilled versions of the discs is an interesting debate. They may perform better but are prone to spider cracking from the holes, especially if used hard on track. Personally, I've not been impressed with the quality of so called after market 'sport' discs that are drilled because the drilling pattern is nothing like that found on original 964RS drilled discs.

[Markh]

boxsey said:

Hi Mark, I presume you mean if you use 4 pot rears instead of the standard 2 pot rears that are on most C2s? The same rear discs are used with all of the calipers mentioned here. Including the 993C2 rears I've been discussing with Rob and including the original 2 pots. The calipers will all bolt straight on to the mounting points and work with these discs. However, any calipers that came from a 944turbo or 928S4 will need the cross pipe moving to where the bleed nipples are and vice versa (because they were designed to mount on the opposite sides of the disc on those cars). Moving to drilled versions of the discs is an interesting debate. They may perform better but are prone to spider cracking from the holes, especially if used hard on track. Personally, I've not been impressed with the quality of so called after market 'sport' discs that are drilled because the drilling pattern is nothing like that found on original 964RS drilled discs.

many thanks for the info, the drilled bit is interesting, any idea if I can get factory drilled discs from Porsche?

[Wozy68]

barchetta_boy said:

Assuming you can lock the wheels up with the current setup, what are you hoping to gain?

+1 on this, unless you are a track addict, it's a lot of expense for not a great return IMO. I do a lot of fast driving on the mountain roads of the Pyrenees and cooked the brakes on just about every car I've driven there, other than in a standard Porsche (CS 968 and C2 993). Both of these were absolutely fine.
I'm sure I read in Adrian Streathers book on the 964 that upgrading to a turbo setup gave very little return for the outlay

[boxsey]

Markh said:

many thanks for the info, the drilled bit is interesting, any idea if I can get factory drilled discs from Porsche?

You can get the rears as factory drilled because they're the 964RS items (about £150 per disc). However you can't get factory front drilled discs for a 964. The 964RS factory discs are drilled but you'd have to upgrade the calipers (and fit adapters) to use them. So if you want to go factory drilled all round you need to do a front upgrade whether that be 964RS, 993 or big red/black (993TT/928GTS).

Personally, I'm of the same opinion as Wozy68 that the standard set up works well enough (especially with my car being lighter than a standard C2 and now that I've got cooling ducted in). OK, I get through discs and pads quicker than a car with big brakes but the initial outlay for a big brake upgrade pays for a lot of standard discs/pads and the consumables are a lot cheaper. However, we're all different and I can see why others prefer the bigger brakes for both performance and looks reasons.

[wildman0609]

the big reds from 993rs/turbo are not a direct bolt on replacement. I needed 993 rs uprights and steering arms. you can get a an adaptor to make them fit but i didn't want to trust that on a race car, and the adaptors are bloody hard to get hold of. i left the rears standard and its perfect for the racing i do.

the standard brakes were fine for the 15min sprint races i was doing but the big reds just hang on a lot longer and on a 45min race they are as good on the last lap as they are when fresh. i would'y bother upgrading if just doing track days or short races. they do look nice though.

[Markh]

Many thanks for every ones input, any idea where I can get the adaptors to fit the 993 brakes from, I guess I can get some made from billet, but if there is a kit available would be better


many thanks