deputydog95

Karl, did you do front and rear, or just front?

If you are doing the rear, do they just bolt up or do you need the aforementioned parts for the rear too?

pete95zhn

BTDT, got pictures. Will post some comments later.

pete95zhn

OK. First what I've found out playing with these brakes, intially with my 951 and later with this C2.

FRONT
1. Hubs ( in this context hub means both wheel carrier and actual hub ) match with discs, caliper offsets are the same. Ie. if you use hubs from a turbo, you must use discs from a turbo. Independent of disc diameter or origin of caliper. However if you have hubs from a GT3 or GT2 ( which is actually a GT3 hub ), you can use turbo's disc with a 1.5mm shim between the disc and the hub.

So for a C2 use GT3/2 hubs with GT3/2 discs. Or 996 / 997 turbo disc with those 1.5mm shims. Calipers may be either from a GT3 mk I or II, GT2, 996 turbo or 997 turbo.

For a C4 use turbo's hubs, discs either from 996 turbo or 997 turbo. Calipers per your preferred colour...

2. Suspension. GT3/2 wheel carriers match with C2's struts. Turbo's ones with C4's.

3. Wheels. Anything with offset more than 45 mm interfere with 6 piston calipers. 18" is a must.
If you use 4 piston calipers with 330 mm disc, you may do with 17" wheels, but not with all of them...

GT3 mk I disc and 996 turbo disc = 330 mm
GT3 mk 2 disc, GT2 disc and 997 turbo disc = 350 mm

REAR
All 330 mm discs mix with all calipers meant for a disc of the diameter. No need to change hubs/wheel carriers.

My own set is a mix of GT2 wheel carriers, 997 turbo front discs and 6 piston calipers ( and those 1.5 mm shims ) at front. Rears are from a 996 turbo. 5 mm OEM spacers at front.

When buying an used set of front wheel carriers, be sure that they come complete. And change bearings before assembling them.

I've did last summer about 150 2-mile laps with that set without problems and the mastercylinder, brake booster and ABS unit are original C2 parts.

deputydog95

Great post! Thanks for all the info.

nick49

I looked into this several years ago, bought F&R TT calipers, hub carriers, hubs and all hardware to do the conversion. I then started researching a bit more and used my knowledge from setting up roadracing motorcycle chassis, suspension, and brake systems. I make my living working on them, BTW.
Anyway a couple of critical points: The TT and GT3 calipers have larger pistons than the C2 or C4 and can displace a lot more fluid as the pads wear down. The TT and GT3 master cylinder pistons are larger as well to yield a pre determined effort vs. travel @ pedal ratio. The Fluid reservoirs are much larger as well on the TT and GT3 larger yet. Under the right conditions braking failure could occur if the pads wore sustantially and the reservoir became delpeated of fluid. If you must fit the larger calipers, fit the approiate master cylinder and reservoir as well.

The real reason and most important one for not fitting these brakes is the fact of adding more unsprung mass to the lighter duty C2 front suspension didn't make any sence. If the cars power was not greatly increased, to add a lot of unsprung weight to the suspension seemed like I was going backward performance wise. The stock calipers are great for a stock or lightly tweeked motor. Learn to drive better and go pads with a higher CofF. I agree the Big Reds look pretty awsome, but after some thought, I concluded maybe they look awsome, but only to those that don't know the whole story. From another thread," I'm a much less is much more kind of guy".

deputydog95

More great info! Thanks Nick.

My car is supercharged and running around 420 to the wheels. It would be nice to have a little more braking oomppphh at the track.

Your thoughts on upgrading the MC make sense. Seems like the right way to do this would be to get the MC, calipers, rotors, wheel carriers, bearings etc...

For those that are doing the GT3 or TT upgrades, are you doing the rears too? Seems like it would change the brake bias significantly if you just did the fronts.

I wonder how they do it with the Brembo and Stoptech BBK kits as they use the stock MC??

pete95zhn

996 C2 / 996 turbo / 996 GT2

Brake booster ratio: 3.85 / 3.85 / 3.15
Master cylinder diameter, mm, F&R: 23.81 / 25.4 / 25.4
Master cylinder stroke, mm, F&R: 18.0 / 18.0 / 18.0
ABS all: 5.3
Pistons, mm: 40-36 / 44-36 / 38-32-28

Brake fluid reservoir, MY '01:
C2: 996 355 013 00
tbo: 996 355 013 47
GT2: 996 355 013 00

PFPADM

I would like to install the 996 Gt3 MKI brake set at my 996 C2 2000.

So please what pieces I need, in order to mount this brake set?

Thanks

PFPADM

I forget to tell, I have the 996 GT3 MKI, wheels, in 8' ET 52 front, and 10' ET 65 rear with a spacer of 7mm, front and rear.

TrackDays247.com

For GT3 Mk1 pads: 996 front pads are same as rears for Mk1 GT3, fronts are Pagid 2707.
Have both in stock if you are doing track work - which I assume you will be with these honkin' brakes.

PFPADM

Any answers?

I need to know if that is possible, to change the brake ssytem, and what I need to buy to do the conversion 996 C2MKI > 996GT3MKI ?

For now I think in the front only.

It needs only calipers , pads and discs of 330mm?

Parts:

99635140991 DISC TRV FRT Left 996GT3
99635141091 DISC TRV FRT right 996GT3

99635142910 Caliper Breaks FRT Left 996 GT3
99635143010 Caliper Breaks FRT right 996GT3

Pads , I don´t insert the codes because there is so much options, in other brands.

deputydog95

You need to do front and rear.

You also need the master cylinder.

Lastly, you will need rear calipers and rotors, as well as front rotors, calipers, and wheel carriers.

I did this conversion about 2 years ago on my 02 996 C2. Huge difference at the track.

jrgordonsenior

DD95,

Did you by chance weight the different setups per corner? Would love to know the actual difference as I've heard anywhere from 5-15 lbs. per corner....

PFPADM

Thanks a lot.

Can you help me in this:

1- Can Ì do this by steps? First in front, and then at rear? Or I have to do the full conversion at the same time?

The rotors are the discs? Or are another piece?


Can you give the codes numbers of the pieces I need:


- Master cylinder
- front rotors
- front left calipers - 99635142910 Caliper Breaks FRT Left 996 GT3
- front right calipers - 99635143010 Caliper Breaks FRT right 996GT3
- whell carriers - front left
- Whell carriers - front right

- rear rotors
- rear left calipers
- rear right calipers
- whell carriers - rear left
- Whell carriers - rear right


Thanks

deputydog95

I did not weigh them. But they are bigger, so therefore heavier for sure.