As for clearance with the OE rear caliper and a 350mm disc, the attached image shows what I am seeing. This is the clearance at the ends of the caliper.

 

Some weight data for those interested:

996TT Original Equipment (Iron Disc)
Front Caliper with Pads: 10.1 lbs
Front 330mm Disc: 23.4 lbs
Rear Caliper with Pads: 7.9 lbs
Rear 330mm Disc: 18.9 lbs

996GT3/997TT Front, 997TT Rear Disc (Iron Disc)
Front Caliper with Pads: 13.1 lbs
Front 350mm Disc: 25.6 lbs
Rear 350mm Disc: 21.9 lbs

996TT/GT2 Factory PCCB
Front Caliper with Pads: 13.1 lbs
Front 350mm PCCB Assembly: 12.0 lbs
Rear Caliper with Pads: 7.6 lbs
Rear 350mm PCCB Assembly: 12.0 lbs

Brembo 380mm 6-piston Monobloc Front GT Kit
Front Caliper with Pads, Bracket: 11.9 lbs
Front 380mm Disc: 19.6 lbs

Brembo 345mm 4-piston Monobloc Rear GT Kit
Rear Caliper with Pads, Bracket: 8.9 lbs
Rear 345mm Disc: 14.2 lbs

Brembo 380mm 4-piston Monobloc Rear GT Kit
Rear Caliper with Pads, Bracket: 9.1 lbs
Rear 380mm Disc: 16.6 lbs.

 

Mark, This information is very VERY helpful. I know your initial posts here in this thread seem like you were getting beat up, But I for one really do appreciate your weighing in.

Mike

 

That's okay, I can take a punch

 

Anyone interested in making me a set of spacers so I can use the 997TT rotor/996TTcaliper set up in the back?

 

Scott, The liability associated with this really does make it a DIY for an individual. I've given pretty specific guidance on the dimensions and sourced the raw materials for anyone wanting to make a pair. It literally is an HOUR job in your home garage with the right tools.

I will not make spacers to sell, but can tell you it is a very easy mod.
Mike

 

Mark, I agree with Mike and again sorry for the BS.

 

No worries! Hopefully the info here will help someone out now or in the future.

 

Plop the 8006 rear calipers on a 996 Turbo and you will be a-lookin' for TROUBLE....

Porsche SPECIFICALLY mentions these lift-off calipers (which are unique to 997 GT2/GT3, and 997TT) are to specifically increase the rear brake bias.
Use on a 996TT would =

My 996 TT has had many a brake problem in the past - everything fixed with the GT3 front setup and NO changes in the rear except Pagid Black in rear and Yellows up front.

That is all you need to do.

~~ All information is from a 1 hour phone conversation with the brake pad guru Craig at www.Rennstore.com --- extremely knowledeable and experienced ~~

He helped me from hating the 996TT, to making it a formidable track beast I can whale on with abandon

 

I had the same setup you have, except for running pagid yellows in the rear, and although it worked well (and yes I had discussions with Craig as wel, good guy with good info), I found the 997TT rotor with the yellow pads provided a very balanced feel and staved off wear/ heat issues even more with lots more reliability and consistancy.

The blacks probably work well (I've not run them yet) but what others have told me is that they eat rear rotors much quicker than pagid Yellows. Running the yellows with the OEM 997TT rotor didn't show any acceleration in wear from my measurements... My rotors have 15 track days and about 5K street driven miles on them and are STILL the same thickness as when I bought them new from Suncoast... That's all I needed to see to know that from a maintenance and consumables stand-point, this is a HIT!!

Mike

 

Blacks in the rear are not a problem for me whatsoever - I've run this setup for 3 years and the wear rate is very low.
In fact the F/R balance is GREATLY improved becasue the rears are actually DOING WORK for a change ;-)
Probably because the rears only perform a fraction of the work of the fronts, eh?

Also, heat in the rear is rearely ever an issue - the OEM front 2474 size 996TT is a piece of crap when used hard, the rear 2405 OEM setup leave absolutely stock except for Pagids.

NO NEED for anything else in the rear.

75 hard track days, perfect setup.

FACT FROM FICTION.

 

Where are you located and which tracks are you running? Also, what rungroups and times? Just curious. That's an aweful lot of time on a set of pads and rotors, even if they are on the rear.

Mike

 

;-)

No, 75 day I've gone to over the years -

A set of pads lasts about 8-10 track days

 

I have 4 track days on my new brakes, 6 piston GT3 front calipers with Pagid yellows up front and Pagid blacks in the rear. The new 350mm front rotors already have 5mm cracks around the drill holes. The new 350mm rears have no cracks with the black pads and show no real wear other than transfer residue. Neither front nor rear rotors show any grooves yet. I wonder if the larger heat sink of the bigger rotor would slow down the grooving effect of the pads on the rotors. Seems to me I remember my stock rotors grooving from Pagid yellows the first track weekend I attended. What do you guys think? Maybe I'm starting to modulate my brakes more efficiently.

 

It probably has a lot to do with your growing skill as a driver.

What I notice is that when I have't been on track in a while, or go to a track I'm unfamiliar with, I tend to be more abusive on the middle pedal. These cars have such powerful brakes, generate such tremendous terminal velocity, and give such confidence that you can over-brake and throw to much heat into the pads/rotors/fluid rather quickly.

Mike