mdrums

I don't know which forum on rennlist would be best to post this but I seem to find most of the track guys hang here and there is some great knowledge here.

I need some guidance and help fast.

Here is what I'm trying to accomplish with my 2012 Carrera GTS. My car has steel 997S brakes...same as 996TT brakes. My GTS has 4 piston calipers and 330mm rotors. I'm going through front rotors every 4 track days at Sebring. My friends with 6 piston calipers and 380mm rotors on 2010-11 GT3 or GT3RS that use the same pads as me go through front pads and rotors around every 14-18 track days.

I want to install 2010-2011 front GT3 center lock 380mm rotors and 6 piston calipers to my Carrera GTS which has the stock uprights. My Carrera GTS uprights are different than 997 GT3 or GT3RS uprights so the gt3 brakes do not fit with out some sort of spacer.

My local shop says they can machine a spacer and try to fit this brake system to my uprights but I'm seriously concerned about the spacers safety as ill be the 1st to test it out. I see Brembo, Stop Tech, Agency Power all have spacers for fitting big brake kits but these in my mind are company's with great knowledge and experience in metals and proper brake fitments.

Am I trying to do the impossible?
Will my abs still function correctly?
Will my brake bias me messed up?
Will my master cylinder work correctly?
Will the GT3 380mm center lock rotors and caliper have the correct offset on my 996 style stock uprights?


Again, I have a 2012 Carrera GTS with center locks.

NorthVan

IIRCwhen I looked at doing a swap on my C2S it required Turbo Rotors and GT3 Calipers to fit. I think your GTS will require a similar set up with a CL system. I ended up going to a 350mm Giro Rotor and they ended up lasting a long time. I am not sure if the CL will work with the Giro, if they do then that is easy, if not buy a Big Brake Kit. This is yours and everyone around you best option IMO.

GT3DE

Mike,

You should just change the whole front suspension tho GT3 parts. Then everything will fit correctly. There is a guy (scooter993 -Many GT3RS parts... parting out! ) parting out RS with a thread here in this forum. He is selling all his suspension and brake stuff as he is changing it into a race car. GMG and other shop are always putting up posts here selling takeoff GT3 suspension parts as well.

After you put the GT3 brakes on your car, as for the brake bias, change it (if different) to the GT3 bias factory setting. Or, if it were me, just drive it and see what happens.

v12man

Porsche make a spacer bracket that should fit for you using cup brake calipers with 225 mm hole spacing. (works with a 997turbo for sure)

Part number for that adapter bracket is 997 351 505 02 ( x2 ). Needs also 4x M12x1.5 bolts, 999 073 313 09

This bolts up together with the cup caliper and uses a 380mm GT3 disc.

I have a set of these on my bench, so let me know if you need measurements or photos.

Best of luck.

Larry Cable

haveyou checked to see if Stoptech, Brembo, AP or others have a kit for the GTS?

24Chromium

Personally, I'd do the Stop Tech kit (assuming they make one for your car) in a heartbeat! Better than what you're trying to do. Just ask all the GT car owners with Stop Tech's. I'm considering it myself.

mdrums

I haven't personally checked but my local shop where ViperBob is told me that these GT3 997.2 brakes for center lock would bolt right up...which wasn't the case.

So now they want to make up a spacer to make it fit.

mdrums

This Porsche spacer will space out a 997.2 GT3 caliper to fit a 380mm GT3 rotor onto 996 turbo gt3/2 uprights?

v12man

This Porsche spacer will space out a 997.2 GT3 caliper to fit a 380mm GT3 rotor onto 996 turbo gt3/2 uprights?

Yes - the 225 mm bolt spacing, 6 pot caliper - plug and play - test fitted to my 996 Mk1 GT3 - it is used on the PCCB 997 turbo - it is in the PET.

Of course, 18 inch wheels that fit 380mm discs are few and far between... mine had to come from Greece... a LONG flight south.

Nick Wong

Brembo. Just go with Brembo. Race Technologies build excellent kits, I've used them on other cars, fit and finish is top quality, they design their kits to work properly with OE ABS and e brake.

senna

I would not use a spacer, but that is just me. I would buy a similar size aftermarket kit that has been developed for your car. My 2c.

PAULUNM

Since you say your car has 996tt brakes- it's my understanding that 997tt rotors, and GT3 calipers front and rear should bolt right up... But that's onto a 996tt.

Here's a list of parts needed to convert a 996tt to GT3 caliper brakes, using 350mm 997tt rotors front and rear. Just keep in mind the 997 and 996 GT3 rear calipers have different piston sizes due to differing brake bias. So I assume you'd just use 997 P/Ns for the calipers instead of 996 as noted below-

996 GT3 MkII 2004> 6 Piston Caliper (left) 996 351 431 90
996 GT3 MkII 2004> 6 Piston Caliper (right) 996 351 432 90
997 tt Brake Disc (left) 997 351 405 00
997 tt Brake Disc (right) 997 351 406 00
4 X Caliper Bolts (8mm longer for 6 pots) 999 067 053 09
2 X Pad Wear Sensors 996 612 347 00
12 X Pad Damping Plates (6 per side) 996 352 086 02
Brake Pad Set (996 GT3) 996 351 948 00
Goodridge Stainless Steel Flexi Brake Lines SPR0801-4C
New Fixed Brake Lines - connecting flexi’s to caliper

NJ-GT

Spacers are a standard solution.

Fiat uses a 9mm spacer on the F430 Challenge, a factory race car, it is a stud with a spacer.

I use a 4mm spacer on my custom 405mm front steel rotors in my Fiat.

Brake bias is easy to adjust with different brake pads, when going from a front 330mm to a 350mm. But going from 330mm to 380mm will require some other tricks to fix brake bias.

The weight difference is significanrt from 330mm to 380mm.

I would go 350mm 997turbo rotors, custom cooling kit, and reuse the 4-pot calipers. Run a PFC06/PFC01 rear and PFC08 front.

But, I would instead get a 991S, powerkit, aerokit, PDK, and destroy all the Aero Beetles.

mdrums

All after market kits....Brembo, Stop Tech...etc...have a spacer to fit bigger rotors onto various uprights. A properly tested and designed spacer is not my big worry.

My worry first is what goes into properly designing a spacer and proper bolt length and strength. Plus will my brake bias and abs be messed up as I've read on some other forums by just making GT3 brakes into a system with a different master cylinder and abs system.

mdrums

Funny, I priced up a 991s with power kit, aero kit, PDK and adding the needed GT2 bucket seats....$145k. So that's gonna happen and should tell you what a 991GT3 will cost...$160k starting out.

So I'm trying to make my Carrera GTS better and fun for the next 4-6 years.

Back to the brakes...I'm getting confusing info due to uprights that 997.2 GT3 roots might not have the proper offset to sit in the caliper centered.