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it would help, although caliper/hydraulic bias change is the best/most effective way to do it IMO, I run a more aggressive rear pad as a track band aid solution currently but will upgrade to 997 rear calipers as my next move..
Running different pads is very effective way of changing bias, but is temperature/conditions sensitive...hydraulic bias is more consistent for a driver,IMO
I got my car with the Brembo GT 350-345 kit on it. It has the 6 pot front calipers with the bridge in the middle for more rigidity/pedal feel. I do not have a 996tt comparison but compared to my 99C4 that i also tracked the Brembo brakes are Awesome. They were simply flawless all day. The C4 stopped well but suffered from changing pedal feel and travel during the day and it had fresh motoul fluid and pagid yellow pads.
Do note guys on brake bias that's the calipers designed for 380mm rotors do have smaller pistons that a the 997 turbo/997.1 gt3 6 pistons designed for 350mm rotors. that accounts for the extra diameter.
Do note guys on brake bias that's the calipers designed for 380mm rotors do have smaller pistons that a the 997 turbo/997.1 gt3 6 pistons designed for 350mm rotors. that accounts for the extra diameter.
Here are the piston sizes to the various calipers. All the GT/Cup calipers have the zircon inserts. The TT calipers do not. Note that while externally visually identical, the 997 380TT and GT/cup caliper piston sizes are different on the fronts (larger on TT) and identical on the rears. Again, only the 997GT/Cup versions have the zircons inserts. Yellow colors indicate the calipers are used with PCCBs while red is for iron rotors. Cup calipers are identical to GT calipers except they do not come with dust boots. I would not recommend the 380 997TT versions due to the piston sizes and the piston material. They are also not rebuildable as PMNA does not sell a rebuild kit for the TT versions, only the GT/Cup versions.
380 calipers 997GT2/3/Cup..........FRONT/REAR BIAS = 53.9/46.1%***
Front 28, 30, 32
Rear 34, 34
***Using 996Cup ABS will shift brake bias further rear compared to the street ABS units as the Cup unit has a much higher lock up threshold programmed in the rear. A 997Cup has no ABS but has adjustable brake bias.
Slightly confused though, you list 996TT as 350mm, I thought stock was 330? I thought 350 was the 997 size? I'm not sure where I thought the 380 came from, GT2/3?
Slightly confused though, you list 996TT as 350mm, I thought stock was 330? I thought 350 was the 997 size? I'm not sure where I thought the 380 came from, GT2/3?
996TTS had 350pccb. I added stock 996TT numbers to post above
Last edited by pwdrhound; Dec 10, 2016 at 11:11 AM.
Sorry to revive an older thread. I have the chance to add the brembo gt 380mm kit to the car and will now need to get 18s that fit.
See that the BBS E88 and Finspeed will work, wanted to check if there was any luck confirming the OZ Alleggeritas?
Thanks!
I have the Brembo GT 380mm kit and there is some sort of a caliper spacer or something that makes the fit very tight at least on my car. The only 18" wheel that worked during a test try has been BBS Racing. For example, ATS GTR 18" wheels often used with 380mm BBKs on E92 M3s did not fit my brakes. Same goes for Alleggeritas. Test before you buy.
I went with 19" then. Another reason was lack of wide EU-approved 18" r-compounds. Except for Toyo which I don't like.
Sorry to revive an older thread. I have the chance to add the brembo gt 380mm kit to the car and will now need to get 18s that fit.
See that the BBS E88 and Finspeed will work, wanted to check if there was any luck confirming the OZ Alleggeritas?
Thanks!
Call TireRack. They have information on all the Brembo systems and are a dealer for those wheels.
Probably will be an issue on the diameter. In order to fit 380mm brakes in an 18" wheel, the barrel has to use a flat racing profile. Usually will only find that in quality forged wheels.
No idea on the aftermarket Brembo kit. The OEM Brembo 380 won't work.
Was glad to see this as I dumped a set of OZ that we're perfect other than I was swapping to 380 and nicer wheels. Figures though, no many upgrades are cheap or only require one variable.
After reading all this would it be wise to use the 997TT/GT2/GT3/Cup (Rear 34/34) calipers with 350 disc together with the 996 TT stock calipers (Front 36/40) + spacers and 350mm disc to change brake bias?
Right now i use the stock 996TT calipers with 11mm spacers and 350mm discs all around.
After reading all this would it be wise to use the 997TT/GT2/GT3/Cup (Rear 34/34) calipers with 350 disc together with the 996 TT stock calipers (Front 36/40) + spacers and 350mm disc to change brake bias?
Right now i use the stock 996TT calipers with 11mm spacers and 350mm discs all around.
You can but your brake pedal will be slightly softer due to the 50% larger piston area of the rear calipers. To remedy that you can install a 997 master cylinder but that will likely throw PSM error codes on a TT. You can disconnect PSM but that will cause other issues. It's a snowball rolling downhill....
Ok thx. I heard about problems when switching the master cylinder.
Then i will live with a softer brake pedal.
Important for me is, that the brake bias shifts more to the back.
