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Discussion Starter #1 (Edited)
Doing a track day 3/7 with PTV 6sp,SC,running 25min sessions, CT XP10 pads. Don't want to cook the rear calipers and have them turn colors. Im trading the car in july when the GT4 comes in . Will the rears hold up?Running button willow 13 CW. Three hard braking zones 115-60 per 2min lap. thanks carl
 

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I'm getting there... It took me 4 track days and about 600 track miles to get it slightly discolored...
on on PFC 11 and rears are starting to turn darker red. I would just repaint the caliper before I return the lease...
 

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Turn the stability management system off - or on low, whatever the 981 has - and you will reduce or eliminate the issue. The heat does not come from hard braking, but from the stability systems intervening. Also, it seems to be much worse on cars with Hoosiers, etc. Cars with street tires cant hold the same slip angle and the car seems happier.

Cheers,
 

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Doing a track day 3/7 with PTV 6sp,SC,running 25min sessions, CT XP10 pads. Don't want to cook the rear calipers and have them turn colors. Im trading the car in july when the GT4 comes in . Will the rears hold up?Running button willow 13 CW. Three hard braking zones 115-60 per 2min lap. thanks carl
After 9 track days on the RS29 rear pads, they are at 75% with no rotor cracks or discoloration. I think Hoosiers,BFG R1s and the like are more likely to give you cooked rear calipers. You might want to get the heat decals for your calipers or a cheap IR temp reader used in the pits to let you know what is going on heat-wise.
 

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Thanks everybody! Sounds like 3or 4 track days with the PSM off will be ok. I've read some people have trouble with the seals in the calipers.?Is it just the dust seals on the pistons or do they leak? Anybody have pictures? Kind of Pi--es me off .I had an AudiTT RS 3350 pounds the brakes got really hot but held up running Raybestos ST43s. It looks like there's a reason they put 15 inch rotors on the GT4. Carl
 

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even if they do turn brown the dealership shouldn't give u any fuss about it
 

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A few years back, the silver calipers on my CLK Black Series turned gold from track use. My SA asked about it and I told him I ordered the "gold caliper package".
He nodded and said, "Ah".
 

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Thanks everybody! Sounds like 3or 4 track days with the PSM off will be ok. I've read some people have trouble with the seals in the calipers.?Is it just the dust seals on the pistons or do they leak? Anybody have pictures? Kind of Pi--es me off .I had an AudiTT RS 3350 pounds the brakes got really hot but held up running Raybestos ST43s. It looks like there's a reason they put 15 inch rotors on the GT4. Carl
FYI: PSM never really goes completely off AFAIK. As soon as you get into ABS PSM becomes active again.

Looks like a lot of people who run PDK seem to have a larger likelyhood of not been able to do threshold brake properly. Probably because they are not heel and toe downshifting which usually requires a bit better braking technique without getting the car into ABS to not upset the car while downshifting.

The GT4 will be like your previous 996.2 GT3 (there was no Porsche Save Me), there will be a mode that will disable PSM completely just leaving ABS active :dance:
 

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.... The GT4 will be like your previous 996.2 GT3 (there was no Porsche Save Me), there will be a mode that will disable PSM completely just leaving ABS active
My understanding is that the GT4 will have rev matching built in .... all that heel toe practice goes to waste.
 

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My understanding is that the GT4 will have rev matching built in .... all that heel toe practice goes to waste.
Yes you are correct, the GT4 will have rev matching built in, fortunately it can be disabled as well :dance:

Some folks are already thinking about the possibly of getting the gear sets changed. As Grant mentioned a while back, if the rev matching can't be disabled that would cause a gigantic headache due to the DME trying to match to the stock gear ratio's.

My biggest concern is in regards to PTV, hope that it can be disabled to prevent the rear brakes from dragging. Also it would be nice to be able to upgrade the LSD without having to worry about having to deal with PTV getting confused.
 

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I am starting to think that I am glad that I skipped PTV... Cayman S is a weekend / track toy for me. Macan S is DD.
 

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If you can get an under sized 20 mm 981 rotor in the caliper with 2 mm of titanium shims for a total of 22mm, is it possible to fit a 24 mm 987 rear rotor in the 981 rear caliper. In fact are the rear calipers the same for a 987 and a 981? That would put a little more mass in the rotor to help handle the heat.
 

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OK. I gotta ask. On these brakes where they turned brown, what % of pad thickness remained? The pad itself, and not the metal back plate, is the only thermal insulation between the heat and the caliper assy's. If you run the pads thin, u are inviting overheating problems in ur caliper assy's. If I tell me u had at least 60-70% of full pad thickness, then I'm inclined to believe the rear brakes are too small. Otherwise, I'm going to recommend u change ur pads more frequently, at least by the time they are 50%.
Running with thin pads is asking for caliper overheating problems.
 

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here is what i found out with the shims in the rear and the front..

Rear there is still about .5 to 1 mm wiggle room, with R14 blacks in the back




the front with rs29 is a bit more tighter




hope that helps..

Lemon
 

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Thank you Lemon. The pictures are great and very illustrative, especially with how the shims look in there. Thanks for your prompt response. It still looks like there is 3-4 mm on each side of the shim before you hit the caliper body. Could the pistons be pushed in any more and allow for a thicker rotor or are they already fully compressed. The 24 mm 987 caliper and the 20 mm 981 caliper have a different offset so are not compatible, but if it would fit, maybe Giro Disc could make some for us. Just a thought?
 

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OP i would advise you do not turn PSM off if you're only trying to conserve the coloration of the rear brakes. Its better to have discolored brakes than to have your car fling into a wall.

I don't know your track experience, maybe you're an awesome driver and don't need PSM. But if you consider yourself anything less than a professional, I advise keeping stability management on and with sports plus
 
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