MJones

Porsche has the best brakes.

You say the rotors must be replaced...has the tel-tale gone below the rotor surface?
Is the surface smooth or marred?

My first guess is your braking / driving technique is mostly the problem. (significant over-braking)

How new or old were the pads when you started??
How thick were they? Do you know?

Street pads don't like the heat
Are you running "Race Pads" There is a TSB addressing that issue

mdrums

ahmet, I do understand what you are saying but now that I brake lighter and not threshld braking every single turn I am actually doing faster laps, carying more speed. It's hard to argue with Hurley Haywood when he says you are braking too hard...lighten up, save the brakes. It worked for me.

Z06

Do you have the stock PASM shocks.. system?

Is everything pluged in no melted wires/shorts and working okay related to the PASM?

There are two sensors, one on the front and one rear that measure ride height and the road conditions...smooth or bumpy track/road surface.....anything like this can cause the computer to go into a limp saftey mode that could cause this.

Targa Tim

nothing is wrong with your car, or your brakes.

the problem is you...as you are a ghost-rider.

neros

The quarter sized tel-tale is perfectly visible. The actual rotor surface is smooth. According to the dealer, it needs to be replaced. The first time the brakes melted it had original pads, the second time it had the upgraded track pads. The pads were basically new. Remember the brakes melted once and I had to change everything (calipers and pads) at 1,000 miles or so. The second pads had some light street use and one track day. They disintegrated on the second track day.

How do you over-brake a car? If you're going deep into a braking zone and braking late, you're trying to slow down in the shortest distance possible without overcooking the turn. You're going as fast as possible and slamming on the brakes until the threshhold right before the ABS kicks in. Your braking is always limited to what your tires can handle given the conditions and how well your brakes are holding up (these brakes never show signs of fade until they fail). I usually brake late and trail brake into turns but always under control. I can't see how any technique would change the amount of work a brake has to do. The difference between a normal braking point and a late braking point is 50 feet or so and it comes down to how well you can trail brake but the braking distance will usually be the same more or less. You can slam harder at first and then trail or vice versa (which is not what you're taught at racing schools) or you can slam on the brakes so that you're always braking hard until you trail off for the turn.

Lets assume I have the worst technique in the world for one second, I still think the brakes should last more than 1 track day with 3 30 minute sessions. These are not race conditions are any prolonged abuse of the brakes. These are driver event laps with a lot of traffic where out each session you get maybe 2 full speed laps. I constantly run with GT3 Cups, 997 Turbos, Vipers and Corvettes which run at similar speeds and have similar braking points and whenever I brake behind them, we have similar braking points and speeds. There is never anything unordinary about how I brake compared to other people on the track. I also drive a 996 Turbo with more horsepower than the GT2 and I have never had problems with brakes.

The whole situation comes down to the fact there is a flaw in either the traction control, the brakes, or a combination of the two. I think
I definitely push the car to the limits but that is why I bought a GT2 instead of a GT3 or Turbo, to be able to push the car on the track.

neros

Everything is stock and all wires and everything were checked after the first failure. Homestead is a very smooth track and so is Palm Beach.

C.J. Ichiban

I think because this is such an extreme case, most of us who use PCCB on the track regularly are having a hard time understanding it- but the simple fact is that yes you are correct- even AWFUL technique should not degrade the entire system in 90 mins of tracking in one day.

my RS had a lot of life in the brakes at all sorts of tracks and never had any issues.

Personally- I think your particular car or assembly might be to blame, perhaps something really is wrong with your car that hasn't popped up because it's an individual issue. I would suggest taking the car to a friendly dealer (one who understands that track days are okay) or a friendly independent mechanic to really figure out what the hell is going on.

in the last 3 years of reading about the PCCBs I've never heard of someone experiencing caliper issues- just rotors and pads or pads and fluids.


this is really weird and I'm sorry.

NJ-GT

neros,

There is something wrong with your brakes. The color on the rear calipers means the got to really high tempereratures, I have seen GT3 Cup calipers turn brown, but after years of use.

I doubt that with 6 years of experience at the track, you could be doing something wrong with the brakes (braking technique).

From the pictures, the rotors look like they have plenty of wear.

Switching to cast iron rotors (they are available) is not going to fix the problem.

Other than the electronics doing brake application on the rear even with TC/OFF-SC/OFF, I don't see how the rear wear can be that extensive.

If the Porsche warranty doesn't fix your problem, you could consider upgrading (yes it is an upgrade) to Brembo GTR, proven racing brakes as light or lighter than the stock PCCB. Stoptech is running a new system in the 997 Cup that fits the 997GT2, quite light and race proven.

Unfortunately, I don't see how you can improve cooling to the rear brakes, as that would require body work.

MarekN

One thing wasn´t mentioned here yet - the rear brakes on our cars run hotter than the front. One reason is that between 996 and 997 there is more rear brake bias in the newer cars.
Another fact is that in the 911 all hot things are in the back right by the rear brakes - engine, transmission, exhaust - so you have 500 or 600 pounds of hot metal sitting there radiating heat constantly, which does nothing for brake cooling.
On my GT3, whenever I stop and check the brake temperatures, the rears are always hotter, which is the other way around than you would expect.

The 38/62 weight split enables the rear pair of wheels to do a lot of braking and that explains why Porsches are so good at this, but this same fact also goes hand in hand with the above and may explain why many owners report that they change rear pads more often or as often as the fronts. With regular cars the frequency of changing rear pads compared to fronts is about 1:2, because the front brakes do about 70% of the work and also the weight transfer in front-engined cars lightens the rear wheels to such and extent that bigger brakes wouldn´t work anyway.

This is nothing new for any of you, I was just summarizing what came to my mind.

sasportas

Have you considered switching tires? The OEM Sport Cups may be inducing a great deal of "over" computer assistance. Go with Hoosier R6's in the 19 inch size.

Snowboarder54

Greygt3

Can't wait to hear the conclusion of this. I'm of the opinion that there is a issue with your braking system. I can't think of a scenario that would go through a set of pads in three thirty minute DE sessions.

MJones

Did you inspect brake pad thickness prior today two???

Not impossible to go thru a set of pads in a day or not have enough to carry you thru day two...

rodjac

I just came back from three days in the heat of Buttonwillow (about 93 degrees) and didn't have this kind of problem. We ran 30 minute run groups so there was plenty of time for the brakes to get really hot. It almost seems like your pads must be constantly pressing against the rotors and thus generating a lot more heat than normal. I would vote for some kind of defect in the system which calls for trouble shooting by a really good brake guy.

TrackDays247.com

Man this entire situation is quite odd. I've never seen nor heard of anything like it. Never seen the huge GT3 brakes do this, ever ......

1) The rear brakes are working about 4X as 'hard' / often as the 996 GT3/GT3 brakes - the rears typically wear out TWICE AS FAST AS THE FRONTS vs. front twice as fast as the rears on nearly every other Porsche made, including the 996 GT2/GT3.

2) Let's have a look at your pads. Pictures?

3) What specifically WERE the "track pads" that were installed the 2nd time?

Get a good analysis / dealer workup on this pup.