knfeparty

Running street tires. Ferodo DS 2500 pads in the front and Hawk DTCs in the rear with ATE super blue fluid. Probably less than 500 miles on the pads and fluid. At FIRM, which is a 1.5 mile track with two straights, I was reaching around 110 on one straight and around 100 on the other. I had to start driving more conservatively because I was getting some fade. Not "oh crap" fade but it was definitely there. Now my back brakes sound like they are constantly scraping and the back left pad turned white over about half of the pad and the back right just a bit of the edge towards the rotor. Also on the outside of the rear pads there is bubbling in the finish/film on the outside of the pad. The rotors themselves look almost polished and the cooling holes are a bit clogged with brake dust. Even the rear fenders have a fine film of brake dust on them.

When I installed the new pads the rears had little clips that went into the brake caliper pistons and were glued onto the pad. My new pads didn't come with these, nor could I get the new pad installed with the old clip things due to the lack of clearance between the piston and the rotor.

Sorry for the huge pictures. First 4 are back left x2, back right x2, then the last one is of the front left for reference.

Can anyone give me some guidance?

Carrera51

The rear pads look like the got cooked. Which DTC? 60 or 70? Were you getting into the ABS? Does your car have PSM? What model? 997 or 987?

Steve Weiner-Rennsport Systems

Yep,....pads are grossly overheated since those Ferodo's & Hawk's are inappropriate for track use. They simply were operated beyond their max temperature range.

Those "little clips" are the factory anti-vibration dampers and their sole purpose is to reduce brake squeal.

JMHO, but if you install some GOOD race pads, you'll not experience the fading from over-temped pads. I prefer Pagid RS-29 Yellows for cars like yours.

knfeparty

It's a 40th anniversary 996 equipped with PSM which I left on and drove smoothly enough as not to activate it. I was threshold braking for some sessions but never diving into ABS. If a HAWK DTC can't stand up to HPDE then what the heck is it designed for? The Ferodos in the front don't look bad and I have run them forever on my BMW with no problem.
So I am good without the "little clips" then?
This car is street/autox most of the time and sees maybe 1-2 HPDE per year.

Hardback

Buy PFC 08. Braided steel lines, gt3 ducts, better fluid ...Motul or Castrol or endless. Hawks are useless to experienced driver.

philooo

+1000

just do what he says

Carrera51

The Hawk DTC 60 and 70 are competition pads and pretty popular some racing circles. I raced on them once in a borrowed 944T at VIR and they performed well. Looking at the photos of the rear pads, they definitely got very hot. Did they feel like they were dragging at all? The last time I saw a rear pad that looked like that, it was on a car where the rear pads were dragging and they got cooked.

I don't have any experience with the Ferrodo DS2500 pads so I can't offer any insight there. The DTC70 is a high torque pad. If the DS2500 has a lot less torque, the other possibility is that the DS2500 couldn't keep up so Hawks were giving you too much rear brake and as a result the rears got too hot.

I concur with previous posts. Switch to a better brake fluid. You should flush out the ATE anyway given how hot things got. Can't go wrong with any of the fluids Hardback mentioned.

Yes the PF08 is a great pad! They are not available yet for your rear calipers so you could run PF08 front and PF06 rear. Great combo on your car.

knfeparty

Thanks for the input guys. How do I tell if the pad is dragging and if it is, how do I fix it?

I use the car primarily for stock class autox so the brake cooling ducts and braided brake lines are not feasible as they aren't allowed. Should I be concerned about my rotors? I'm not enthused about the idea of throwing away $500ish dollars worth of new brake pads nor do I want to just throw parts at this problem. I even ran stock pads on this car for several sessions at NCCAR, which has straight speeds up to 150 running counterclockwise, and did not see this kind of heat in the brakes.

dotframe

Wow I spent many a track day on my OEM pads with motul fluid and never had such problems. Can't remember, does the 40th have turbo brakes?

M3BimmerBilly

Not enough airflow. The track configuration is the problem. Its so short that there is not time between braking sectors to stabilize the brake temperature.

Bring the car to a place like Road Atlanta where the speed/distance is enough to build a consistent temperature in the brakes. You wouldnt suffer the same problem.

cannon1000

I could go an entire weekend no problem at Road Atlanta. Cooked my brakes, boiled fluid and got the pad so hot it separated from the backing at TGPR (aka. Little 'dega).

Small tracks are brutal on heavy and fast cars.

knfeparty

I've been to Talladega GP, and FIRM is only a bit bigger but has way more speed. NCCAR on the other hand only has one big braking event; the main straight. So I think you guys are definitely on to something in regards to short track with a fast car. I am going to put the stock pads back in the rear for the mean time to see if the scraping sound I've been hearing goes away. Also, those anti-squeal dampers/clip things are no longer used? I went to the stealership and they didn't have them i.e. they have been superseded.

fpena944

One other thing to check, although I don't know if this is an issue with you or not, is the backing plate could also be causing some of the rubbing noise.

I remember leaving a DE event once and hearing rubbing coming from one of my rear wheels. I checked and found that the heat (or maybe some debris?) had caused the backing plate so ever so slightly begin touching the back of the rotor. I used a screwdriver to bend it back into place and the noise was gone.

knfeparty

I'll check the backing plate; you mean the spring that holds tension on the pads? I just finished bleeding. The fluid that came out of the calipers was cloudy. There is a lot of pad deposit on the rotors and I think that might be causing the sound. I am going to take it for a drive and try to get some of the pad deposit cleaned off the rotors. I also used my caliper to measure the rotors; on the outside surface I have a 1.1mm lip on the outside. I am assuming this equates to a total of 2mm wear and means that I need to replace the rotors. Any suggestions for rotor replacement other than OE Porsche ones?

knfeparty

I cleaned the rotors by doing the regular brake pad bedding procedure as best as I could with the traffic around here. They definitely have less deposits on them now but aren't totally clean. Scraping/squeaking noise significantly diminished but still there.