Fellas.....what am I looking at here?
I’ve never seen rotors look like this after a track day.
996Turbo with 350mm Girodisc front & rear......OE rear calipers, GT3 front calipers.
For this day I was using Cool Carbon Perf Pads (7892-D991 front, 7798-D917 rear). All was properly bedded in, or at least I believe so.

Front and rear Girodisc rotors had same appearance.
Thanks in advance.

 

Can you provide some details? Car, weight, track, air temps, etc.

 

Hey Dave,
So she's basically a heavy, modded 996Turbo.....that means around 3200 lbs, and close to 600HP. Along with the brake mods I mentioned above, car has GT3 brake ducts.
This was after 2 days at Rd America. Needless to say, that track has heavy braking on at least 3 of 14 turns.
Air temp was high 70s.
I run Nitto NT01 18s.......still experimenting w/tire temps&pressure as I come from Sport Cups.....but continue to have issues on this car with the rear wheels spinning forward in the tire (out of balance, power), and fronts spinning rearward in the tire (out of balance, braking). In past wheels & tires I've solved this with roughing up inside wheel and remounting using Sliptac (bead sealant).......working on that w/these tires/wheels.

 

Based on the picture it looks like you got the pads out of their heat range and they left a smear of deposits on the rotors. Swap in some abrasive pads and drive it for a while. Rusty rotors clean up a bit faster. Wash the car and get the rotors wet on all sides let the rotors flash rust overnight and drive. Repeat as needed.

Switch to a full track pad. I like Peformance Friction pads myself. Which compound depends on what you are looking for from the car and type of driving.

 

^ +1. Just some pad deposits. Drive on the street for a couple days and it will naturally wear off. Nothing to worry about.

-td

 

Pad deposits like the guys above mentioned. At worse, scoring from too much heat but Giros should be able to take the heat well.

Another option for pads are the Hawk DTC-60s or 70s.

 

Just a wild a$$ guess, you tell me if I am correct, but you've used other brake pads on these rotors before that were not the Cool Carbons, correct ?

Some brake pads do not like the mix of pad materials and do spots like that when it happens. The only full cure is fresh rotor and pad and proper bedding of both. Also the Cool Carbons are critical of bedding procedures.
I recommend PFC's because they are more user friendly and don't require as a demanding bedding process. But that's just my preference.

 

Appreciate the input so far fellas.

 

Sometimes with pad transfer to the rotor, it can cause a little vibration at high speeds. Your only complaint is the look of the rotor? I think that besides proper bedding another thing can cause pad transfer to rotor. Using brakes hard and at max agression on the warm up lap or out lap. Letting tires and brakes get up to temperature more gradually helps.

 

Could that also be caused by an 'off' resulting in some grit getting between the pad and rotor? 2 hard track days ... A couple offs would be par for the course

 

You've not mentioned brake performance during the event ... Were the brakes performing well?

I use PFC97 and have experienced no issues with brake pad deposits.

 

Appreciate the input guys.
So.....I'm starting to think C.Carbons was a mistake. I was just going to run them for an event or two to try. Like anything else....heard good things. Use to use Pagids for the track...yellow/blks and then change back to OE pads for daily.

OneFastViking......no, these C.Carbons were the first pad the Giros had seen. New set-up.
From the jump, after bed in, I was not that happy with their bite.....off the track.

And Dave.....per your question.....brake performance at the event, again they required more peddle than I'd like.....but worked. I had a 1 day event at a 2 mile track a couple weeks before and they were just 'O.K......and rotors looked fine.
But the most recent 2 days @ Rd.Am. were significantly heavier use. Also think my F/R bias is messed since the rear was a tad squirrely at times coming down on heavy braking. I need to loose that.
Throwing out the Cool carbons is $400. or so......anyone want a set?
Gotta get this sorted before next track day.

 

I've used Hawk DTC-70's with my Girodisc rotors (front only; OEM on the rears). They provide excellent intial bite, and I found the change in brake bias towards the front to be perfectly manageable.

 

More evidence of overheating them. Most pads start to lose their friction coefficient when they get too hot. I would suggest calling Porterfield and telling them the details of your car and tracks and they will suggest something out of Raybestos, PFC, or Hawk. They are really good with helping people pick the best pads for them, not just what everyone else runs.

 

Agree with above, I run the same - Giro on a heavily modded 996tt cab (heavier), I run PFC 08 front (still stock 4pod fronts) and 01 rear, great bias, if your running GT3 fronts go with 06's front - great pad set up for track,