Anyone have any issues with cracking of the Girodisc floating 350mm rotors? I'm wondering if this was a manufacturing defect in the steel as the other side did not crack even though it is worn to the point of the slots beginning to disappear.

http://www.flickr.com/photos/87731073@N06/8196475187/http://www.flickr.com/photos/87731073@N06/8196475187/ by http://www.flickr.com/people/87731073@N06/, on Flickr

 

Wow- those are in BAD shape!! How many miles and track days them? What pads are you using- are these front? Do you have any additional cooling going to them?

I have bought new slotted rotors and PFC01 pads for my next swap- your picture is scary!

 

You are definitively taking this rotors to the limit... I think is normal due to the fatigue...

 

I would replace those pronto,it looks like they have been used hard and long past thier life span.

 

I have a total of 6300 miles on these rotors including 68 track sessions (about 20-25 minutes each). I used Endless pads for the first 27 sessions after which the pads were toast. I then put on PFC 08 on the front and the more aggressive PFC 06 on the rear to help shift the brake bias to the rear a bit. The 08s are PFCs "most gentle" endurance compound. The interesting thing is the fact that my rears are in great shape showing relatively little wear. Since I swapped from Endless I have put another 41 sessions with the PFC pads. The rear pads and rotors show little wear but I do NOT have PSM on my car, just ABS, so that helps. The front pads are at about 50%, so great life on the pads but at the expense of the rotors. The right front rotor has the slots almost worn away but no cracking. The left rotor, well, the picture speaks for itself.

I run RUF 6 piston front calipers and 4 piston rear. Basically a rebranded GT3 brake set up. I use the large 996 Cup car front cooling ducts and 996 GT2 rear cooling ducts. Whenever I have measured my brake temps after parking in the pits I normally see about 400F on the rotors and around 300F on the calipers, both front and rear, so fairly low. Obviously track temps will be much higher as these temps normally include a cool down lap. I will be retrofitting the GT3 wheel well spoilers to the car which will divert the radiator air to the center of the wheels when used in conjunction with the front GT2 fender liners. I'll see what that does but I don't see high temps as my problem. My friends 997GT3 for example sees much higher temps on his ceramics than I see on my steels FWIW.

Incidentally, I am not sure who recommended the PFC 01 compound to you. The 01 is PFCs most aggressive compound out of all the ones they have and is comparable to the Pagid black. The 08 is their most gentle (yeah right!) compound equivalent to the Pagid yellows. Based on what I've seen, I would not use the 01 compound if it were me, just my $0.02. I do love the PFC 08/06 combo as far as brake performance goes. Just surprised the front rotor with less wear than the other front rotor cracked.

 

I say try a set of coleman rotors. I have hear really good things about their rotors from numerous P car drivers. The can build you a new set for your Giro disc hats.

http://www.colemanracing.com/

Cheers EG

 

Wow, I thought you just got those, would be interested to know what the vendor who sold them says

(subscribed, am shopping for new rotors and pads for a similar brake setup).

 

I don't think its that abnormal to for a ring to crack after that many sessions. More is always nice, but not surprising after that many heat cycles. Other than the big crack, my 365mm bembos on my track car look the same with similar track time and are ready to be replaced. Going to try to do some improvements to my cooling.

 

That's what I'm thinking...

I track a pretty heavy car, and I'm good if I get 5-6 HPDE's (10-12 days: ~40sessions) per front rotor pair.

 

Considering I got over 23hrs of track use out of these I'm not complaining. My car is not quite that heavy. I'm at 3520lbs with fuel and driver but still not super light by any means and I drive the hell out of it on a high altitude brake demanding track. The work it that I may have actually shock cooled the rotors by not using the brakes enough on the cool down lap and allowing the rotors to cool at too quick a rate. Most likely going to go with 380mm brakes to provide a slightly larger heat sink as apparently I can still squeeze those under my CCW 18" track wheels. Right now I am running 350mm front and rear.