Fly911

After around 50 track days, the front rotors (OEM stock) on my 993 has started to crack around the cross drill holes. The cracks are 2-4mm long, and have been developing over the last couple of months. How far can I go before the cracks will be dangerous? Are there anyone who have experienced rotor failure due to cracks?
I have fairly new Pagid Black pads, do I need to change them when I change rotors?

Gary R.

Count yourself blessed getting 50 track days out of a set of drilled rotors! When the cracks approach other cracks or the outside edge of the rotor junk it. I've gone from solid (OEM), drilled, frozen slotted, and back to OEM.

Veloce Raptor

What Gary said.

I recognice LSR PCA and Maverick PCA run group stickers on your windshield. Where do you live?






Professional Racing and Driving Coach

Fly911

Sorry, I was brain dead for a second, I forgot that I have only tracked this car for a year (my previous track toys are sold), and I don't have 50 track days on it. It's more like 15 track days...

The cracks are no way near to aproach each other, nor near the outside edge of the rotor. I was planning to do one more DE (white run group) before Chrismas, and then change before the 2010 season. Am I running a big risk here?

And to Veloce Raptor, I live in Houston, Tx, and those stickers are LSR PCA and Hill Country PCA.
BTW, the butt of that girl on the picture is (nearly) more sexy than the butt of my 993...!!!

Flying Finn

Doesn't sound like you are but it's not only when the cracks go from one hole to another ot the edge when the rotors are done. See the factory info below.

Besides the factory info, I've followed "if you can stick your fingernail in to a crack, your rotor is done" rule. Usually the cracks go from hole to another or the edge before but once or twice I've been able to stick my fingernail into the crack before that has happened.

Geoffrey

It is best to use used pads with new rotors and the Pagid RS14s (black) are one of the most agressive pads on rotors and will crack them sooner than other pads. However, they have great bite and are an excellent pad for maximum braking capability.

Fly911

Thanks guys!
My rotors are in between the first and the second picture posted by Flying Finn. I believe I can use them for one more track day, and then I will change for a new set.
I see that FVD has 993 rotors (OEM?) for $120 per rotor, any thoughts? Are there any rotors out there that I should avoid?

Flying Finn

Make sure they're OEM's, NOT Zimmerman's. You recognize OEM's from the fact that the hats are painted.

I'd get them from a dealer, one of the on-line such as Suncoast.

chrisc

Curious, what's wrong with Zimmerman's? I've found they're the best for my track dog 924S.

Gary R.

For some reason I thought Zimmerman WAS the Porsche OEM manufacturer?

Gasser

Or just use some of these 13 inch beauties. custom aluminum hats. These are by Brembo. Full floating design. Custom hats for 993 C2.

KOAN

Zimmerman is an OEM, but they make rotors of different quality, IIRC. Porsche rotors from Sunset or Suncoast are not that expensive, and you don't want one shattering. I have seen that happen a few times, and the results are...memorable. On my 993, pagid blacks were great at stopping, but pretty hard on rotors. I switched to RS brakes and the rotor life increased 50%.

A930Rocket

Is that a left side rotor? Just trying too get the rotation oriented right.

Gasser

no, its a passenger, right side rotor... Look at the center vains, the orientation is right. This is the same disk that is used on the NASCAR cup cars. Only thing custom is the center hats...
We used 1/2 inch spacers to move the caliper out and had to machine off a little to get them to work on the 1 inch larger disk. Pad area matched up perfect with these. Custom cooling backing plates as well. 450CFM pumped through the rotors using powered fans. Lot of work though...

m73m95

^^ Where would somebody get those made?

Can you buy the rotors, and the hats online.....separately?

Would it be possible to make some really narrow hats for early offset 944's?