jranaudo

So let's say I run through a set of pads in 2-3 track days. Do I need to change out the rotors too or can I use them further?

For example if I go below 50% pads and change the pads before my next track day do I also *always* need to change rotors? What the standard procedure here?

Thanks!

Supercharged111

Standard procedure on track is to replace as they crack, which for me has always been long before minimum thickness is achieved.

StreetSpeed

Run the rotors til they crack. That will be somewhere between 2 days and never, depending on everything.

ErnieN85

not just visable cracks but when you can catch a fingernail in it or the crack extends all the way to the outside edge

Zenak

Agreed. Spider cracks are totally normal and fine. Its GOUGES in the rotor, and any crack that opened up the edge of the circumference as these can cause a failure split from teh edge to the center of the rotor. when this happens your done. The rotor warps and every time you step on the pedal YOU WILL KNOW. then its come in and emergency swap in the pits... lose time on the track. Also its a good idea to ROLL your car in the pits. When the rotor cools, the space by th pads cools slower since the air doesnt get in there. As metal cools un evenly - the metal can warp and creat larger cracks. So bring the car into the paddock, then wait about 5-8 mins and then roll the car with your hands in neutral about 6" - just enough that the rotor under the pad gets fresh air and can now cool at equal pace with the rest of the rotors.

Dan H.

How often do you crack a rear rotor versus a front? I'm guessing fronts crack more frequently, but this newb is still waiting to crack his first rotor .

Supercharged111

I cracked a new rear on the vette once in 1 weekend, I think it was a fluke. It was always the fronts for me. Now the Camaro? Pretty much never out back, fronts just as consumable there. I seem to get about 3 weekends on a pair of fronts.

jranaudo

Thanks guys. Will be checking them today.

Bill Dearborn

On my C5s the fronts cracked more often than the rears but not that much more often. I always took two spares for each rotor position.

On my C6Z with the stock brake system the fronts and rears cracked about every 5 track days. The fronts would go through the normal heat checking process and let me see when they were about to crack while the rears never got heat checks but suddenly cracked.

When I went to AFX/Coleman heavy duty two piece slotted rotors the fronts cracked about every 7 days and the rears never cracked. I actually wore out the rears. When I got rid of them the slots were no longer visible and the rotor was below its minimum thickness.

Now that I have Wilwood front and rear I am getting ~ 15 days on the front and have 18 days on the rear rotors. I have had the rear Wilwoods on the car since July 2013 and they are just now starting to show some heat checks.

Bill

JeremyGSU

I have the AP T1 kit on my C5 Z running slicks, SKF hubs front and rear, brake ducting, LG spindles, XP20/XP10 pads, stock rear calipers. My home track is Sebring.

I get around 4 days on my front rotors before cracking and 5-6 days on the rear.

94boosted

So you're saying I shouldn't really be too concerned about these tiny little cracks that appeared just after my last autocross event in my front rotors?

ErnieN85

not yet that is normal and ok

SunnydayDILYSI

Those look OK, but I'd go with solid or slotted rotors in the future. Drilled rotors are going to form cracks to the edge more quickly as the cracks tend to connect the dots.

ZedO6

If they don't develop cirumferential cracks sooner (outer edge to inner), when 3 holes are connected by cracks, toss em. Make those your last drilled rotors for track use.

StreetSpeed

Are you using stock rotors with the AP kit? I have like 30 days on my J hook full floating rotors. They're about done (J hooks are almost worn off) but if you're cracking THOSE rotors in 4 days then that's crazy talk.

94boosted

Thanks guys, good to know. I've been proactive and ordered up a set of DBA 5000 Slotted Rotors just to safe. But I'll use these or just a little longer.

JeremyGSU

J-Hook rotors. 4-5 days. Sebring is VERY hard on brakes. I could probably get twice that life at Road Atlanta.

ZedO6

That's on slicks, which impact brake performance significantly.
Are those stock diameter, 12.8" rotors?

JeremyGSU

Yes. Continental GTI slicks. Yes, they are 12.8" rotors.

I think it's a good kit but if I had to do it all over again I'd get a Stoptech 14" kit, maybe the Trophy's. Unless you are racing a specific class I would not get the 12.8" kit. It's just too small and can't get enough cooling IMO. I always track with my buddies and they have a C6 Z making 540whp and an M3 about the same speed as my C5 Z. Both of them have 14" Stoptech kits. I brake harder than both of them and when I come in my kit is sometimes smoking whereas there's are never. Both of them can also reel me in on the braking zones too (hard) and I hit the pedal as hard as it will go. Nothing left. This is always at Sebring. I rarely track other tracks.

skxf430

What brake pads are you using?