cj68

I have been running stock Z06 pads and my front rotors have a developed a lip on them. I am going to Carbotech xp10/8s for my last 2 events of the year. The rotors do not have any cracks at all... do I need to change the rotors out? I am concerned about new rotors/new pads combo.

At what point do rotors become a too thin to use? Is the lip any reason for concern?

Thanks,

cj

Aardwolf

I use a micrometer to measure and check, the min wear thickness is sometimes on the back of the rotor. If it is a NAPA rotor they have the min thickness on the site as well.

wallyman424

i've yet to see someone that tracks a c5 run out of rotor material before they crack.

Bill Dearborn

With stock pads that can happen as they do not heat the rotor to the high temps seen with racing pads.

Bill

cj68

Do you think I am running a risk with the rotors that I have now? They have? I have only went through 2 sets of pads on the front and have about 18,000 miles on the rotors.


Thanks Wally... that's kind of what I figured. I think I am going to run my existing rotors with the new Carbotechs for the next NASA and FWash events, unless someone suggests that I am in "unsafe" territory. The problem is that I will not have enough time before the event to break in new rotors along with new pads.

See you at NASA.

cj

jpobrien

I just switched to Carbotech, and they recommend using new rotors or turn the old ones if they were not already being used with Carbotech pads. Something about the pad material getting into the microscopic cracks in the rotor.

UstaB-GS549

I have never worn out a rotor yet, but then again mine don't get many street miles.

Check your rotors for cracks every time you come in to pits. I have never had a rotor crack while on track. It seems to only happen while cooling after getting off.

Never ignore brake vibration. Even if it is subtle or seems to go away as the brakes warm up. A small crack in the rears will be pretty hard to feel thru the brake pedal. front cracks are pretty obvious. You have to look hard sometimes. It's difficult to spot if it is behind the caliper.

Bring spares. Even if they are junky "limp home" types. In a pinch you can drive home with a cracked rotor. I have done it a few times. You get good about no using brakes and looking wayyyyyyy ahead in traffic for slowdowns.

New, old, it doesn't make any difference. This one was new and was on track for two 20 minute sessions at Road America in cool weather. Others have lasted a few seasons for now apparent reason. The crack is always in the outer surface.

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gkmccready

Ever wonder if that's because we all put brake ducts blasting on the inner surface and it leads to uneven heat distribution?

ErnieN85

Partially but lot has to do with the rotor being one piece and the hat firmly attached. because of that it can't expand and contract evenly. with two piece rotors the attachment point floats with some brands and allows the disc to not flex into a cone shape

John Shiels

spindlle duct pump it into the center so you get better cooling on both sides.

WNeal

Wow

I check mine constantly and always have a new set with me but have not seen a crack like that before.

thanks for the info

RUN4CVR

I've heard that you should avoid pulling the parking brake after you get off the hot laps...something about putting a cool pad on a hot rotor = crack

SouthernSon

If one will not use the brakes coming off the track and simply downshift to slow for the paddock and, when stopping, kill the motor and let out on the clutch to stop the rotors should last longer than using the brakes in the paddock. That said, I have still cracked several rotors this year; front and back. It will happen but just not as often if you try to let the rotors roll free upon stopping. Of course, a practice/real red flag has gotten me several times. One can sometimes hear the "Ping!!" as the metal lets go.....

UstaB-GS549

Here are a few more:

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Z06 Bob

I cracked a front rotor this year on the track at Pocono.
Not a great feel at 145mph.
Luckily I had a brand new set to go on.