in preparation of a track day at NJMP, i installed brand new, fresh out of the box brembo blanks, and hawk HP+ with one track day on them. after a quick pad bed in, i loaded the trailer and went down. at the FIRST time on the track, with the FIRST press of the pedal over 50mph with only moderate pressure, i got a shudder like you wouldnt believe in the front end. it shook the wheel so bad, i had to keep a death grip on it just to maintain control. i think warped rotor....but on BRAND NEW brembo blanks?? they had absolutely NO miles or heat in them whatsoever.

so after emailing tirerack, where i bought them, the answer i get was 'you overheated them at the track, they were too hot, and the pad probably had material buildup on it'. yeah, right...

they also said 'these rotors are not recomended for track use, you should use a slotted rotor'....again, yeah right.

after calling a customer service rep at tirerack, she said the same thing -overheated rotor. yet wouldnt listen to me when i said i had the shake at the very FIRST press of the pedal. she also said using them on the track voided any warrenty brembo had. like im the only one who has ever used brembo blanks for track use??

has anyone else had a bad set of brembos right out of the box? has anyone else delt with warrenty replacement or defects with them?

 

never heard of that, but I did hear someone bedding there brakes then washing the car which warped the rotors. Never ever mention racetrack when dealing with customer service

 

I have the same exact blanks with hp+ and simliar happened. With street tires there were fine but R rubber was too much.
I either warped them pretty early or got abs shutter. Im going to try some ATE rotors and if that doesnt work try resetting the abs.

 

Are you 100% SURE it's the rotors?? Have you checked all 4 wheels for missing wheel weights? If you're running track wheels/tires, have you checked to make sure they're clean of all rubber build-up? (big chunks, esp.).

I drove with 4 completely f'd up wheels/tires, and yeah, it's downright scary! I almost have a hard time believing that the rotors would cause such a violent shudder, esp. after initial install, with little to no use?! Even if they're warped, theoretically, it still shouldn't put them that far out of BALANCE.

 

i also have an ongoing sister thread to this in the susp. and brake forum.

if there was a missing weight, shouldnt it happen all the time, and not just under braking? the tires are falken 615s, not r-comps. there was no rubber buildup, and even if there was, it would have been scrubbed off after the first hard lap.

i also had a very low, soft pedal with this setup.

a few weeks earlier, i had a track day with the same pads, tires, but different rotors. i had a perfect pedal, and no shake at all. the only variable left is rotor.

after i got back, i put my street tires, pads and rotors on, and everything was fixed. high, firm pedal, and no shake whatsoever.

 

Maybe they are referring to buildup on the brake pads, from being run on a different set of rotors? Are the brembo blanks the same thickness as the stock C5 factory part (maybe they shipped you rear rotors by mistake)?
Fronts are 12.8" x 1.26" +/- Rears are 12.0" x 1.02" +/-. I'm not even sure that makes sense, but anything is possible.

I run the same pads on the factory C5 rotors and have never had a problem like you describe (I always run new pads on new rotors). Assuming the rotor is the correct part # and a dimensional equivalent, there is a problem with the pads and the rotors. I'm guessing used pads and the new rotors aren't liking each other. No doubt you bedded them in, but something on the pads must be preventing good material transfer from the pad to the rotor. Did the situation get any better as you got heat into them? Are the pads glazed? Did the new rotors come with a rust preventative coating on them? If so, did you use brakeleen to wipe down the new rotors? If not, then the used pads could have been contaminated with the rust preventative coating and rendering them useless. That could explain the exessive pedal travel, pressure and heat?? Just thinking out loud

Either way I think at this point I'd start with new pads and new rotors.
Chalk this one up to experience.