4SELLL

Ive got two cars with z06 brakes. One i have run at the drag strip (15 passes) and a mile track (two passes) and street use, the other i drive on the street only. Any way ive had the rotors warped on both of them multiple times in 4 mos. Ive turned the rotors on both twice and they are warped again. Miles on the rotors are in the 20k miles range both cars. Is this common? Im thinking i need to replace the rotors but dont want to do this all the time. What rotor replacement are people using.. i dont do any sports car racing at all.

Stingray23

stock rotors suck. Get the Coleman 2 piece.

AzDave47

Turning the rotors twice means they are probably below the minimum thickness and that makes them more susceptible to warping.

I've done 5 HPDE days (experienced racer) with stock pads and rotors and 4 1 mile passes. I don't have any warping but now have micro-cracks forming at the drilled holes. It would not seem that you should be having the rotor warping problem with how you've driven. I will be going to two-piece Coleman rotors before my next HPDE. but that should be more than you need.

Mine is an 09.

RichieRichZ06

What he said.

Also, what type of vehicles are the brakes on? A 4,500 pound truck trying to use the C6Z brakes to stop is much different then a Miata that is using C6Z brakes.

4SELLL

Sorry one is a 07 z06 and the other is a 07 C6 Vert. It seems the colemans are alot of money, any other alternative?

Dale1990

Out of curiosity, how much run out are you seeing on the rotors and how thick are they after being machined twice?

DrtyHarry

DBA makes a fine product, but they are also expensive.




Harry

BEZ06

I suspect that you actually are getting uneven buildups of pad material - not warped rotors.

Read this StopTech document:

The "Warped" Brake Disc and Other Myths of the Braking System


Scroll down to the part about "pad imprinting" and you'll see a link to "Figure 5", and this is the picture of pad material deposited on the rotor:




I think that's probably the cause of your "warped" rotor!!

Bob

Zo3o6

RichieRichZ06

Good info to look at.

BEZ06

Yes - the StopTech White Papers have a wealth of information!!!

Here's a link to the White Paper index page:

http://www.stoptech.com/tech_info/te...e_papers.shtml


The articles have lots of brake info to answer all kinds of brake questions - pad knockback, how to bleed brakes, brake fluid, stainless steel brake lines, etc.


Here's another site with some very good info about brakes - especially about "burnishing" them:

http://www.essexparts.com/profession...urnishing.html

Click on the "Learn" tab to see more info.


Bob

okiedude

Dang, you beat me to it. Don't know how many times I've had to share the "white pages", it is a wealth of information.

Gary2KC5

I don't have much experience with drag racing stock cars...I do road racing track events...so over the last 10 years I have been through about 1000 lbs. of rotors...I've never had any lateral run out. except on my wifes C4 that spent most of its life sitting in the garage.

What we end up with as rotor failure is cracked rotors (cracks big enough to put a credit card through)

cooling them off after coming off the track is huge in keeping them alive. I'm not sure what stress drag racing puts on rotors...road racing generates 160 mph to 45 mph, 160 to 70, 110 to 45, 145 to 70 stops on rotors each lap for 10 laps, 4 sessions a day sat/sun.

this distroys rotors but does not cause wrapping. good rotors can take severals weekend events before needing to be replaced

BEZ06

with Gary2KC5!!

I also run track events on road courses, and I've been through a bunch of rotors - but they crack, not warp:




The rotor above is one of my DBA 4000 rotors - it's a single piece, and one of the front rotors. During the cool down lap at the end of a session I try to stay off the brakes as much as possible. After parking, I never set the parking brake, and I keep my foot off the brake pedal to avoid pad imprinting. I try to roll the car either forward or back a foot or so every couple of minutes for the first 10 minutes after parking in the paddock to keep the hot caliper/pads from focusing heat on one section of the rotor.

Butt.....you just can't keep cracks from occurring forever!!!

Whenever you have heated up the brakes, whether spirited street driving, or especially after a track session - don't leave your foot on the brake pedal when you come to a stop. You risk pad imprinting which results in the uneven deposit of pad material, and that will cause a pulsation of the pedal during subsequent stops that can be misinterpreted as a "warped" rotor.

Bob

SpartanSupps

okay guys, need to bring this thread to life again..

I just installed coleman 2piece and they warped right away.
I was getting a pulsation in my seat which from what I read indicates the
rear are warped. Had them turn and sure enough one spot was warp?
No idea really what to make of this, they still pulsed after i re-installed them.

Doing some research, a lot of guys had this issue with coleman and said they suck.
Now what is true I dont know but I am upset with my poor "pre" research and am ready
just to go back to the cheap factory rotors....

I don't even track the car, just daily drive with some spirit

AzDave47

Usually the rotors don't warp, the pulsing is from uneven pad buildup on the rotor.

Take the car out and do five hard (not quite into ABS) 60-20 stops , then five 80-20 stops and then drive for about 10 minutes to evenly cool off the brakes. That may cure the "warping" and it also gets rid of brake squeal.

SpartanSupps

I will attempt this today. I have read the stop tech article. So lets see if it is just improper buildup.

Thank you!

63Corvette

Bingo!!!!

carpe dm

I had material deposits and took the easy way out with DBA rotors. NO problems since.

v8sten

I personally have no issues with the stock GM rotors, I daily mine and push it real hard on the weekends on the highway. I've had the stock rotors glowing enough to to light up the side barrier on the highway multiple times. Jamming on them form 160ish to 60ish mph. I'm on a complete stock brake system. Also an 07 Z06. The only time I felt a little warpage, I got up to speed and road the brake a little bit and heald it, they straightened right up. Mine have cracks around each hole, I do not see any reason to turn a cross drilled rotor. They are cheap enough from the dealership to replace them, why not.