MaddMatt

Recap: Used Panther + and R4 pads last year. Never warped a rotor on track. Use cheap-*** pads (go here: https://honda-tech.com/zerothread?id=132398) one time on track and warp the rotors to hell.

New: Used Jon Felton's (thanks again Jon) R4 pads and V700s this past weekend at VIR in exchange for him being able to drive my car a few times that weekend.
So there were 2 drivers, much harder driving and less cool-down time since the checker was thrown at Oak Tree instead of start/finish. Result: not a hint of warping. None.

Same track. Same driver. Same temperature (within a few degrees). Same rotors (just had them turned, so if anything they should warp easier since there's less metal now). Much harder driving. Less cool off time. No warping.

I have to conclude that the cheap pads are causing the rotors to warp. I just don't know how or why. It doesn't make sense. Anyone care to make a stab at it? Where's Andie?


[Modified by MaddMatt, 3:16 PM 2/28/2002]

cvcc130

Matt, I used to have that problem with the civic. I had metal masters on the car at the Glen and by the end of the weekend at the braking zone for one, the whole front end was shaking horribly under braking. What it was was crappy pads depositing pad material on the rotors. Not the rotors warping. I went through two sets of rotors before I figured out what it was. Solution... Hawk Blues. Yes, they do eat the rotors up a bit more than other pads but they have never ever warped a rotor.

4doorH22

What are the symptoms of the warpage? Is the wheel vibrating with even light braking?

MaddMatt

At slower speeds, it's not noticable. At highway speeds and above, the front end vibrates like a drug dealers pager in a crack house.

I briefly entertained the idea that the more aggressive pad was actually shaving the rotors ever-so-slightly and keeping them from warping. But if it's just a transfer layer thing, it should go away with time, right? I took the rotors to O-man to get turned, I suppose he could tell me if they were really warped. He wasn't at the shop when I picked them up.

Willard

transfer thing can be removed with sand paper.. so with time they should true up.

did you use a "dial-indicator" on them to measure the run-out?

Will

whitney

I don't know if this has been posted here before, but... It's titled "THE WARPED BRAKE DISC AND OTHER MYTHS OF THE BRAKING SYSTEM" by Carroll Smith.

So-called "warped" brakes are caused by non-uniform pad material transfer to the rotor. Considering the complex cycle of brake material transfer that occurs as is explained in the article, it's no surprise that the extent of "warping" is highly sensitive to pad material being used.

Highly recommended reading.
http://stoptech.com/whitepapers/warped_rotors_myth.htm

whitney

Carroll explains exactly why "warped" brakes due to uneven pad transfer will get worse over time. Short explanantion = the "high spot" heats up more and more iron transforms into cementitie (Fe3C). Cementite is "very hard, very abrasive and is a poor heat sink. If severe use continues the system will enter a self-defeating spiral - the amount of cementite increases with increasing temperature and so does the brake roughness."

I knew my Materials Science degree(s!) would eventually pay off

siisgood00

Everyone really needs to read this. Its quite lengthy but has some amazing information.