24Chromium

Anyone here ever warp the rotors (steels) on your GT3? I thought I had a warped rotor when swapping in new pads. Now, I've warped rotors in the past. And that was quite an ugly experience. The car shook pretty violently. This time I had no vibration. Just a little bit of steering wheel shake (very minor) under hard braking. The rotors I'm using are Giro Disc (2pc).

I decided to take Violet to a shop that has a brake lathe to machine them back to true. They suggested I at least have them all sanded (refaced) since I had changed compounds. I agreed and in turn asked them to check all 4 for true. I'm glad I did. All four were out of tolerance for warpage. They skimmed them true, refaced them, and now I'm good to go for this weekend.

I asked about how I might be warping them, since I honestly didn't think I was doing anything that would cause such problems. I was told that since I'm mainly tracking the car, they just get over heated and start to curl from the repeated abuse. I was also told I'm probably over-braking (true that!) and not giving them enough cool down (also guilty).

996FLT6

Poor braking ie only brake when u need to. U still riding brakes but much less now. Mike

mooty

i only ran oem rotors (in the past) or used the super heavy cayenne rotor derivitives on 6gt3. never warped anything. i dont bed pads, i dont belienve in cool down laps. my rotors smoke BIG time when i roll to my parking spot. never warped anything. and believe me, you brake WAY less than i do.

but your stuff fail in strange way. even mooty cannot duplicate it.

996FLT6

Have u ridem with him? I have : ). Mike

mooty

he brakes more than i do?
damn, he's the new mooty or what?
does his car push too?

drl

Long time ago someone else posted here about warped girodisc rotors - something about rotors being basically new and were not being replaced by manufacturer

24Chromium

I'll put money on this... _your_ rotors are warped too. You just don't notice it. I didn't. I would have been happy as a clam tracking the car this weekend if I hadn't had them trued. I might have had a little more steering wheel shake, but I would just chalk that up to the wheels getting out of balance, from the tire spinning on the wheel during hard braking.

mooty

you can have the shop measure the rotors i took off.
probaby is, and car shakes. i just ignore it.

911rox

I recall the same post drl...

Warping is mainly due to materials used, heat and use... Just bed them in again now that they have been machined 24Cr to minimise chances or further warp although as they get thinner they tend to warp faster.

Had it happen many times on street cars (remedied with better rotors), not on the 3 yet but running PFC...

M3EvoBR

Disc quality and temperature.
Everybody cares if they see their engine gauge on red, nobody cares if they brakes are working on less than optimal temps...
With OEM never happened.
With PFC never happened.

TRAKCAR

^^ Same here..

paver

Race Technologies(the US distributor for Brembo) told me that is virtually impossible to warp their type lll disc. Is that BS? After reading Lar's first post I'm not sure I believe them. I have some on that shake the wheel a little when I brake. I guess it would be due to uneven pad deposit though because it's not there every time. Mostly at street speeds.

edwin814

I had Brembo type III rotors on my old supercharged E46 M3. Never had steering wheel shakes on the track.

Wilwood rotors on my E30 M3, on the other hand,

P.J.S.

Brembo Type III -- never an issue for me -- 2 sets with another set in route... some wobble once in a while but it is intermittent, which is not warped rotors
they are not cheap, but not BS either - and I certainly am not burning half a day and a few bucks getting them removed, turned, resurfaced, and re installed

Space Coast GT3

Drl: think you were referring to my post, think it was about last year at this time. I converted my PCCB to GiroDisks. About 600 or 900 miles and no track days the steering wheel shook big time on braking. Craig at RennStore was helpful and contacted RSS who offered to turn them if I shipped them back. However a local shop turned them for 80 bucks and that was cheaper than the shipping. They have been fine ever since. I do not know, but I have suspected they warped as I bed in new pads on new rotors. Maybe I did not softly warm the rotors through a cycle before bedding pads. I do take extra care to make sure I cool down well before parking.