Have any of you guys warped the stock rotors?

4165 Views 24 Replies 10 Participants Last post by Vapiano, Sep 22, 2012

boarderag

Discussion Starter · Aug 24, 2011

I went to the track last week with my new brake setup (MX72 pads, stainless lines, AP 608 fluid) and it performed great. Only issue is that ever since the track day, I'm getting some shuddering during high speed braking, like coming off an off-ramp. I can't tell if the pads just wore unevenly, or if the rotors are warped. Anyone else have any experience with this happening? I didn't think the rotors could warp this easily....

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doborder

· #2 · Aug 24, 2011

Funny thing is I have the exact opposite thing happen.
I took my car to the track after getting new AP J hooks, ME20's and SS lines place and the brakes shudder during hard braking... I found out later that the ME 20 needed to be bedded. After that, no more shudder. I just returned to the track after about 4 months. I was expecting the same thing, but the brakes worked great. I didn't bed them again after the initial bedding process.
This maybe the same thing. You may need to bed the MX72? Although I don't recall doing that on my last set?

boarderag said:
I went to the track last week with my new brake setup (MX72 pads, stainless lines, AP 608 fluid) and it performed great. Only issue is that ever since the track day, I'm getting some shuddering during high speed braking, like coming off an off-ramp. I can't tell if the pads just wore unevenly, or if the rotors are warped. Anyone else have any experience with this happening? I didn't think the rotors could warp this easily....

icarus

· #3 · Aug 24, 2011

boarderag said:
I went to the track last week with my new brake setup (MX72 pads, stainless lines, AP 608 fluid) and it performed great. Only issue is that ever since the track day, I'm getting some shuddering during high speed braking, like coming off an off-ramp. I can't tell if the pads just wore unevenly, or if the rotors are warped. Anyone else have any experience with this happening? I didn't think the rotors could warp this easily....

I remember looking at your rotors at the NW drive, they had a few cracks appearing, and with 30k miles on them and some track time I would not be surprised if they are warped. Pacific Raceways looks like some long straights followed by some tight turns... a recipie for hot brakes. I warped my brand new front J-hooks after only about 10 track days. Had them machined (turned) and they were good as new, have 16 total track days on them now. I expect them to last about 20 days total. The rears pads/rotors look like they'll last 3-4 times as long as the fronts.

Some advice to maximize rotor life & costs:
1) Switch to AP Racing rotors, about 1/2 the cost of OEM
2) Use a full race pad (Carbotech, Carbon Lorraine, Performance Friction, etc.) and bed them properly to the rotors
3) Don't use a full race pad on the street for long periods of time
4) Avoid using non-compatible pad compounds if switching between street and track pads between track days (Carbotech 1521 street / XP12 for example)
5) Change pads as soon as they get to 40% remaining. Pads lower than that don't dissipate much heat
6) Do a full, proper cool down lap at the end of every session, where you don't ever touch the brake pedal
7) Don't drive through any water after a track session
8) Don't put your parking brake on after a track session
9) Add brake air guides, ducting, and/or water misting cooling solutions

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pi-man

· #4 · Aug 24, 2011

I'd have to see them but it may just be the way the pad deposits are left on the rotor. I had this problem with one of my earlier sets of rotors where the pad bedding layer wasn't even and it felt like it was warped. Just something to check.

seanm

· #5 · Aug 24, 2011

How did you bed in the new pads? Did you park with the brakes really hot?

To me sounds like it might just be some pad deposits.

boarderag

Discussion Starter · #6 · Aug 24, 2011

I bedded the pads per the Endless instructions. I drove them on the street for a few weeks prior to the track day, and did some hard braking during some spirited driving and they were perfect.

I did a proper cool down lap at the end of each session, and I did not engage the parking brake while the brakes were hot. My initial guess was like Sean said, probably excess pad deposits, but I don't know how to tell. If it is just pad deposits, how long would it typically take to wear back down to a normal transfer layer thickness during street driving?

@Icarus: I was planning on switching to AP rotors once the stock ones are done, but I think they still have a few track days left in them.

seanm

· #7 · Aug 24, 2011 (Edited by Moderator)

boarderag said:
If it is just pad deposits, how long would it typically take to wear back down to a normal transfer layer thickness during street driving?

Throw some Hawk Blues in there, and the deposits will be gone in no time.

aboodilatif

· #8 · Aug 31, 2011

boarderag said:
I went to the track last week with my new brake setup (MX72 pads, stainless lines, AP 608 fluid) and it performed great. Only issue is that ever since the track day, I'm getting some shuddering during high speed braking, like coming off an off-ramp. I can't tell if the pads just wore unevenly, or if the rotors are warped. Anyone else have any experience with this happening? I didn't think the rotors could warp this easily....

I have the same problem with my 2012, with 7200 miles on them and zero track days. I really want to know if its the disc that's warped and needs replacing or is it the pad transfer

seanm

· #9 · Aug 31, 2011

aboodilatif said:
I have the same problem with my 2012, with 7200 miles on them and zero track days. I really want to know if its the disc that's warped and needs replacing or is it the pad transfer

What brake pads are you running?

aboodilatif

· #10 · Aug 31, 2011

stock

seanm

· #11 · Aug 31, 2011

aboodilatif said:
I have the same problem with my 2012, with 7200 miles on them and zero track days. I really want to know if its the disc that's warped and needs replacing or is it the pad transfer

If they are stock, then honestly its something you need to tell us, because you have the car in front of you. You should be able to look at the rotor, and see if there is anything that looks "funny".

Modern rotors really don't warp much. More often its deposits.

aboodilatif

· #12 · Aug 31, 2011

if I had it infront of me I would be able to tell you, sadly its in a container being shipped over from the states. It a thing that I was worried about that appeared on the last week of me driving it before shipping it. but ill let you know as soon as it arrives in a couple of days

seanm

· #13 · Aug 31, 2011

aboodilatif said:
if I had it infront of me I would be able to tell you, sadly its in a container being shipped over from the states. It a thing that I was worried about that appeared on the last week of me driving it before shipping it. but ill let you know as soon as it arrives in a couple of days

Did you drive the car hard? Do a few high speed stops? I know you said 7200 miles and no track days.

aboodilatif

· #14 · Aug 31, 2011 (Edited by Moderator)

well the only time I recall using the brakes hard was when I did a top speed run and I hit the brakes hard at 180+ , that was about the only time I hit hard on the brakes. could that cause warping of the rotor?

and I dont drive really hard on the car.. my driving is what some might call "spirited"

seanm

· #15 · Aug 31, 2011

aboodilatif said:
well the only time I recall using the brakes hard was when I did a top speed run and I hit the brakes hard at 180+ , that was about the only time I hit hard on the brakes. could that cause warping of the rotor?nd I dont drive really hard on the car.. my driving is what some might call "spirited"

I don't think you could have warped a rotor. I would be looking into other things, checking the pad surface. Wheel weights/balance. Double check the alignment. Double check for anything loose in the suspension.

aboodilatif

· #16 · Sep 1, 2011

the alignment and wheel weights are spot on, i still think it is the pads that have worn out unevenly rather than the rotor warping.

Radguy

· #17 · Sep 4, 2011

[email protected] said:
Throw some Hawk Blues in there, and the deposits will be gone in no time.

Boy, that's for sure. Those are like a portable brake lathe!!

I had some pad deposit on my front Brembo discs from a set of Ferodo DS 3000 pads when running my Z06 at the track--Could not for the life of me get rid of it even after using a set of Porterfield R4's as "cleaner pads". One session with the Hawk Blues--clean as a whistle!

Oh, and by the way, I was also initially convinced that I had warped my rotors--but the Brembo rep explained that it's almost impossible to warp a set of 2-piece floating rotors. Judder is almost always from pad deposit.

Jonathan

Vapiano

· #18 · Sep 4, 2012 (Edited by Moderator)

Bringing this thread back from the dead, I have the same exact set up as OP and experienced the same shudder today from a high speed stop. My wife was actually driving and I felt and heard the shudder! WTF!? The steering wheel does not shake and the brake pedal doesn't pulsate at all. I stopped to check all the lugs, they were all tight, I checked the brakes pad to make sure no pins were missing, good to go here and the alignments is fine. I hopped in the drivers seat took her out for a spin and did a high speed stop and experienced the same thing. I followed the Endless bedding procedure verbatim! Pads have about 50 miles on them.

Is purchasing a set of Hawk Blue pads the only way get the bedding deposit off the rotor? I have posted pics of the front rotor for evaluation, does anything look out of place?

Edit: these are the original rotors with 5K miles on them.

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2

Vapiano

· #19 · Sep 5, 2012

Bump, anybody?

shawnhayes

· #20 · Sep 5, 2012 (Edited by Moderator)

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