Braking vibration on the track

MattRC51

New member
Hi guys,

I started another thread as I'm looking for new rotors but it turns out I'm skeptical of the problem now... Looking for your input!

I recently put Hawk street-race pads on my M3 and got my (front) rotors turned. Problem is that once the brakes are hot on the track, when I brake at higher speeds there is a lot of vibration in the front.

I made sure to properly beddin the brakes (learned that the hard way...) and started fresh after with the ''new'' rotors. But why am I still having this vibration? It does not happen when the setup is cold or on the street.

Mi idea was to start fresh with new rotors at least to eliminate this from the equation. Hence me looking for Stop Tech discs, or something slotted at the very least.
 
Why do you want slotted rotors ?

Slots are meant to prevent gas buildup between the rotor and the pads when pad material is outgassing ... They are not cooling your rotors



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Why do you want slotted rotors ?

Slots are meant to prevent gas buildup between the rotor and the pads when pad material is outgassing ... They are not cooling your rotors

Sent from my Nexus 7 using Tapatalk

Yup that is my understanding as well. From all the research I've done its the way to go.
 
Not sure I understand....You have put new rotors or you want to put new rotor? If you only change the pads, sometimes the old pads have built up dust that stick on the rotor... It takes time to get rid off and makes anoying vibration lime you get... But it shouldn t last long... Couples sessions sometimes...
 
If you turned your discs, the problem can be there.
Most likely the carbon transfer is uneven right now. If you swap out pads and daily etc, you can have transfer issues,

and it would help to know what generation of M3.
 
if you turned your discs, the problem can be there.
Most likely the carbon transfer is uneven right now. If you swap out pads and daily etc, you can have transfer issues,

and it would help to know what generation of m3.

e46 m3
 
Its a toss up between warped discs- never ever turn discs that see track use- the heat sink characteristic will diminish and carbon transfer to the disc.
seeing as you are using semi track pads- I will bet on disc warpage.

solution-
Stoptech blanks or slotted, new discs- and re install the Street Race pads- you should be good.
No special breakin treatment required.

If you decide to do a lot of track- consider PFC 08 compound pads and be done with brake issues.
 
If you turned your discs, the problem can be there.
Most likely the carbon transfer is uneven right now. If you swap out pads and daily etc, you can have transfer issues,

and it would help to know what generation of M3.

Thats what I was trying to explain with too much words l:D
 
Its a toss up between warped discs- never ever turn discs that see track use- the heat sink characteristic will diminish and carbon transfer to the disc.
seeing as you are using semi track pads- I will bet on disc warpage.

solution-
Stoptech blanks or slotted, new discs- and re install the Street Race pads- you should be good.
No special breakin treatment required.

If you decide to do a lot of track- consider PFC 08 compound pads and be done with brake issues.

I have the slotted Stoptech rotors with Pottefield RS-4, a similar setup to the OP that I had installed just before winter (did not bed the pads). Use the car as a DD only and I’m having the same problem.
 
I have centric rotors, slotted, with Hawks HP+ pads. I do some lapping and I have the same problem here.

Pretty sure it's not warped (i've experienced it before and it's different), but there is a kind a jitter/vibration when braking.
Close to the slots, there is some kind of black deposit that won't come off, I suspect it's the reason the vibration.

The rotors are good to throw away if I can't turn them for track use?
 
In most of the cases of brake judder- its the inconsistent layer of carbon transfer to the rotor. This can be alleviated in several ways- dedicated pad/rotor set that see track use only- transfer layer stays intact OR drive through the judder on the track until layer evens out.

Some pads lend more easily to a nice transfer layer than others. Slotted rotors clean pads efficiently but lend to more transfer layer issues.

There is really no perfect way to handle it when a car sees track duty and street duty.

That being said- the OP's issue is surely warped rotor as he turned them. This is a no-no for track use.
for the rest , try driving hard through the judder to see if it stabilizes, then dedicate kit to track use only.

FWIW, most all of my clients running BMWs and Porsches use PFC 08 pads with no real issues. This pad really kicks ass, but it is expensive- but lasts twice as long as its competition.
 
I double-duty Hawk Street-Race with cheap Centric plains (15$) and no issues. Granted my car is slow :D
 
Je sais pas ce que vous en pensez mais j'ai entendu que de torquer les roues overtorque pourrait causer un disk warp

en serrant les roues trop fort, on écrase le chapeau du disque, quand le disque se met à chauffer, avec l'écrasement il se dilate plus aux points de serrage

en ayant un chapeau de disque trop écrasé et avec la déformation, ca fait crochir le disque

Une raison parmis tant d'autres de ne pas trop torquer les roues
 
Je sais pas ce que vous en pensez mais j'ai entendu que de torquer les roues overtorque pourrait causer un disk warp

en serrant les roues trop fort, on écrase le chapeau du disque, quand le disque se met à chauffer, avec l'écrasement il se dilate plus aux points de serrage

en ayant un chapeau de disque trop écrasé et avec la déformation, ca fait crochir le disque

Une raison parmis tant d'autres de ne pas trop torquer les roues
Hmmm, possible. Surtout si c'est pas torqué égal.
 
People still have rotors turned?
They overheated once, and now they are thinner, get the picture?
Buy new rotors.
I do get a small occasional vibration during the first couple sessions after street use from uneven deposit. But it goes away after a few sessions.


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