Bad vibration after track day

[MinionM3]

Hello all,

I recently took my car to the track for the first time - I have a '95 M3 Track car and have been driving on track for a while, but decided i wanted to test out the E92 for a change and see how it stacks up.

I swapped my wheels for the track session and put my "Daily" wheels back on afterwards.

Now, I notice a pretty bad vibration under moderate to hard braking and even sometimes i get shaking in the steering wheel occasionally, almost as if the wheels are not balanced properly. I would think tire balancing, but the car drove perfectly before the track and i didn't run these wheels at the track, so no reason to assume the wheels magically came unbalanced from taking them off and then putting them back on; also the shaking while driving is random - its not consistently at "X" speed or above.

I am thinking it COULD be rotors warped, but, my brakes have less than 20K miles on them (Rotors and Pads) and i know what i am doing at the track so i dont sit on the brakes after an out session, i dont put the e-brake on, i take a full cool down lap, etc...

I dont want to dump a ton of $$$$ into new brakes for that not to be the problem - especially considering my rotors and pads are very new.

Any thoughts/ideas? Anyone ever have something similar?

I suppose it could be suspension bushings wearing - it just weird that it was perfectly fine, no issues whatsoever before the track and now it feels like its going to vibrate apart after the track :-(

[roastbeef]

you can be pretty gentle on the brakes after a session and still get pad deposits. i hate to say it, but i think your front brakes are jacked... hopefully its just pad deposits.
what tires did you swap on? my first day on oem brakes after getting a set of track wheels with nt01's i fried my oem brakes. of course, this was a lot earlier in my hpde career, so i was probably on the brakes too much, but the moral of the story is that sticky tires with oem brakes = F'ed brakes.

[MinionM3]

Originally Posted by roastbeef

you can be pretty gentle on the brakes after a session and still get pad deposits. i hate to say it, but i think your front brakes are jacked... hopefully its just pad deposits.
what tires did you swap on? my first day on oem brakes after getting a set of track wheels with nt01's i fried my oem brakes. of course, this was a lot earlier in my hpde career, so i was probably on the brakes too much, but the moral of the story is that sticky tires with oem brakes = F'ed brakes.

Yea - I'm afraid of that too - especially since I was in stock Pads...

The tires weren't anything special - just the OEM Michelin PSS's

It was a streets of willow tho, so super tight and lots of heavy braking zones

Anyway to correct brake deposits or just have to scrap the front rotors/pads and call t a day?

[roastbeef]

i've only been there once, but i don't remember streets being a brake eater. pss's aren't super grippy, either.

people often cite an abrasive brush device that they put into a drill and use it on the face of the rotor.... i have never done it and wouldn't. i'd be worried that i wouldn't do an "even" enough job and screw it up even more.

[Estoril Blue]

The usual first easy answer is "pad imprints". Have you pulled wheels and had a good look at the rotor faces?

Which pads?

I'd drive it for a week or more before I started changing things. Maybe go through a bedding procedure and see if that helps.

[MinionM3]

Originally Posted by Estoril Blue

The usual first easy answer is "pad imprints". Have you pulled wheels and had a good look at the rotor faces?

Which pads?

I'd drive it for a week or more before I started changing things. Maybe go through a bedding procedure and see if that helps.

I have taken wheels off to look - nothing that I can see or feel on the face of the rotor.

This was about a month ago - have driven the car daily since and taken it on one hard run to see if hard braking again would cause everything to smooth out - it got slightly better, but still there.

OEM rotors and OEM pads

[1MOREMOD]

Pad deposits, more aggressive ones for a session will cure it

[MinionM3]

Originally Posted by 1MOREMOD

Pad deposits, more aggressive ones for a session will cure it

Any suggestions on pads for this?

I daily the car and take it to the canyons every other weekend or so....

[1MOREMOD]

For an intermediate pad could try ferodo ds2500s, or stop tech sr34. I've used both on street. They will squeal some on you though. Also used paid rs19 but they are tricky to bed.

[Rassilon]

It's definitely pad deposit. My steering wheel shakes like a vibrator every time I brake hard after a few laps on track with stock pads. For me, it usually goes away after a lot of street driving though.

[MSteve5036]

I would also bet pad deposits...long shot bet on accidentally knocking off a wheel weight when you swapped wheels

[doogee]

Yep, pad deposits. OEM pads are bad for this.

Either get some track pads to clean the rotor, or try one of these:

https://www.amazon.com/Performance-T...rds=rotor+hone

[ailikesiliu]

pad deposits, a couple weeks of daily driving should cure the problem.

[dparm]

Don't use street pads at the track, period.

[bigjae1976]

Did you check the back of the rotor?

Warm the brakes up (NOT HOT)...spray with water and let the rotors rust up over night. Do one hard stop and your problem should be fixed. You have to spray the backside of the rotor as well.