Just curious to see if anyone else has done this.

I took my 2011 M3 Convertible to the track the other day to see what it could do. I did pretty well enough but I seem to have warped my brake rotors.

The car is on the heavy side with the extra 550lbs that the drop top adds but it was still fun on the track. Not as quick as the 2006 Porsche 911s that it replaced but almost as much fun to drive. The track was MSR Cresson 1.7 CW- medium hard on brakes as far as tracks go.

It developed a shimmy under braking only toward the end of a longer session. This has persisted after the car cooled and as far as I can tell this can only be warped brake rotors.

Is this a common occurrence on an M3? Is there a different rotor or pad I could use to keep this from happening again?

I have been doing track days about 6 events a year for the last 5 years so I have some experience and didn't do anything as stupid as standing on the brakes after a session.

As far as I can tell the car does not automatically apply the brakes when the car is placed in park so it must have simply gotten too hot and had too much force applied to it when hot.

There was no significant fade to warn me that I was about to cook the brakes.

It would be disappointing to not be able to track the car for fear of having to replace rotors each time.

Any suggestions would be appreciated before I change out the rotors.

Many thanks

 

If you were on stock brake pads I'd bet that you have excess pad deposition on the rotors. As a first step I'd try cleaning the rotors before installing new ones.
Bish

 

That would put a huge smile on my face! Will try that. Thx

 

If you used stock pads, it's most likely pad deposits. If you can't scrape it off, see if you can get a hold of some track pads. They'll scrape the deposits off if you drive around on them cold.

 

if you plan to track it more, i would upgrade to a big brake setup.

if cleaning doesn't help, you can have the rotors turned or just get new ones.

 

Just a follow up. The problem slowly resolved so- it was just uneven brake deposits. Many thanks!

A

 

Big brake kits are definitely the way to go. I have Stoptech. Probably the best purchase I've ever made. (aside from my car, or house, or a couple other things... )

 

Thanks for the reply, Mike. That is a pretty strong endorsement there!

I gotta say that I am more than a little disappointed that BMW would build a track car with brakes that are not good enough for the track.

I am heading to Texas World Speedway this weekend with better brake pads. I hope that will help. TWS is faster and not as hard on brakes as MSR so it should be fine.

I'm also there to test drive a 996 spec car. I think I will just quit screwing around with a dual purpose car and go all in.

 

Doc Texas Speedway sounds awesome and I'm jealous. I have to agree with you about BMW. Dual purpose cars are great, but once you dedicate your car too the track... That's where the party is at. Feel free to contact me if you decide to go BBK. I have a few options.

 

Hey,

This may do the trick beyond scraping the rotors if you want to make the investment not at a bad price.

http://www.m3forum.net/m3forum/showthread.php?t=466214

Same brakes the ALMS BMW RLL team uses.

BTW - Do you have the option to get on the track with top down stock?

Regards,
Loay