sjasmund

Anyone here have any problems with stock replacement Brembo rotors?

At Grattan last weekend, I developed a pretty decent vibration under braking. I had just switched pad compounds and chalked it up to pad building up on the rotor. I swapped rotors before the next race and found a huge (by my standards) crack in one of the rotors.

I've seen rotors with little spider cracks in the surface before but this crack was all the way through the rotor and ran halfway from the outside to the center. This rotor had only 2 race weekends on it.... ARRC, which is tough on brakes and IRP, which is not.

Drew M

There have been a good number of Brembo rotor problems recently. Most have been on the 1999 Mustang Cobra's rotors (Brembo blanks) but I imagine the problem could occur in any rotors.

Brembo said they have resolved the issue however.

phat-S

Scott, I don't know if this is helpful or not. About a year ago at VIR there was a BMWCCA event and it could have been called Brake Break Fest. I think there were 6 E36s and 1 911 that cracked good rotors (not aged stuff). They all cracked the outer rotor as I recall and after the first three or four people started comparing notes. The consensus by the end of Saturday was that the mid 40s temps and the long fast straights were over cooling the rotors and cracking them (as they all had ductwork that blew into the hats hitting the outer rotor). Most everyone as I recall was taping their brake ducts Sunday (except my instructor and someone else who later Sunday cracked rotors). I am sure this is a easily arguable topic and I am not saying for a minute "this is the problem" or "this is what happens" b/c I don't fashion myself an expert. What I do know is that I have removed the ducts for the events that I have run in colder temps (40s) and in the rain. I have gotten some good life out of mine although that is probably just luck.

No clue if this is remotely valid data.

sjasmund

Adam... Very interesting!

I ran the test day on Friday without problems and it was about 70F outside. The problem developed on Saturday when the temperature was... drumroll please... about 42 degrees! I have ducts routed to the rotors and did not have them taped off. I guess I'll try taping them the next cold race we have.

phat-S

It would be great if that's the fix. Good luck.

BTW, double ECR at VIR Full 11-2/11-3 - hint-hint-wink-wink cm'on maaaan!

vwong

yeah....that is interesting. I've never thought about that. But after reading Adam's post, it does make sense. Due to the cold ambient temperature and brake ducts (and the long fast straight), the rotors get cooled much quicker. And it's this constant cooling and heating that would cause more rapid contraction and expansion, and eventually cracks on the rotors. However, if the ducts are taped off, the rate of contraction and expansion is slower and less tendency to crack the rotors.

sjasmund

That's the week before ARRC!

On one hand, it would be nice to get in two races and only have to make the 12-hour tow once. On the other hand, I run the risk of doing major maintenance in my trailer in the parking lot of some hotel between VIR and RA.

"Whadaya mean the other guests are complaining about the generator, compressor and air tools?!"

I am planning on coming down for an event at VIR sometime this year. What I want to know is... when are all you guys going to drag your cars up to Mid-Ohio?

phat-S

If you want, leave from VIR (2.5 hours) and take my trailer spot (secured parking lot) - enclosed trailer right? I'll get you the code and you can get in and out at your leisure (2 miles from dtown Charlotte). If its not enclosed, I am sure I could put the p-car somewhere (hell the CRX will very likely not be here - be at my co-driver's - between VIR and the ARRC anyway so I'll have a garage space and just get you the clicker thing). So you bull**** around Charlotte Mon-Tues and follow me down to Brassleton (sp) Wednesday (3 and a half hours). Then after the ARRC, you are still the same distance you were from home at VIR.

Thoughts?

TDRacing

At SIR a few weeks ago, my dad brought his type-R down for a race. The race before, we had installed new Endless pads on some Brembos that were about 4 races old. 1 lap in to the practice, the brakes started shaking and the car was undrivable. We quickly drove out to some little autoparts store and picked up some Valu-Max pads(made in china) for $29 a rotor. We put them on, missed first qualifying, but made it for second. The pads performed really good for what they were, and lasted 2 races.
A RULE FOR ALL: bring an extra set of rotors with you to the track.

EagleR

Blan off the brake ductsif its that cold and there are long straights.....I've had this happen as well....

sjasmund

Adam... that's tempting. I'll have to see how the season goes between now and then and talk my wife into visiting Charlotte for a couple days.

phat-S

Cool man. Let me know if I can get you any Charlotte info for the "why we should go" list.