pantyraider

Went to the track this past weekend, and had smoke coming from the rear brake pads after one session. I'm not concerned about it, but I'm curious why they did since braking is more biased to the front pads. Any guesses?

Sri

Fongu

Just to be sure, did you forget and leave the parking brake on? If you didn't know already, you shouldn't use the parking brake at all between sessions.

Otherwise, even though front brakes do more work, this car's brakes seem to be very well designed with properly sized. I recently used up the OEM brake pads in a lapping day. When I checked them they all wore out at the same time, indicating that the braking "power" was properly distributed. Other things effect brake bias also. Give this a read:
http://www.stoptech.com/whitepapers/brakeb...performance.htm

If you are still using OEM pads and are braking hard and often enough, you can overheat the pads causing them to crumble. It might be time to start thinking about a more capable brake pad.

pantyraider

No, the parking brake wasn't on. I think you may be right about switching to something other than OEM because by the end of the day my brakes were almost useless. Although, this could have been because of the crusty, old brake fluid that I didn't have time to change out.

The interesting thing though is that the track (Big track at Willow Springs) isn't supposed to be very hard on the brakes compared to one I ran two weeks ago (Streets). But I didn't experience any fade/smoke/etc. at Streets which is much more twisty.

Thanks for the link to that paper. Interesting read. I have 225's S03's on the front, maybe the larger contact patch causes the rear brakes to do more work? At any rate, I think I'm going to switch to Cobalt GT's. Thanks.

Fongu

I took a look at the track maps. If I had to guess the big track would wear tires and brakes more, just because of the higher speeds. There seems to be fairly large areas where the brakes could rest and cool, so no sustained overheating. The Streets is more compact and with a lot of braking zones distributed through the track. Suspect that the brakes had less time to cool and had a higher average temp.

Old brake fluid is definitely mushy pedal time for a sufficiently fast driver.

RACER

Although there is sufficient space between hard braking areas to allow the brakes to cool, Braking from 110+ mph causes substantial friction causing heavy wear.