mdfud

First track day with my 2011 C2S. Has about 20K, I am the second owner. From what I can tell, rotors and pads are OEM, first owner said he'd never tracked it. First two sessions (25 min each) no sound from brakes but each of the last four sessions the brakes made a humming noise when hot (when I went hard on the brakes it sounded like the horn was honking). Never had this happen with previous cars (993, 964). Pads and rotors look fine. Anybody experience this? TIA.

voiceprint1

not an expert on tracking, but you're running a car that has 9+ years on the same pad and rotor and throwing it into 5 track sessions, that might expose any issue, warping, uneven wear ect. you don't mention changing out the brake fluid?

mdfud

Changed the brake fluid before tracking. It was a little nasty, looked like it hadn’t been changed in a while. Didn’t think about aging as a possible contributor.. Thanks for the reply.

Petza914

Street compound pad material isn't really designed for the high temps you see on a track. The compounds are designed to work at lower temperatures and have high initial bite. On a track they don't get the same type of cooling down opportunity they do on the street. I would drop in some more task specific race pads before your next track day and see if that doesn't work better. When swapping pads, you need to clean the rotor surfaces really well to remove the microscopic layer of pad material that gets deposited into the rotor.

Bruce In Philly

2009 C2S 155K miles

The first time at the track in my 2000 Boxster S, stock everything, freaked me out. When the brakes got hot, they made all kinds of scary noises... for me, it was like bad metal on bad metal. Scraping sounds more than anything. Instructor said it was totally normal. For all my track days, I kept pads totally stock and never experienced any brake fade. The group rules were that your fluid could not be older than 30 days... and I kept to that.

When you are not running, go to one of the corners and listen to the cars coming in... those hot brakes make all kinds of whacky, scary noised. Normal.

Regarding running after-market pads..... folks love to change stuff out... it is part of the fun of ownership, but Porsche brakes, oiling, and cooling are "track ready" right off the showroom floor.... that is one of the things you pay for.

Peace
Bruce in Philly