Learn from my experience. Do not underestimate the toll that track use can have on our OEM brake pads. As mentioned in a related thread http://www.s2000online.com/forums/showthre...hp?threadid=987 , track use is very hard on brakes, even the excellent ones that we have on the S2K. I was warned by a couple of different track veterans that the short course at Sebring is very hard on brakes. There are two relatively high speed straights (100+ mph in the S2K) followed by slow corners. That, coupled with an extended technical section that requires several more brake applications, means that there is little chance for your brakes to cool.

I prepared for the event by flushing brake fluid and bleeding the system (one good decision), and by inspecting the pads. They had about 80% of their original thickness so I thought they would be fine (one bad decision). Fortunately, I had listened to the advice of people that knew the course and had an extra set of pads on hand (another good decision).

The morning session was a blast, and when I inspected the brakes before lunch, they looked fine. But, I didn't bother to get a really good look (another bad decision). The afternoon session started out strong, I had been catching up with a BMW 3 series for a couple of laps and knew I would take him in the next passing zone, but first we had to negotiate the "hairpin" that followed a very fast section. My braking point arrived and I pushed down on the pedal, and then came a big shock ... WHERE ARE THE BRAKES . It took a lot more pedal pressure than ever before, and I got the car slowed down, but not enough. I'm not sure how, but we averted a collision. Fortunately, the pit entrance was just after the hairpin. After apologizing for scaring the sh!t out of the BMW driver, I drove to my pit area. As Ole and Sondra will attest, I had that "deer in the headlight" look, but they were nice enough not to make a big deal out of it. The car went up on a jack and with the wheels off, I could immediately see the problem. The brakes pads were worn out!


Note how thin the material is on these front pads and that the metal clip that warns you when the pad is low has BROKEN OFF of one! I had thought that I heard a strange noise in the previous lap, but I was following a spec racer and its loud exhaust note made hearing my car difficult. Lesson #2 - listen to your gut. When you think something is wrong, pit the car and check.



Note the color distortions on the pad shim indicating excessive heat exposure!



So please let this be a lesson for all of us. Participating in track events is an excellent way to learn the performance limits of our car ... just be CERTAIN that your equipment is safe.

 

joshua - how many track miles were on the pads before you went to *this* event?

I have found out that i can get 1 day at the track, and still be able to drive the car home.

If i used the pads on the street before hand, that is fine (they don't wear out very quickly that way), but just that one day (80 minutes) ends all track fun!

I did attempt last time to just have the fronts switched, but..... my rears were actually heat cracked and 75%+ gone anyway.

Scot

 

These were the original pads with about 9000 miles of street use plus 3 autocrosses thrown in. I also used them in an earlier track event that wasn't nearly as intense on the brakes. It was surprising that after lasting through all of this, they wore down in just under 140 miles of Sebring Short Course Track use. I guess that as I become a better driver, I brake harder and go through pads more quickly. You may be able to see in the photo that the pad surface is glazed in places and in others it appears to be chalky. Is the chalkiness what you mean by burned?

 

Well you used those up pretty well!

You are right, as you get more experienced with track driving you naturally are more aggressive and drive deeper into the turns using more brake. Those pads go very fast on some courses.

I

 

Joshua,

Man, your brakes are really used up! I can't believe the heat scoring on the small metal plate! I'll need to look over my pads before I try anything "harder" on the car than autocrossing!