The best OEM performance element of a Boxster, on the track, is the brakes. This is particularly true if you have the "S" version. You can out brake any other car.
The weak link is the rotors - particularly on the front. With heat cycling, the OEM cross-drilled rotors develop cracks from hole to hole. When this occurs, they need to be replaced. The Performance Friction, two-piece, dimpled, front rotors are a good alternative. Cracks aren't a problem with these rotors, and when the rotor wears down, you can keep the top hat and simply replace the rotor element.
OEM street pads will not hold up under track conditions - even DE events. Pagid, PFC, and Hawk all make track-worthy alternatives. My current preference is Hawk DTC 70's on the front and DTC 60's on the rear. Replacing the pads is a simple procedure. You need a jack, an 18 mm socket, a needle nose pliers, and a vice grips. If you drive your car on the street, put the OEM pads in the calipers. Replace them with "track pads" when you go to the track.
If you're on the track with your car, you need to have a high-temp brake fluid. There are many options. I currently use Motul 600, but there are others. High performance brake fluid is hydroscopic, and needs to be changed periodically.
If you do a number of track events each year, you'll need to have the calipers rebuilt. How often, depends on how many miles you do on the track, and how much you use the brakes.
If you have a 986 or 987 with PSM, the computer will use the rear brakes to stabilize the car - of course this depends on how you drive on track. If you're finding that the rear pads are wearing out and the calipers are turning "purple", this is your problem. Turn the PSM off, or slow down. Of note - If you've turned off the PSM, when you activate the ABS, the computer will turn the PSM back on.
Ultimately, the trick to going fast around a track is to not use the brakes! Boxsters (and Caymans) are wonderfully balanced cars. If you can learn how to do it, you can get around a track using the brakes sparingly.
I'm still learning.
PCS5978
www.M96infosource.com