I drive an slk230, I occasionally race autocross, trackdays, etc and am wondering if changing to sloted or drilled rotors and changing to porterfield pads will help with my breaking?

 

Porterfield R4-S pads will help. I am just getting started in autocross and with three events left locally, I won't make any changes until spring. I am thinking of Carbotech's new Bobcat pads. The local autocross board seems to favor them for autocross and light track work.

Drilled rotors are a styling gimmick. Try slotted rotors. They are stronger than drilled and are much more effective at getting rid of gas and dust between the pads and rotor.

 

I wouldn't go so far as to say they are a gimmick but slotted rotors are way better than cross drilled. Try porterfield pads. I have no real data but my butt dyno feels the difference.