RP-X(TM) Racing Front Brake Pads by EBC(R). EBC Racings RP-X compound is an ultra-high performance track and race pad designed for performance vehicles driven hard on track and for dedicated race cars. RP-X has a very stable friction coefficient of 0.55 mu up to and beyond 850 C, making it an excellent performer for even the most demanding vehicle applications. EBC RPX Race Brake Pads; Front; 350 Disc Diameter; 32/30 Disc Thickness;