I had a CF DF clutch in my lil n/a motor and it slipped on DR's. Those clutches suck. They have organic material on the PP side and some other type of material on FW side. Aside from some of Mcleod's PP that increase clamping force as rpms increase all the diaphram PP's are all the same (valeo). So if you're going to get a diaphram clutch make sure you get a good disk with some decent material (at a minimum kevlar). Some of the more agressive clutches come with cermaic or carbon and you can get them in a puck style or full face. Be warned, more agressive clutches will tend to engage like a light switch (on/off). You got to give a little if you want it to hold a lot of power.

-Mark

EDIT: your disk is a DFX like Hurst said. PP looks valeo.