All tracks, minus IGYEIH, were already written in programmed drums. He did some fills here and there. The one he could really create something on the spot was IGYEIH.
The first time he heard Two Faced he said "i love it, it's nu metal" and Mike said "NEVER SAY IT AGAIN"
In many interviews till now he talked on how he doesn't need double pedal. he can do a lot fast stuff with one.