Sound is a home-made circuit bent walkie talkie fashioned into a sort of opto-theremin. Main fx used to process it: boss xtortion and wattson superfuzz, with various other fx switched on and tweaked in the middle. Very much like a chainsaw in the beginning. . . That or a motorbike. The "reving engine" effect was created by blocking the amount of light going to the photocell (which was ripped out of a furby!).
Author: The Semen Incident