The BangShift Billy Digital Clutch ControllerThe BangShift Billy is a Digital Clutch Control device for the perfect, repeatable launch for drag racing. Read as: consistency and reduced carnage! What's the problem with drag racing with a street style diaphragm clutch? One of three things: You're either going to spin the tires when you launch the car if you don't the slip just perfect with your foot. You're going to break parts. It's going to bog, then accelerate down the track. That kills your E.