Have you guys heard of a "Rave"
 

A buddy of mine "claims" that his friend some sort of device that he can freely attach to the back of zip, near the motor I'm guessing that makes it run really fast. I've searched for the term and could find it on this board. Just wanted to throw this out there to see if my friend's friend is just bull****ting.''

Thanks

could be a secondary battery but that would make the engine run uncontorlably. he might be able to contorol it a bit with the normal controls but i think he's full of s**t

dude dual cell's are common in the bit/zip world and don't make you're motor run uncontrolably..... also most dual cell's are very controlable as long as you're not trying to pin it all the way around the turn..... but as for thinking he's full of sh|t i kinda agree.... untill he has more proof ie. pics

what do you mean my back? back of the pcb or motor?
if its the back of the motor he could be running wires to the pcb or connecting the box directly to the motor.
if its the back of the pcb its probably just a second cell