First, go to the map were there is 2 power gravity things that make u fly, than, put a gravity lift........ oh wait go to forge than do all this stuff. Anyways put a gravity lift in front of the gravity thing maybe like a couple inches farther in each gravity thing. then ride a mongoose over the gravity thing and u should go back and forth. have fun!!!P.S BEWARE IF THERE 2 OF U GOIN AT THE SAME TIME YOULL BOTH DIE