Well the weekend I got to do a bit of racing with my buddies one feller got a 2006 snopro F7 and the other got the base 2006 F7. Both of the sleds were stock with the 1.375 track and mine got a 1.25 ripsaw, geared down 2 teeth and got Dynamo joes clutch kit(this is the zx-x chassis too not rev). We were racing on a pond with about a foot of fresh snow so really that should give the advantage to the F7's. When we raced I used to take both of them outa the hole and pull them slowly at the start then when we were goin father I would leave them faster. The feller with the sno pro raced a 2006 renegade 800 ho powertech and used to take him for fun after we raced he was pretty surprised he said that i was defently pullin him.