I've only raced an FZ07 with a stock motor, Yoshi pipe and PCV on pump gas. On the dyno It made 71hp at 9000rpm. It fell off to 60hp at red line because of that ridiculous air box, long v stacks and small air filter. Should be fine on tight and twisty tracks, but it will suffer on the longer straights. A LW twins class would be cool.....
I never got to race mine before I sold it to Joe, but even on the straights at NOLA it wasn't bad. The stock airbox absolutely sucks, but I still felt like the overall package in SS form was better than my SS SV650.
Going to MotoJoes house tomorrow to mock up some bits on his to do my part to get him treaty to get back out there. I may have to borrow it until he's ready. Apparantly a damn fun bike to ride.