At 500 rwhp, we are already beyond what anyone could or would ever use on the street, and putting that much hp down at the track requires a different platform (chassis-wise) than what we are working with here. At 35 pounds of boost, if this bike can muster 580 or so I will be happy with that. If we could take it to 38 pounds of boost, it would definately break 600 rwhp, its just that ecu editor software has not yet been extended that far. I cannot safely go beyond the range of the fuel mapping for the sake of a "dyno queen" number, and putting the engine at risk. My own personal street Ultra topped 600 rear wheel, and I ventured out one night with a tankful of C16, intending on putting it down on a white concrete stretch of road.
At only 500 horse, I managed to scare the ever living out of myself, trying to keep it on the ground. Ever since then I have been more than happy riding around at "only" 400 rwhp on pump fuel. And that is the real beautiful thing about Ultras - their ability to make big numbers on pump gas.