The rpm readout is not off, not from other folk I have talked to, that is also taken off the bike,so one can match it with the bikes tach to check. If you have tuneboy set at 7k I think the rpm limit is different in some gears. I have noticed this on many bikes all on the same dyno. Normally a stock unflashed rocket has higher rpm in the lower gears. When Nels tested your bike, he had yet to receive the latest version of winpep 8. The early versions were released with no other CF adjustment than SAE. NO DIN STD PS etc etc, that would account for 2.4%. I would suggest the win 7 guy used a different gear to test the bike?? The hp calculation on the dyno is from the physics equation Force equals mass x acceleration ( think I remembered that right

) The rpm pick up is only to calculate torque. There is a speed sensor on the dyno, and the rotating mass of the dyno is individually measured in the factory and a code assigned. One can do a plain HP readout with speed on the lower axis and no rpm at all.