Retro you are right, it's only revving a little over 9000rpm whereas the modern stuff is revving to about 11,000. I think this is to do with the ignition on the bike which is stock apart from Dyna coils, and is probably breaking down at high boost/rpm. Most hi-performance 750 turbos use a Dyna 2000 or similar to improve the spark. My old dragbike 750 turbo had a programmable DTA ECU with two 6 amp coil drivers and fully mappable igntion and that thing used to rev to 11k in a heartbeat, it also made way more power than my streetbike even though the engine was smaller and it ran less boost (760cc and 23psi instead of 810cc and 30psi), although it did have the added benefit of running on alcohol. So the plan is to fit a new DTA S60 unit to the streetbike over the winter to improve the ignition. In addition the S60 has extensive datalogging facilities, progressive boost control and does away with all the other boxes on the bike.