I mean that with boost controller off, engine load is around 170-175kpa at start of boost until rev limiter at 6400.
With boost controller at 50% duty cycle, engine load starts around 200kpa at start boost and drops reaches 175kpa at 6400.
So from this (and from the fact that peak power at the dyno got 280bhp with 0.7 bar of boost@6000 rpm) i reach the conclusion that its better to shift gear instead of pulling the car over 6400rpm.
Original engine rev limiter is at 7200rpm. Engine size is 1998cc and the turbo is GT28RS with 0.6 A/R. Checking and calculating the compressor maps of this turbo against engine size indicates that the turbo is efficient at 0.7-1.2 bar