If Porny comes along he may be able to confirm, but:
Without boost box to fool the ecu you won't go too far wrong if you increase boost in small steps until you feel engine 'misfiring' on heavy load/full throttle. (I.e. feels like a momentary misfire in a petrol car). Accelerating up a hill in a high gear will usually show it up. If you get to this point, back the actuator rod off a little and that's as much boost as you will be able to get before the standard limit it reached.
More boost should make the engine feel livlier, even at lower throttle openings (Revs pick up more readily).
Anything like this, though, Porny's the kiddie!
Graeme
