I need to know @ what rpm the figures were made to know if they were strange or not.
I suspect that the boost was dropping from midrange and up.

Too many cossie owners are disappointed about their hp numbers after a dyno test. The car feels alot quicker than it really is because of the high torq in the midrange. but at top end boost drops and misfires occur and so on so hp is lower than what it could be.