i would have thought with not having the drag of the tyres and rotational mass of the wheels then the readings would be higher yes but that seems a little extreme, i wouldnt trust dyno figures anyway as its all down to who operates them as to what figure you will get anyway they are allright for a ballpark figure but thats about it
i personally couldnt give a toss what bhp and torque my car makes all i care about is that its setup right and isnt going to melt when i give it some!