I wouldn't sweat the calculation on what it thinks your crank power is.. Most of the time I see people use 18% drivetrain loss for BMWs.. Which would put you up at 177 at the crank... M50 horsepower is published as 189hp at 5900 rpm...
I'd say that is close enough... Different dyno's, different locations, weather conditions, etc.. all affect performance. Not to mention the lower octane fuel.
Intake and exhaust are not going to get you much performance gains without tuning, and that tuning would need to be for high octane fuel. |