What does the Manifold pressure show?

[Golfer]

No frank.  You've got 400mph of wind blowing over that propeller spinning it and the RPMs just aren't going to come down when you've got all that 'help' pushing the propeller around.

[CAP1]

Manifold pressure=power output of the engine
it is controled by the throttle. RPM= speed of the engine and prop. It is controled by a governer.

You set the manifold pressure to your desired output, then advance the prop to set the desired RPM. some aircraft do this automaticly. I would imagine it is also done automaticly in AH too.

hope this helps?
john