Tina wrote in news:f9933f5e-0c1d-464b-a1d8-
:

The Mooney 201 has a ram air port, a half a foot under the prop
spinner. The POH tells us it can be opened at altitude for a very
modest increase in MP and we find maybe a half inch increase in
pressure. The idea of the thing is, if the port is looking right at
the air being thrust toward it by the prop (it can't be more than 6
inches or so behind it) as well as the air impact from the airplane's
motion the air being 'rammed' into it should effectively lower the
altitude the engine thinks it's at. Well, a half inch of Hg is about
500 feet or so. The question is, though, wouldn't you think there
would be a way to capture a great deal more of the ram air effect and
really boost the engine performance? Who wouldn't like to fly at 24
square at 12000 feet without a turbo charger?

What makes me wonder about it is, even at 60 mph holding your hand out
of the window of a car subjects it to a significant backward pressure,
so the energy must be there.



Didn't know any production aircraft had that. Well, to some extent
almost every lightplane does . that's why the carb air intake faces
forwards in most of them.Everything is a balancing act with an airplane.
More air = more drag. You could try putting a couple of woks with tubes
out the back to boost your MP, but you're going to pay for it. !Moooney
must have spotted an area of the cowl that would not penalise you in
this way and decided to utilise it. Really clever homebuilders do a lot
of this kind of stuff as well as, and probably more more importantly,
dealing with cooling drag.
Have you put the other speed mods on your airplane? I think there's
nearly ten knots available in seals and various other tidy it up
fairings.

Bertie