Ira,
You misread me. I said that a given combination of MP and RPM gives you
more power at altitude. I am not talking about max full throttle power.
Of course I agree that full throttle power decreases with altitude on
any normally aspirated engine.
Go back to the SR20 exemple: flying at 8000 ft, 2500 rpm and 21.2" MAP
give you 65% power. Now flying at 2000 ft you need 23.8" of MAP to get
the same 65% power at the same 2500 RPM, so obviously if you fly at 2500
rpm and 21.2" MAP at 2000 ft you will get less than 65% power. At 2000
ft the ISA temperature is 11degC while at 8000ft it is -1 degC.
Therefore the density of the air at the same 21.2" pressure is higher at
8000 ft than it is at 2000ft. That is why this 2500 rpm and 21.2" MAP
setting will give you more power at 8000 ft than the same setting at
2000 ft. From my calculation this setting will give 62% power at 2000
ft. That is just the laws of physics and all aircraft engine
manufacturers seems to agree with them.
Cheers
Remi
>>>>>> Your suggestion that a normally aspirated engine
will develop more power at 8000' than at 1000' is quite curious.<<<<<<<
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