On Mon, 3 Oct 2005 15:32:04 -0400, "John Doe"
wrote:

Ok, another turbo question:

Can someone please explain to me the performance gain by going above 30" MP
(say, during takeoff) on a turbo'd engine.

How much better performance are you getting from the engine at say 35"MP on
takeoff vs a non-turbo'd engine that's going to max out around 29"?

Is it worth the strain put on the engine? I understand the turbo being able
to maintain power at high altitudes, but I haven't heard it explained to me
why I would need such a high power setting on takeoff/climb (assuming sea
level field).

I'm not sure exactly what you are asking for. If you are taking off @
sea level on a standard day the performance difference between a
turbo-supercharged engine rated @ 300 HP and a normally aspirated
engine rated @ 300 HP is ZERO.

During cruise flight, the performance difference between both engines
at 65% or 75% power is ZERO.

The "better performance" is derived by being able to develop rated TO
power on the turbo-supercharged engine above sea level on a
non-standard day. It also allows you to use cruise power settings at
higher altitudes than a normally-aspirated engine.

As one responder indicated, if your engine is rated @ 300 HP/36"
MAP/2700 RPM, reducing either the MAP or the RPM is reducing the HP
developed.

TC