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Full Version: Throttle position vs MAP
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I was just curious if anyone else had noticed this in their naturally aspirated ships as well, it's something I always wondered about but never has been an issue.

My throttle position sensor reads accurately on the FADEC but anything above about 70% throttle position does not make any power difference and it's at full MAP by then, so I just never open more beyond that. Is this because the manifold pressure reaches ambient pressure at a ~70% throttle position, so opening further does not make it breathe any better? My DA ranges from 2,000' to 6,000' where I currently live. I never paid attention to throttle position when flying at lower elevations so I can't compare.
(12-24-2025, 09:21 PM)Jared Hartzell Wrote: [ -> ]I was just curious if anyone else had noticed this in their naturally aspirated ships as well, it's something I always wondered about but never has been an issue.

My throttle position sensor reads accurately on the FADEC but anything above about 70% throttle position does not make any power difference and it's at full MAP by then, so I just never open more beyond that. Is this because the manifold pressure reaches ambient pressure at a ~70% throttle position, so opening further does not make it breathe any better? My DA ranges from 2,000' to 6,000' where I currently live. I never paid attention to throttle position when flying at lower elevations so I can't compare.
I would say that is true.  My Non-turbo Bonanza at higher altitudes would only get Manifold Pressure up to ambient pressure.  Always ran full throttle but used mixture to control the fuel flow / consumption.  Your FADEC does that for you.