Originally Posted by
Aucky
... at sea level it's around 14"MAP. And he higher the altitude the lower this reading as atmospheric pressure decreases. So around 5000ft it's approximately 11-12"MAP.
Tested today: 11.5 inHG MAP (102% RRPM, collective fully down)
Elev: 5,100 FT
OAT: 30 deg C
QNH: 1021 mb
Density ALT: around 8,100 FT
So with the low and high extremes being indicated correctly by the MAP gauge (both station pressure with engine off, and MAP reading with collective down, 102% RRPM), where to look now?
Can't be a "bad engine", misreading gauge or a leak in the vacuum line anymore. The only explanation fitting all data points I can see is "more efficient induction system" / cleaner air filter, as was mentioned by some Ppruners. Sounds also almost too good to be true
In particular, this result doesn't suggest I was actually using less-than-MCP when the gauge says that I am using MCP. (I was secretly hoping I could open more throttle without exceeding MCP, thereby coming closer to VNE in straight & level flight...).