Erich Trombley a crit :
>
> Simon,
>
> Can't say I agree with your assessment. The MP gage in the panel is
> independent of the airbox pressure/TCU. As part of the installation
> of a MP (electronic not analog) you are required to calibrate the
> sensor. If the sensor is off by any amount from the true MP that the
> engine is really producing then you will be incorrect in you
> assumption of H.P. For example if the pilot has not correctly
> calibrated the MP gage and it is reading 31" of MP, however, in
> reality the engine is producing 34" then that would explain the
> excessive fuel flow for a given MP reading. Make sense. Off course
> too rich of a mixture could also be the cause, however, with the Bing
> carbs this is unlikely. My fuel flows per indicated MP are very close
> to the published figures in the Rotax manual. Just my two cents.
>
Hi all,
You need to check the MP gauge and the tachometer.
We checked ours during the flight tests, and our UMA tachometer read
high by nearly 100 RPM at 5000 RPM. I mean, when it read 5000, the
electronic calibration tacho read only about 4900 RPM.
Now, suppose yours says 5000 while the engine is turning at 5100 ? If I
recall correctly, prop power varies with the cube of RPM...
FWIW,
Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr
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