Percent Power without MAP

[jshultz]

Some engines don't have any provision for MAP sensors, but the manufacturer lists power tables according to RPM and fuel flow.  It would be nice to be able to enter this data into the EMS using RPM and density altitude.  With a fixed pitch prop RPM is an acceptable substitute for MAP and a correlation can be entered by the user as a table of figures (i.e. % power for a specific RPM reading at a specific DA).

I've included an example of what I'm talking about to help explain.

 

[dynonsupport]

I'm assuming that this engine also doesn't have mixture, correct? If so, what does % power tell you that RPM or FF doesn't? What kind of operational changes do you make when you see 81% power or 87% power?

Also, the table doesn't isolate TAS, so this is invalid if you aren't going the speed of the table.