I'm afraid it is Mr. Martin who needs the lesson. This is dangerous nonsense.
The brand of constant speed propeller, airframe and equipment have nothing to do with the setting of the engine throttle.
The throttle controls manifold pressure.
The manifold pressure controls the torque of the engine.
The resistance of the propeller in a fixed pitch determines the engine rpm for the developed torque and this relationship is fixed by the builder of the aircraft.
However with a constant speed propeller, the propeller pitch is adjusted by the pilot through the controller to maintain a constant rpm at a set value independent of torque.
The whole purpose of a constant speed propeller is to maintain the exact performance conditions (torque X rpm = power) specified by the manufacturer of engine for best power, economy or reliability of the engine. Typically this is specified for full power, maximum continuous power, 75%, 65%, 50%, etc.) The purpose of doing this is to maximise aircraft performance across the whole range of its operations (takeoff, climb, cruise) without having to make the tradeoffs required with a fixed pitch propeller.
The fuel mixture, spark advance, etc. is determined by the ECU with reference to airbox pressure, manifold pressure, air temperature, rpm and EGT to develop the performance. These variables will change with temperature and air density. They have nothing directly to do with power, the ECU contains a map of all these variables and sets fuel flow according to all of them.
Rotax needs to specify exactly what rpm and manifold pressure the company requires the engine to be run at to develop the advertised levels of performance. In part this is necessary because many engines have dangerous combinations of rpm and MAP that will cause premature engine failure, for example with the Rotax it would probably not be advisable to try to run it at 5000 rpm at 29 inches MAP, the engine might destroy itself.
To put that another way, the pilot has direct control of rpm and MAP with a constant speed propeller but no control of fuel flow, which is handled by the ECU. We wish to know the throttle and rpm settings Rotax wants us to achieve.
Alternatively, Rotax can provide an official statement in the engine operating instructions as to exactly how it requires the power and rpm to be set when using a constant speed propeller if this is different from the method taught to pilots for at least the last Sixty years.
