Aircraft manager feature question.

[Aleksandar]

Hey there. Not sure why this isn't addressed in the manual, but what are we supposed to use the "Manifold Pressure Target" and "Fuel Flow at Manifold Pressure Target" features for on the General tab?  Also not addressed is the difference between the Iskra Starter (always selected by default) and the C24ST5?

Thanks.

p.s. for minor update - the tiedowns and fuselage cover are not persistent between flights.

[Coop]

The manifold pressure target and fuel flow at manifold pressure target are used to adjust the power on the TN as the engine ages. If you are noticing either too high or too low MP at full throttle, the first can be adjusted. The second can be adjusted if the fuel flow is too rich or too lean.

[Aleksandar]

On 10/19/2020 at 10:34 AM, Coop said:

The manifold pressure target and fuel flow at manifold pressure target are used to adjust the power on the TN as the engine ages. If you are noticing either too high or too low MP at full throttle, the first can be adjusted. The second can be adjusted if the fuel flow is too rich or too lean.

Ok, interesting.  So is this like asking an AME to tune the engine then? 

Help me understand a bit more: so if I go full throttle, as in on takeoff, and I find my MP is in the red (didn't see any limit posted in the manual), I'd bring that down? How would we identify the mixture level; based on experience in the aircraft?

Thanks.

[Coop]

Here is a description from the physics model programmer: 

It is normal for MP to overshoot the default target of 29.6“ on takeoff because the MP controller is an inert device and depends on engine oil pressure to close the turbocharger wastegates. When oil temperature is lower, as usually on takeoff if not thoroughly warmed up to ~180F before, oil pressure is higher and the MP controller target point shifts above 29,6“ (higher pressure closing the wastegate). It is indeed highly sensitive to oil temperature changes and will be unacceptably high below 165F. As the manual suggests it is acceptable for MP to rise into the caution range for 2 minutes on takeoff as you can be sure about oil temperature to rise quickly after takeoff.
The Manifold Pressure Target slider indeed replicates a setscrew a real mechanic has to adjust the manifold pressure target at 180F oil temperature, it can be used e.g. to tune a particular engine‘s full power output down if CHTs are unacceptably high. The Fuel Flow at MP Target slider adjusts another setscrew to control fuel flow at full throttle and 29,6“ of MP. Again this can be used to control engine temperatures on a particular engine or power output, as e.g. on very hot days with thin air the fuel flow should probably be slightly lower to avoid too rich mixtures at full throttle. As a summary, the sliders are probably more interesting for real aircraft owners to tune the simulated engine to the parameters of their real one.

[Aleksandar]

That's great, thank you! I'm certain I've moved it, and not sure where default was, so I've set the circle to the little blue line for now.  Seemed great, though had to watch my CHT's on climbout.  Seems to be tricky on this plane!