Was flying 190d last night and thought of this post. I don't fly 190 much in the past. Anyway...
I think they modeled a torque limiter for high manifold pressures in the 190. So if you run the mp's up high, say 1.8 ata with the mw50 or added fuel injection on, you can manually increase the rpms to say 3500 rpm at 100% prop pitch. But you can only lower them down to 3000 rpm at 0% prop pitch due to I guess, the torque limiter in effect. I suppose this makes sense to avoid strain on the crankshaft. So, to decrease further, say 2600 at 0% prop pitch, you must lower the mp's (i.e., turn the mw 50/injection off and reduce throttle). The d9 accelerates really good and you can cruise at very high speed at 1.2-1.3 ata with rads closed. None of this rads at 2, 102 throttle and mw50 all day long. That is not optimal in any case. You waste fuel and have no heat reserve for battle.
