Hi Dave,
I agree with your conclusion but I'm trying to get my head around the statement that geared systems have more torque and if so how that affects driving the prop system. Are you referring to the popular systems we use? It would seem that two systems driving the same prop at the same rpm would require the same torque. Or is there a difference in accelerating the prop or props?
I'm still trying to learn.
Jim O
Hi Jim,
I think from a narrative perspective, "we" have come to use phrases like "more torque" in imprecise ways
My intent was to convey that a geared system generally has peak torque available over a broader RPM range (when compared to direct drive) and a geared contra system has a broader torque range than a geared single prop system. So, the contra has "more torque" when considering the full range of throttle. In practice, when transitioning from horizontal flight to a climb, the airspeed lost (given constant throttle position) is the least with a contra, and the most with direct drive. And with the larger surface area in the prop disk of the contra (and the taller gearing), the braking effects are also greater, so the end result is less throttle work is required to fly constant speed.