24d wrote:So now we have a car motor turning 6,000 RPM making 350 HP going thu a gear box turning a prop 2,000 RPM then when you back the prop down to 1,000 RPM your motor is turning 3,000, you just lost at least twice but more than likely three times the HP the aircraft engine did doing the thing.

I'm not putting down a car motor but thats the basic math of it.

24d

A given--- Descent prop on both engines.

carmotor probably makes 350 horse @5252 and makes 350 torque @5252 and each # at the flywheel. Using a 3 to 1 redrive, we then have 1050 # torque at the output shaft on auto engine's redrive @5252 rpm.

In your basic math of it scenario's, how much thrust is lost in each scenario using torque to spin each propellor, and then decreasing each prop's rpm by say 1/2 ??

Torque spins each prop. Right?