ORIGINAL: Xairflyer
Anyone know of a program that can select redrive ratio's, torque prop diameter etc.
What I want to do is say take an engine that will swing a 28x10 prop at 8000rpm and find out if it was fitted with say a 3:1 reduction what prop it would swing, thrust produced etc, and say select prop size and find out what reduction would be needed, or know the prop and reduction and what hp of engine would be needed.
Get the idea !
If you use [link=http://www.mvvs.nl]my spreadsheet[/link] download at the propeller section, you can first take the prop the engine likes best. Grab the power from the spread sheet. Then input the propeller you want to use, and juggle rpm until you find the same power.
divide the found rpm by the original rpm, and voila, there is your reduction.