Good info in both threads ( here and the link that DarZeelon mentioned ).

Now , let me make a crazy question , do you think a shortened prop let's say an APC 12x14 to 9x14 will produce "similar" load than a stock 12x8 or 12x9 prop and run properly on the 91 FX ??? I'm considering 1"= 2pitch I know that the wider blade of the 12" prop would pruduce more load than a normal 9" blade stock prop due to the total area , that's why I'm saying also an 12x9.

My thoughts are , if the power of the 91FX is able to move the 9x14 prop near to 12k (with tuned pipe of course) we would have a "cheap" engine doing 168,000 " per minute .... in theory , would be this kinf of "equivalent" to have an 8 pitch prop spinning at 21k ??? , 8 x 21,000 =168,000 ". Yes I'm thinking on SPEED .

I'm losing my mind or I'm getting a chance ??? [&:]