The 9x6 prop turning 12K has a speed potential of 72 MPH. Not
exactly slow Nerf speed. And a number of us, L.T. for example could port and retime that thing and add 1500 RPM. And it would not be evident by looking at it from the outside. Now that would add 9 MPH to it's speed potential.
Good luck. I hope you can make it work.
Cajun