BINGO...after all, the DF is really only a prop with a shroud... AND this is the entire basis for my argument. If you have a more powerful engine for your conventional prop, do you expect mor thrust?...or do you just accept what you are told and that there doesnt exist a bigger prop so dont dare even explore the concept?...

There appears to be another conclusion..that the DF fans on the market are optimised for best mix of speed and acceleration... and that may mean at the expense of static and/or dynamic thrust...that's fine. If you have plenty of power, you can get more than 13 lb thrust from a 5.25 inch, and 6 inch fan also, provided you match the fan to your engine's characteristics. But to be told and abused for asking is not fine. Especially since it appears that what the "theory" suggests, is infact, correct. (well countsarnit!, who'd 'v thought?)

and yes, grbaker..you must have been reading another thread... it was mentioned that a bottom of the line turbine generates 18 lb thrust...., and that you should be able to get up to 25 lb with perfect fan, no losses, no turbine...and it was also clearly stated that top speeds were not required...

regarding what i want to hear.., well no again...(you're not doing too well are you?)...i cant dismiss what people have seen can i?... and i never did, did i??... what i did do was ask about how the result was achieved.

after explaining myself about how i thought aht more power/ proper fan aselection should give more than 13 lb, i already figured why- i just needed to hear that someone else had figured the same thing... so there's no need to question that one is there?

sigh...