Hi All.
I have a BVM .91 ICDF with viofan I have in my Mirage 3.
I am strugling to get a good static thrust on this setup, the engine screams like a banshee so I think that part is OK but the thrust at the outlet of tube just "feels" weak.
I tried to measure it by having the nose of the jet pushing against my scale (scale standng vertical) and it only read about 2800 gr.

My thrust tube exit is 95mm (just over 3.75 in) diameter. It woeks out to be 81% of fan swept area.

Is this setup restricting the flow to much? I cant really alter the length of the thrust tube setup, only the outlet diameter id needed.

Would a 100% FSA exit size still give OK , not blistering fast, flight thrust?

Thanx

Theuns