Boy not much action in this forum.

I've got E-Flights Extra 260 profile with thier recommended VPP setup (accept for battery, older 3S 800maH). I use thier 370 hollow shaft 1200kv motor with thier showstopper VPP set-up. It weighs about 11.7 oz with battery.

My question is why doesn't it seem to have the same thrust in reverse as forward? It will climb quite well forward, but I can only get it stop inverted.

Throttle curves, pitch curves, etc are all as close a humanly possible to being symetric/same. In fact it is quite easy to physically check the pitch forward and reverse because the prop folds and you can simply measure tip to tip. It is also easy to confirm center/zero pitch.

If we assume all that is correct, what could cause a difference in thrust from forward to reverse?

About the only thing I can think of is the fuselage. When the air passes over the fuse normally (forward) it flows straighter down. But when inverted, the air is allowed to move around more (perhaps in a spiral and outward).

Thoughts?