Thanks a lot for the suggestions, tomorrow I´ll try all that, I guess it has something to do with thrust as you mentioned so I´ll see what happens know that it has an ultrathrust muffler (91FX 15x4W APC).

To get more than 45º I´ll get some large servo arms because did some testing in AFPD and there is a real difference between 45º and 60º when doing waterfalls.

I´ll tell you tomorrow