Sorry guys I'm no expert on these things but I would like to suggest something. You guys tried one of the high discharge packs like a Kokam 3S 910mah? I am just wondering if the packs you are using can handle the amp draw and so on. The last one I tried to fly we ran into these problems with the small packs not being able to supply the power needed when the pitch starts goin on these things. We then switched to the 3S 910 kokam and it was much better. I didn't build the plane I flew though and we're still new at this thing so the prop ate the plane up before we could go into negative. Got enough power upright though