Used the old pids which flew fine before with this unit. Added two more cells as every once in a while you could see some channels clipping in high wind. With the 8 cell packs it just simply flipped. Too aggressive of a tune causing an oscillation? It’s a real short read on this log if anyone’s interested lol!
Specs:
Firmware 3.4rc2 (been using it in other X8’s and it been really good)
1300mm X8
Tmotor U8170 motors
2880 props
two 22ah 8s packs
AUW 14kg
2016-08-16 14-09-08.bin (515.7 KB)
Man this reads like it is a beast 
Hope you didnt breake parts!
I am no log analysis expert and cant comment on the log nor can i give pid suggestions.
I i would try to strap the machine so it can hover but not crash into the ground for further testing.
Cheers
Beast is right. Normally the log would paint a good picture of what went on, but this is a little strange. You can see in the RC out and big oscillation. But no oscillation is recorded in the actual pitch and roll. It does show the unit tilting one way and then the other into the ground, but it doesn’t follow the RC out showing the oscillation.