Had some trouble with a Quad setup as follows:
4x U8 135 KV
4x 29x9,5 ( 3 blade props)
4x Flame 80 ESC
With help from Leonard the new tuning produced some interesting PIDs (way off the scale) but it seems to work.
I have attached the parameter file for anyone having issues with tuning such large quads.
Forgot to mention battery is 6cells