i managed to solve it.. after i posted, i remebered that also the previous esc were calibrated with my previos fc, a kk board.. for some reason i couldn't calibrate correctly directly connected to receiver...
so i connected my 4 new escs to kk board and did throttle calibration. Once connected to Paris board, everything was fine.
I am not using ppm sum, using Y cable to drive 2 esc from 1 output, board thinks it's a quad, so i can still use camera stabilization outputs.
Managed to make a quick flight before it started raining again..
It seems to fly ok, but i thought it would have more power. hovering at 60% , just like it did before when it had only 4 motors... so i actually gained nothing by adding 4 motors. I need to do more tests, try to invert props/motors etc..
Upper motors keda 2022L with 10x3.8SF
Lower motors turnigy 2209 1050Kv with Gaui 8" props.
2 x 3300 3s turnigy
Fiberglass reinforced balsa central backbone with 15mm alu arms.
i only have a mobile phone pic...
wiring still needs to be cleaned.. wow there is a lot of it on a 8 motor config with 2 batts and 2 separate power boards...