So you have A LOT of unknown variables to be able to say its valving. Im not saying you're wrong, but to give an educated guess, more information is needed.going thru one corner with 180 km/h and front go unstable , and after i change the pistons go thru the same corner with 200 km/h without front go unstable .
What U think ? For me this will give more fast REB (hi and low) and more fast HI COMP .
What problem are you actually trying to fix? Is the front end moving in the corner like you stated?
If so, what part of the corner (enter, mid, exit)?
Are you on the brakes or off?
If on the brakes how hard?
Are you on the throttle or off?
If on the throttle, how far into it?
What springs are in your forks?
How much preload?
Where were your comp and reb at before you changed to Bitubo?
How much trail do you have?
Spring rate and preload?
Comp and reb on shock?
Swing arm angle?
While the vavling seems to be helping, it may not the actual underlying issue. Knowing the whole story will allow one to make a better guess to what direction to go.