Since I downloaded toribash 3.9 beta8, I detected a little change In the psychics mechanic and a little speed up on the movements.

It changed or im seeing things?

donno but the 3.91 is out so i suggest u download that instead
after all beta is called beta because it's still in testing or incomplete

Thank you, but thats not the answer that I want.

I noticed this when we updated from 2.4 to like 2.5 pr w/e

2.0 seemed to go mega slow and the characters seemed to be really bulky and weighted down

There has been no change since like, 1.9 or something to the physics.
It's probably just a slight change in the speed at which your machine runs the game.