I know that the same problem was already discussed here, but i din't really find the solution.
drumex suggested this

Quote from drumex :

Here's how I used to do this:
press the calibrate button while the joystick is in center position, and pull it back all the way through, and return it to center. This should map the center-to-bottom travel as 0-100% for that axis. Then lock the axes.
Hope that helps.

but i can't calibrate it this way, it's all the same at a half brake because of it's center position.
Maybe someone succeed in calibrating the joystick and can explain calibrating process properly?

You should unlock youre axes in lfs, turn youre wheel from side to side, and depress each pedal, one at a time. Then do NOT push forwards on the joystick, only pull it from center to back, and back to center, and lock the axes again.

Now LFS should know, that the movement from center to fully back is 100% movement

Quote from neRu :

You should unlock youre axes in lfs, turn youre wheel from side to side, and depress each pedal, one at a time. Then do NOT push forwards on the joystick, only pull it from center to back, and back to center, and lock the axes again.

Now LFS should know, that the movement from center to fully back is 100% movement

Thanks! It worked.