maximum is -mx ld1600m, you could have figured that out yourself by opening up freearc.

i remake the arc with this compression and i included the manual's folder to the installation folder for more compression and replace gfwl with the live setup

Installations works fine and the final size is 4,36gb but i have a problem: the dirt3_game.exe isn't the same in the complete edition and the game no works, i don't know how to replace it

just add in an extra folder before burning it, then after installing replace the exe with the one that works for the game you have.