you still will probably need an fmu with that ammount of boost. The FMU uses boost pressure to determine how much psi of fuel should be in the injectors accordingly.
i would say you need the fmu. i am running a s-trim at 12lbs of boost. i have a 255 in tank, and a external t-rex with 42lb injectors. i had to run the fmu with 3:1 disk to keep my air/fuel at 11.7 across the board.