Are you using the remote map selector? Make sure both maps show up the same on your dashboard when you are tuning, the first time mine was tuned, somehow they were reading differently and we weren't adjsuting the map we thought was operating, but were going by the switch indicator. Kept opening up the ABC as well with no effect. Once we saw the discrepancy and figured we were adjusting the wrong map, it was obvious why boost wasn't increasing.
I have an 04 STI and had to use the ABC to make the boost I wanted, but went as high as 21-22 psi on race gas. My ABC needed 3 turns open and values across the board of 500 to do it.