Ajayjay: Post the part number of your stock
ecu and i'll tell you what you have.
Jester: Every powerFC has a 3 pin header on the side of the
ecu, not many people realise this is to allow you to run a 3 bar map sensor. A standard 3 bar (3 pin) Delco map sensor can be used to overcome the oem 2 bar subaru map sensor issue.....cheap fix for big boost.
Here are some of the AFM spec's for different Nissan afm's that are compatible with the FC:
80mm VG30 airflow meter can measure up to approx. 500ps (368kW)
90mm VH41 airflow meter can measure up to approx. 400ps (294kW)
So with a map sensor swap and an afm swap the numbers can be as large as your budget will allow!