The D-Jetro Power FC units carry the same functions as the regular Power FC units but do not require the use of the factory standard air flow meter and use a mass air pressure sensor. Apart from the unit itself, use of the D-Jetro units requires additional parts that vary depending on the model." -
http://www.greenline.jp The airflow meter (at least in the skyline range) does not pose a big restriction in terms of horsepower and one would doubt the use of the D-Jetro. If you really need massive airflow you can always change to 2 x Q45 Airflow meters and use those with the PowerFC. The skyline series are optimized for closed loop operation with an airflow meter.
The Djetro version has a few caveats you should know about before you consider using it
Careful placement of the map sensors in multiple throttle body systems With multiple throttle bodies, such as the Skyline GTR RB26 or the Pulsar's GTI-R SR20 multiple throttle bodies can have bad side affects when using a map sensor system. Consideration needs to be taken into account when placing the map sensor (or map sensors) for the Djetro system to avoid idle problems on multiple throttle bodied engines.
Tuning will take considerably longer It will take considerably longer to tune a Djetro PFC over a normal LJetro PFC. This is because all of the work has to be done from scratch instead of just doing the main bits in the AFM/LJetro version. You should discuss this with your tuner and find out the total cost for a Djetro tune.
There is an Apexi FAQ under general tehnical
