The Power FC has an optional boost controller kit that allows the PowerFC to manage the wastegate and ultimately the boost level.
This kit comes with:
a 3 bar boost sensor that is plug and play
a wastegate solenoid
Remove the hose and wire from the stock MAP (Manifold Air Pressure) sensor. Plug both into the new 3 Bar MAP sensor. This is plug and play.
The old sensor can be used with the supplied 3 or 5 pin wire. It is supposed to sense elevation changes and be a redundant boost sensor up to 15 PSI. Not necessary. This wire will plug into the side of the PowerFC main box next to the commander plug.
The wastegate solenoid plugs right into the stock wastegate plug. If you have modified your car and eliminated the wastegate wire, you hopefully have spare wire pins to rewire it back into the PowerFC.
Turn the key but dont start your car. You must make some changes to the PowerFC for the wastegate solenoid. The boost levels will have two numbers (for the stock twin turbo system) you will only look at the primary setting.
Go to the ETC menu and go to functions. Disable sequential turbo function.
Go to MAP (may be called PIM) sensor menu and choose option 1 instead of normal. If you don’t do this, the car will not want to start and will be very unwilling to run.
(Paraphrased from Rotaryextreme on rx7club.com)