Power FC tuning IS overwhelming. It’s as user friendly as it can be, but engine tuning is not a user friendly process. Here is one of the many calcuations and coversions you will come across.
This pertains to the PIM values that PowerFC ominously hides your Boost Pressure as. They actually correlate to PSI.
Its VERY important to remember that 0 PSI in many cases is VACUUM not outside air pressure. We live on earth and there is 14.5 PSI of pressure at sea level ground. Damn gravity screwing up our calculations