load measurement

I'm going from n/a to boosted application. Obviously myload values/axis' are going to need modifying. my quesion is this, How do I calculate which load values to populate the axis' up to the ceiling ? Not clear on the technical difference between engine load and air load. I know what air load is and understand the simple math to calculate it but how to populate my axis', which tables or is there one app in the tune that is more prevalent than others to apply these changes. I'm using hptuners with current software on a 2007 mustang gt with spanish oak ecm on a somewhat frankenstein build

The amount you'll need to extend the load axis will be very dependent on how much air you're intending to move. It isn't actually that critical though and you can take a bit of a guess at where you think you'll end up and then adjust the scaling to suit once you're up and running and you can see what the actual measured load is. As a really rough approximation though if you took a stock N/A engine and added 15 psi of boost you can expect to be broadly around double the measured load.

will be running street tune at or around 18-20 psi and track duty will see 28-30psi on c16