Branching off from another thread.
And some discussion here too, with several examples:
Here's a great way to analyze a dyno plot.
BMEP (in psi) and BMEP per MAP in psi per atmosphere of MAP
BMEP (in psi) = tq (ft-lbs) / displacement (L) * 2.47
BMEP per MAP = BMEP / MAP (in atmosheres)
BMEP per MAP = BMEP / MAP *101 (if MAP is in kPa)
The magic number is 180 psi at torque peak.
This translates to 73 ft-lbs per L per atmo of MAP.
Here's the importance of BMEP
The resulting BMEP/MAP is an indication of VE and correct ignition timing.
In my curve above, the plot from 4000-7000 is VE
The reduced VE below 4000 RPM is due to the the wastegate being closed, TIP is higher to accelerate the turbo shaft.