I don't get on here much these days... Don't find a lot of time at all at the moment
Problems with this are the variables.... aside from individual setups, mods etc. and the occasional freak of nature setup that just makes power for no known reason.....
Longeivity - push it hard, it'll go bang.
Engine compression - higher compression lumps like the BWA can make more power if you can contain the knock and likelihood of terminal piston/rod bending/melting and/or ejecting. Seen a Built (properly - Forged)BWA K04 be pushed to over 400hp after fiddling with knock control just to see what is possible. Meth or race fuel dependant....different ballgame
Air density (pressure/temperature/IC efficiency) and knock supression/quality of fuel play the next biggest factors in determining any peak value after you have reached the airflow ceiling. Race fuel and/or the help of N2O will surpass the 400hp mark by quite a margin, as measured in the way predominantly used in this country using coastdown measuring etc.
Measuring on a bench is a different ballgame and is just changing the goalposts to be honest. No aftermarket tuner bench tests these for numbers. Then again adding N2O and race fuel is also changing the goalposts.
My two pence