EP-Azz

hi all, was chatting the other day with the old man and he cant see how the car can make more power as in an extra 40 or 50 brake with the standard management? for intance mine has a hdi intercooler,zep decat, blitz nur spec, ctt9/ct12/ct20 hybrid, zisco mani w/ screamer,monster motorsport relocation, apexi cone filter,magnecor leads , and keirz says its been dynoed at 174bhp on standard management so how does the ecu know what mods are on it in order to make more power and safely?