BMW power kit is
Auxiliary Water Cooler (including air ducting)
Enhanced Radiator Fan
Gives 320bhp and 332lb/ft.
No reason why you couldnt stack a JB4 ontop of this to run the aquamist meth kit and up the boost rather than get a custom map... JB4 has the failsafes built in too.
Catless downpipes are where the real power/torque is to be found.
Car: 2010 Jaguar XFR (Stock - For now)
Gone but not forgotten: Highly Modified E90 335i LCI M Sport Manual (circa 480BHP/500lb ft)