When I had my 2014 4/4 remapped by Cain and including a K+N filter in standard airbox it produced 14bhp increase as measured on rolling road.

Next increase to 136 bhp was fitting of Librands tubular manifold and sports exhaust.

" I LOVE THE SOUND OF THROTTLE BODIES IN THE MORNING " (ROBERT DUVAL IN "APOCOLYPSE NOW " )