The PCV valve puts vacuum (from inlet of supercharger) to the crankcase. The crankcase now needs and air source (crankcase is sealed and vacuum is bad) so there is a hole in front of LIM. This hole let's air into crankcase. The passage connect through the supercharger up-through the throttle body (gen 3) and gets air from after the MAF and before the throttle plate. The air is measured by the MAF so the computer sees all air for combustion.