i'd only use pod filters if they r fed air of similar or cooler temperatures than the original (ie. cold air intake feed)
otherwise sticking a pod filter in a hot engine bay gives zero/negative gain and is very bad during standstill where it sucks in the hot trapped air.
an alternative is to replace the current stock with a k&n panel filter and then increase the intake pipe upto 70mm whilst also routing it to a cold air source.
the hose from the air filter to the top cam cover is the PCV breather. its job is to supply filtered air into the engine so that when the throttle is closed, the high vacuum sucks air from the air filter, through the engine crankcase collecting any nasty vapours, through the one way PCV valve and into the combustion chambers to be burnt.
