Intake = useless part, pluck it out for slightly quicker and smoother turbo spool
Resonator = if you pull it out, it'll be VERY loud w/o much performance gains

 

A resonator is in the exahust .. your stock exhaust system has one to help the muffler out with reducing noise. the little round thing you throw into your exahust tip is a silencer. In the intake it would be correct to refer to it as a silencer or a resonator.

 

i chopped mine off with a hack saw so I cuold keep the stock look. It sounds cool but i can't say that i noticed any gains from it. Make sure you keep your filter clean or replace it more often because it sucks in all sorts of crap from the fender. I get a bunch of clutch dust on mine.

 

if you want to hear your turbo more throw a catless downpipe on there =)

 

Silencer (AKA Snorkus):



Resonator:



I've removed the silencer on all of my Subarus with no problems. It's just to make the intake quieter. I can't see how it can't be a restriction although I can't say it makes a huge difference. If you remove the silencer and open up the gasket in the airbox you will get a larger air intake from the fender. This pic was on my RS but it's the same for others too:


This has 5.73 sq/in of open area :



This has 9.6 Sq/in:





AKA restriction

Peaty

PS: With the silencer removed it will also grab cold air because the front part will get heat soaked during traffic (the intake part under the hood to the radiator) but I don't want to debate if cold air is good for a turbo or not. The fender air remains cold I've measured it.

 

Once Peaty saves the day! Thanks for the pics and info