My WRX has standard intake atm, but a few people have told me to do away with the original airbox and opt for a cone filter/induction kit with heat shield. Anyone else running aftermarket filters and would you recommend them? My previous car was an astra VXR and you couldn't hear the turbo on that much, but when I fitted a pipercross open cone it sounded incredible! Could really hear the turbo spooling up and dumping!

Most people will say it's not needed unless you want to push the 400BHP as the OEM will do fine. Me I'm not most people so have a K&N one :) can't say I see any massive gains from it as it was fitted at the same time as the engine rebuild and map. But I always like the thought it can get enough air at all times :)

http://www.knfilters.co.uk/search/product.aspx?Prod=57A-6018

I have this one can be found cheaper on ebay now. And some tool when it was in the garage has lost my air pipe going to it but seen I can get a ramair one cheap enough :)

As Gambit says the change to a standard engine is not that significant - you will probably get more noise dependant on type but you could get improvements by increasing the size of the induction channel on the other side of the filter and retain the standard airbox but with a hi flow panel instead of stock

Gambit, got any pictures of it fitted and does it give a good induction sound? I can get a 57i Kit pretty cheap from my local parts specialist although they only really help for extra noise lol

I can sort you a picture out mate that's not a problem. As for the sound I think I get more from the exhaust and DV to notice :D