Quote Originally Posted by TypeG View Post
it is all about your budget and target

CAI like injen give u a loud noise over 4000rpm and got great improve on high end but lag on low end.
Drop in filter like K&N gave you slightly more airflow but dont expect much
Airbox replacement like Mugen and Icebox give u improve on high,mid and low end but wont have so much high end like Injen
Spot on!