k&n typhoon will work fine untuned. but im gonna tell you from experience that if u want to go to a bigger turbo etc then sell your intake now. first for you to be thinking of dp/catback etc is way far ahead of yourself and im not trying to be dick. AND LEARN TO USE UR DCCD ON TURNS DO NOT OVER DO IT ON TURNS OR U WILL BE LIKE THE MANY OTHERS WITH A WRECKED STI. i can not emphasize this more learn to drive your car. but also what car are u upgrading from?