What is it?
Registered User
Joined: Jan 2005
Posts: 808
Likes: 0
From: Canada
there is a ring just inside the inlet of your turbo, when you take off the tube that clamps to the turbo, where it comes from the air box.you will see a trim ring like band inside the opening, held in by a c clip.doesn't do anything for power, just makes a little more noise,or whistle when on boost.