IE Performance Downpipe For Audi B9 S4 & S5 3.0TMOTORSPORT SOUND IE's unique thick wall investment castings produce an aggressive, drone free exhaust note without the "tinny" sound typical on most full stainless body aftermarket options. Enjoy not only a louder exhaust but one with improved engine and turbo notes that will deliver miles of smiles. PERFECT FIT The B9 3. 0T hot v style engine has a unique center mounted turbo with a large downpipe that quickly splits into twin sided exhaust sections.