Audi B9 S4 Milltek Catback Exhaust Sound (vs. Stock) 

Milltek Catback Exhausts: goo.gl/7k6yEf
Milltek Downpipe: goo.gl/bU2ecb
Carbon Fiber Body Accents: goo.gl/4gRJdQ
In this video we compare the stock Audi B9 S4 exhaust sound with a Milltek non-resonated catback system. All clips were filmed in Dynamic drive mode, which keeps the exhaust valves open.
This catback exhaust system is manufactured of a 2.50" T304 anti-magnetic stainless steel that is less susceptible to discolouration when compared to other systems found on the market. This quality T304 stainless steel is used on all of the pipework including the construction of the mufflers and resonators. Mandrel bending ensures full flow bends for better exhaust gas flow and Milltek systems are increased in bore to ensure the ultimate performance without the loss of mid-range torque. This exhaust allows you to retain the use of the factory exhaust valve system.
The valved mufflers reuse the factory valves from the OE system and seamlessly integrates into the car's vacuum system without any modification. The valve system is operated like stock through the Drive Select options.