Audi S4 System

Billy Boat Performance Exhaust has once again taken the lead by designing a revolutionary exhaust system for the 2004 Audi S4. After months of R&D and custom-tuning, the engineers at Billy Boat Performance exhaust were able to create the perfect blend of performance and sound quality for the Audi S4. At any speed and RPM rang the B&B system emits a pleasing yet robust tone without annoying interior resonance.

Mandrel bent from T-304 stainless steel, the S4 exhaust system is a "manifold-back" true dual system and includes two down pipes, a center resonator section, and two rear mufflers. The Billy Boat Performance Exhaust system for the 2004 Audi S4 is completely hand-crafted, TIG welded, and features integrated flex joints and high-flow catalytic converters in the down pipes. Installation is simplified with the use of 3/8" thick flanges and machined billet hangers that mount in the factory hanging locations. This exhaust system is a completely bolt-on performance modification that does not require any cutting or welding for an easy installation!

This Billy Boat Performance Exhaust system enhances and blends with the styling of the 2004 Audi S4 with fully-polished mufflers and 3.5" fully polished double wall tips.