APR Catback Exhaust System - RS4 / RS5 (B9) - CBK0037

Introducing the APR Catback Exhaust System for the Audi B9 RS4 and RS5

The APR Catback Exhaust System for the Audi B9 RS4 and RS5 is a complete, high-performance exhaust solution that runs the entire length of the vehicle from the catalyst back. This system is engineered to boost performance, elevate sound, and enhance aesthetics with RS-style diamond black oval exhaust tips that are sure to make a statement. Crafted from premium materials and built with advanced manufacturing techniques, this system is designed to withstand harsh conditions and deliver lasting performance. Expect a bold, aggressive growl at wide-open throttle, along with an impressive gain of 9 horsepower and 15 FT-LBS of torque to all four wheels!

Unmatched Design and Precision Engineering

Unlike anything currently available, the APR system includes downpipes extending to the factory catalyst in the upper engine bay, making this a true full-system upgrade. We’ve minimized restrictions with smooth transitions, oversized piping, and straight-through mufflers and resonators. Constructed from mandrel-bent T304 stainless steel with a brushed finish and TIG welding throughout, this exhaust system is as durable as it is striking. Installation is hassle-free, thanks to precision-fit brackets, OEM-style slip clamps, and an included upgraded tunnel brace to accommodate the oversized piping.

Inspired by RS Performance

Like the RS4 and RS5, this system stays with the unique single oversized midpipe design. It utilizes dual 2.75” (70mm) downpipes and midpipes that merge through a cast Y-junction into a massive 3.5” (91mm) midpipe. The integrated Helmholtz resonator minimizes drone through a straight-through design with a sound-canceling port, ensuring no compromise in exhaust flow.

The system splits again via another cast Y into two rear, valve-controlled mufflers with sound absorption technology. These valves are fully integrated with the OEM control system, adjusting automatically to enhance sound during aggressive driving while maintaining a quieter profile during cruising. Finally, exhaust gases exit through dual cast Y-junctions into a quad 2.5” (63.5mm) system, terminating via oversized 7.25”x5” RS-style exhaust tips. The tips feature a diamond black finish and a subtle APR logo for a refined touch.

Experience the APR Difference

Designed for enthusiasts seeking the perfect balance of power, sound, style, and quality, the APR Catback Exhaust System for the Audi B9 RS4 and RS5 is a testament to engineering excellence. With its performance-driven design and durable construction, this system not only transforms your driving experience but also ensures years of reliable performance.

Features & Benefits

• Complete catalyst-back system including downpipes, extending from the factory catalyst back.
• Dual 7.25”x5” RS-style diamond black oval tips with APR logo.
• Smooth transitions and straight-through components maximize performance by reducing restrictions.
• Strikes the perfect balance of power, sound, style, and quality for enthusiasts.
• Fully emissions compliant for worry-free operation.
• Performance gains of 9 HP and 15 FT-LBS of torque delivered to all four wheels.
• Premium T304 stainless steel construction with TIG welding for strength and durability.
• Optimized flow through dual 2.75” downpipes, 3.5” midpipe, and quad 2.5” exits.
• Mandrel-bent brushed piping paired with electropolished cast splitters for a refined finish.
• Precision brackets and slip clamps ensure accurate alignment and hassle-free installation.
• Includes an upgraded tunnel brace to accommodate the larger piping.
• Integrated Helmholtz resonator minimizes drone and enhances sound quality.
• Valve-controlled rear mufflers dynamically adjust sound based on driving style.