Redstar Audi B9 S4|S5 Downpipe

Description

Unleash the performance of your 2017+ Audi S4 B9/B9.5 3.0t Turbo and 2017+ Audi S5 B9/B9.5 3.0t Turbo with Redstar performance exhaust downpipes. Developed with an expansive bore and flow-optimised transitions for superior gas velocity and efficiency, these downpipes replace the restrictive factory sections to let the 3.0T breathe freely and respond harder.

By lowering backpressure you will feel quicker turbo spool, sharper throttle response and real gains in usable power, all accompanied by a deeper, more engaging tone. Choose Redstar's OEM-style heat shielding option with a ceramic inner liner to cut radiant exhaust heat by up to 80%, helping control under-bonnet temperatures and supporting turbo life during demanding use.

Built for durability and seamless fitment, every system uses 2.0mm wall 304L stainless steel, is 100% TIG welded and back purged, and integrates with OEM-spec V-band flanges and factory-style brackets for a true bolt-on upgrade. Tailor the package with GESI GEN2 400cpsi catalytic converters rated to support up to 1000hp for smoother flow than stock and refined operation. Precision engineering, robust manufacturing and unmistakable Redstar sound make this the ideal foundation for extracting more from your Audi S4 or S5.

Available Options

• GESI GEN2 400cpsi Catalytic Converters: The latest GEN2 series from GESI is rated to support up to 1000hp while offering smoother exhaust flow and improved efficiency compared with factory units. Featuring advanced emissions technology for optimal catalyst function at high flow rates. A strong choice for those seeking significant performance gains with refined operation.
• OEM-Style Heat Shielding: Redstar's signature thermal management system reduces radiant exhaust heat by up to 80%. Developed with motorsport-inspired materials and construction, it uses a multi-layer design of ceramic insulation and embossed stainless steel foil. Unlike wraps or coatings that degrade quickly, Redstar shielding delivers long-term durability and consistent protection for engine bay components.

Key Performance Benefits

• Noticeable power and torque gains from reduced backpressure and improved flow
• Faster turbo spool and sharper throttle response
• Lower under-bonnet temperatures with optional heat shielding to help protect components and support turbo longevity
• Deeper, more engaging exhaust tone
• 100% bolt-on installation using factory mounting points

Technical Specifications

• Highest quality 2.0mm wall 304L stainless steel
• 100% TIG welded and back purged
• OEM-spec V-band flanges
• All brackets and mounts as on OEM unit

Fitment

• 2017+ Audi S4 B9/B9.5 3.0t Turbo
• 2017+ Audi S5 B9/B9.5 3.0t Turbo