Unleash the potential of your BMW X5M F85 and X6M F86 with Redstar performance exhaust downpipes engineered specifically for the S63B44 4.4 V8 Bi-Turbo. Developed for 2015-2019 models, this system replaces the factory downpipe section with a precision-built, bolt-on upgrade designed to integrate with OEM mounting points.

Expect faster spool, sharper throttle response and a noticeable uplift in power, alongside a richer, more engaging exhaust tone. Choose from high-performance catalytic options including HJS HD 200cpsi and GESI GEN2 400cpsi converters rated to support up to 1000hp, both aimed at improving flow over the stock setup. RedstarÕs OEM-style heat shielding with a ceramic inner liner draws on motorsport practice to reduce radiant heat by up to 80%, helping to curb under-bonnet temperatures and support turbo longevity.

Built for durability and accuracy, every assembly is 100% TIG welded and back purged from 2.0mm wall 304 stainless steel, using OEM-spec flanges with factory-style brackets and mounts. The result is a true bolt-on Redstar downpipe solution for the BMW X5M F85 and BMW X6M F86 that blends engineering focus with real-world performance gains.

Available Options

• HJS HD 200cpsi Catalytic Converters: Engineered in Germany and trusted worldwide, the HJS 200cpsi ultra high-performance cats are rated for over 1000hp. Renowned for exceptional flow, durability, and consistent quality, these converters set the benchmark for high-output applications. Ideal for drivers demanding maximum performance without compromise.
• 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 increase in power and torque
• Quicker turbo spool and sharper throttle response
• Helps extend turbocharger service life
• Lower under-bonnet temperatures for improved thermal control
• More engaging, refined exhaust tone
• True bolt-on installation to factory mounting points

Technical Specifications

• Fabricated from 2.0mm wall 304 stainless steel
• 100% TIG welded and back purged for precision and strength
• OEM-spec flanges for secure, leak-free sealing
• Factory-style brackets and mounts for OE-level fitment

Notes

• Euro 6 compliant when optioned with HJS HD 200cpsi catalytic converters

Fitments

• 2015-2019 BMW X5M F85 S63B44 4.4 V8 Bi-Turbo
• 2015-2019 BMW X6M F86 S63B44 4.4 V8 Bi-Turbo