Valvetronic Designs Audi RSQ8/Porsche Cayenne/Lamborghini Urus 400 Cell Catted Downpipes

The 4.0T twin-turbo V8 powering the Audi RSQ8, SQ8, and SQ7 delivers immense performance — but factory catalyst restrictions hold it back. Our NEW EPA-compliant 400 cell high-flow catted downpipes are engineered to increase exhaust flow, enhance turbo efficiency, and dramatically sharpen the vehicle’s sound profile — all while maintaining emissions compliance standards.

This is the foundation of true 4.0T performance.

Why Upgrade to 400 Cell?

• EPA-Compliant 400 Cell High-Flow Catalysts: Increased exhaust velocity while maintaining compliance standards.
• Faster Turbo Spool: Reduced backpressure improves throttle response and mid-range torque delivery.
• Sharper Exhaust Note: Enhanced turbo acoustics with deeper low-end presence and more aggressive top-end tone.
• Optimized Performance Balance: Noticeable gains without compromising daily drivability.

Performance & Engineering

• Optimized Flow Architecture: Designed to reduce restriction while preserving catalyst efficiency.
• Mandrel-Bent Tubing: Smooth internal transitions for maximum airflow.
• Precision TIG Welding: Built to withstand extreme exhaust temperatures and boost pressures.
• Direct OEM Bolt-On Design: Utilizes factory mounting locations for straightforward installation.
• Engineered to Pair Seamlessly with Valvetronic Titanium Exhaust Systems

Sound Transformation

• Stock Exhaust + Downpipes: Noticeably louder with stronger turbo character and deeper exhaust tone.
• Valvetronic Exhaust + Downpipes: Maximum transformation — sharper transitions, increased aggression, and a true RS-inspired exhaust signature.

Construction & Durability

• Premium high-grade stainless steel construction
• High-temperature resistant 400 cell catalyst cores
• OEM-style sensor placement for proper operation
• Engineered for long-term reliability under high boost