Dinan Valved Axle-Back Exhaust System with Polished Tips for BMW M3 / M4 2021-2025

The Dinan Valved Axle-Back Exhaust System for the BMW G8x M3/M4 is designed to address the well-documented sound limitations of the S58 engine. While the G8x chassis offers improvements over its predecessor, the exhaust note can often fall short of the performance image the vehicle projects. Dinan’s exhaust system solves this by delivering a deeper, more refined tone while enhancing overall performance, offering flexibility between quiet operation and aggressive exhaust notes depending on driving conditions.

Key Features:

• Performance Gains:

  • Achieves +6 HP and +5 lb-ft of torque at maximum gains, contributing to increased power output.

• Improved Sound:

  • The valved design allows for louder, sportier sound during aggressive driving while maintaining a more subdued note during low-speed operation.
  • The system also incorporates drone abatement technologies to reduce cabin resonance, ensuring a more pleasant experience inside the car even with the enhanced exhaust note.

• Advanced Flow Dynamics:

  • Larger diameter piping (76mm vs. 70mm stock) improves exhaust flow and reduces backpressure, enabling more efficient performance throughout the system.
  • When the factory valves are closed, exhaust gases pass through the Dinan muffler, producing a deeper and quieter tone. When the valves are open, gases bypass the muffler entirely, delivering a near straight-pipe design for maximum sound output during spirited driving.

• Enhanced Appearance:

  • The system features quad 4.5-inch (114mm) double-walled polished stainless steel clamp-on tips, which are laser-engraved with the Dinan logo. These massive exhaust tips provide a commanding presence that fills the factory diffuser cut-outs perfectly, enhancing the vehicle’s rear-end aesthetics.

• Weight Reduction:

  • Weighing 6 pounds lighter than the stock axle-back exhaust (Dinan: 38 lbs vs. Stock: 44 lbs), this system offers a performance gain without adding excess weight.

• Durable Construction:

  • Made from 100% T304 stainless steel, the exhaust system is TIG welded for superior durability and corrosion resistance. The entire system is brush finished for a clean, immaculate appearance.

• Factory Valve Integration:

  • The system retains the factory exhaust valve actuators, so the vehicle's M-drive settings can continue to control the exhaust tone. This allows for precise customization of the exhaust note based on driving preferences, from subtle to aggressive.