Dinan D660-0079 Free Flow Axle-Back Exhaust System - BMW M5

The Dinan Free Flow Axle-Back Exhaust System transforms the BMW M5 (F90) with enhanced performance and an aggressive, sporty exhaust note. Engineered specifically for the 2018-2023 M5, this cat-back system delivers measurable power gains while maintaining the sophistication expected from a premium performance upgrade.

Performance Enhancements:

• Proven power increase of +6 HP at 6600 RPM and +5 lb-ft of torque at 6600 RPM
• Larger 83mm diameter piping compared to factory 80mm for improved exhaust flow
• Twin secondary exhaust valves feature massive 76mm diameter openings—30% less restrictive than OEM valves
• Reduces backpressure while optimizing exhaust scavenging

Premium Construction:

• 100% 304 stainless steel construction for corrosion resistance and durability
• Four massive 4-inch diameter double-walled exhaust tips with polished finish and laser-engraved Dinan logo
• Clamp-on tip design allows for easy adjustment and positioning
• Precision-engineered mandrel-bent tubing maintains consistent internal diameter

Intelligent Sound Management:

• Factory computer-controlled exhaust valves are fully retained and integrated
• Stock exhaust valve actuators are reused—no modifications to valve operation
• Exhaust tone adjustable through BMW's M-Drive settings just like the factory system
• Valves limit noise during low-speed cruising and open fully under high-load conditions
• Delivers a more aggressive, sporty sound without drone or excessive cabin noise

Installation:

• Direct bolt-on installation requires no cutting or permanent modifications
• All necessary mounting hardware included
• Replaces factory axle-back section from the mid-pipes back
• Professional installation recommended

This Dinan exhaust system provides the perfect balance of performance, sound, and refinement for the BMW M5. The retention of the factory valve system ensures you maintain complete control over exhaust character, from subdued and refined to aggressive and race-inspired, all at the touch of a button.