Dinan Free Flow Axle-Back Exhaust - 2001-2006 BMW M3 Wheels A vacuum controlled butterfly valve

A vacuum controlled butterfly valve is utilized to improve flow at wide-open throttle while keeping things civilized and 'drone' free throughout

With different shapes

This allows exhaust gases to exit the turbine more efficiently and reduces backpressure on the turbine side

smoother and fuller exhaust note

this system is designed to provide a more aggressive sound under acceleration

Dinan Free Flow Axle-Back Exhaust - 2001-2006 BMW M3 Wheels A vacuum controlled butterfly valveIf you've been searching for a truly high performance Axle Back exhaust for your M3 look no further. Dinan's unique muffler design effectively reduces back pressure for improved flow, resulting in measurable power gains. Manufactured from 304 stainless steel inside and out for superior resistance to corrosion as well as a significant reduction of weight. And from those aggressive looking ceramic coated tips flows an exhaust note that will be music to