Semi-Active Muffler Valve (5.0L Supercharger Vehicles Only)
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The semi-active muffler valve is operated by the pressure in the exhaust system. At low engine speeds the valve head is closed or partially closed to provide a more refined noise quality. At higher engine speeds the increased pressure within the exhaust system opens the valve head to provide a more sporting noise. This is achieved by the valve, which once open, allows the exhaust gasses to by-pass the baffle tubes and plates in the rear silencer.