FREE $50 King Motorsports Gift Card with Purchase! As with all Mugen systems, the 8th Gen Coupe setup is perfect in fit, finish, sound and performance. All stainless steel construction, perfect mandrel bends and finished with a polished tip with the Mugen logo laser etched into it. The piping is 60mm and both the front silencer and unique 3-sided rear muffler are perfectly constructed from stainless steel. And the sound is all Mugen - deep and throaty when you're on the throttle, mellow at cruising speed. No droning or rasping, just that signature Mugen tone.