Abstract: The device for producing an overtone-rich, sporty exhaust sound of the exhaust system of a four-cylinder engine includes exhaust pipes with four manifold pipes, at least one front pipe and a tail pipe. The length and/or cross-section of at least one exhaust pipe differ from the length and/or cross-section of the other exhaust pipes. At least some of the exhaust pipes lead into a first, second and/or third collecting point.

Abstract: A flange for attaching an exhaust manifold to an engine block. The flange having two layers of sheet metal plates accurately connected to each other and having openings which are aligned with the cylinder outlets of the engine block, and attachment openings which are placed on stay bolts on the engine block. The flange includes at least two flange portions, whereby the plates of adjacent flange portions overlap in the area at least of one attachment opening. The contact surfaces can have a slide coating in the overlap area.

Abstract: A muffler having a movable valve disk, with the help of which at least one of the tubes in the muffler housing can be opened and closed. The actuation organ for the valve disk is a corrugated tube, the fixed end of which is placed into an opening in the housing and the interior of which is connected to the atmosphere. As a result, the total pressure loss of the muffler is available as an actuation force.

Abstract: A muffler and an actuating cell provided so that the acoustic properties of the muffler can be changed. The pressure drop in the muffler is fed to the actuating cell as a control pressure. The actuating cell has a plurality of chambers which are separated by diaphragms. Each diaphragm is supported by a spring and each chamber has a pressure connection. A first pressure line feeds the total gas pressure to the overpressure side of the first diaphragm. Another pressure line directs the static gas pressure to the low-pressure side of this diaphragm. Attached to the diaphragm is a piston rod which carries a valve closing element which closes or opens a gas feed pipe.

Abstract: A muffler having an inner shell of two deep-drawn inner sheet metal plates laid one atop the other and a housing shell of at least two deep-drawn outer sheet metal plates laid one atop the other. The inner shell has an encircling edge while the housing shell has an encircling housing flange with a lock seam connection which seals the housing shell. The edge of the inner shell is designed so that it barely touches the wall of the housing shell and is held in a spring-like fashion only between clamping creases of the housing shell.