Automotive exhaust system

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of an exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter than the diameter of the exhaust pipe, comprising:

• a uniform diameter pipe having a diameter approximately that of the exhaust pipe for conventional muffling extending from the engine exhaust manifold to an opening to the atmosphere, the pipe carrying within exhaust gases from the engine to the atmosphere;
• and
• a plurality of porous metal filters having a webbing and openings therebetween positioned within the pipe along its length to muffle the noise of the exhaust, said filters being formed of at least one elongate strip element of expanded metal, said element being folded at preselected positions along its length to form individual filters between the folds, adjacent filters being separated by the folds, selected ones of said filters having webbing coated with alumina and a platinum group metal to perform a catalytic conversion function, said element being of uniform width and defining filters of rectangular cross section upon folding to form four arcuate channels between the inner wall of said pipe and edges of said filters to further attenuate sonic frequency shock waves, the openings between the webbing of said filters being approximately 1/4 by 1/8 inch.

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of a conventional exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter than the diameter of the exhaust pipe, the vehicle being specifically constructed to mount an exhaust pipe of said diameter, comprising:

• a uniform diameter single walled pipe having a diameter no greater than approximately that of the conventional exhaust pipe, said uniform diameter pipe extending from the engine exhaust manifold to an opening to the atmosphere, the uniform diameter pipe carrying within exhaust gases;
• muffling means within the uniform diameter pipe for muffling the exhaust, the muffling means extending continuously along the entire length of the uniform diameter pipe so that the entire length of the uniform diameter pipe has a muffling effect on the exhaust;
• and
• the single walled uniform diameter pipe being sized to fit in the vehicle without redesign of the vehicle configuration as a result of the uniformity between the outer diameter of the uniform diameter pipe and the conventional exhaust pipe.