US Patent 7549512 Muffler for internal combustion engine

The improved muffler design has a housing that is hexagonal in shape that is formed from an upper plate, a lower plate and sidewalls that form a perimeter around the housing. An inlet and outlet are attached to opposite sides of the housing along the length. A primary vein is mounted within the housing with that allows some of the gases to around the vein and some of the gases to flow through holes in the leading surface of the primary vein. A secondary vein is mounted downstream of the primary vein and a mixing vein is mounted downstream of the secondary vein. The widest point more of the housing is closer to the than the outlet so the housing resembles a coffin.