Transverse partition for exhaust volume

A transverse partition for separating an exhaust volume into two adjacent chambers, the partition being of the type comprising at least one passage for allowing gas to flow between the two chambers, the gas flow section through the passage being modifiable under drive from the difference between the pressures on the two sides of the partition, the partition comprising a wall pierced by at least one slit defined between two adjacent edges of the wall, which wall is elastically deformable under drive from the pressure difference between the two sides of the partition, between a rest position in which wall continuity is ensured, the two edges of the slit being substantially touching, and a deformed position in which the two edges of the slit are spaced apart so as to define said gas flow passage between them,

• wherein the thickness of the region of the wall in which the slit is defined is greater than the average thickness of said partition.