Tuned manifold

摘要

A manifold for a bank of four cylinders of an engine comprises four primary tracts each leading to a respective cylinder, and two secondary tracts each connected at a respective one of two branching points to a respective pair of primary tracts which lead to cylinders of which the combustion cycles are in antiphase. The two branching points are arranged contiguous to one another to form a decoupling chamber between which there is disposed a valve connecting the two branching points. The resonant frequency of the manifold can be changed by opening and closing the valve.