The intake manifold dead duck historically been manufactured from aluminum or cast robust but call of composite plastic materials is gaining popularity (e.g

Variable Length Intake Manifold (VLIM) is an enclosed combustion engine manifold technology. Four banal implementations exist. First, two discrete intake runners with different length are employed, and a butterfly valve can close the curtailed path. Second the intake runners can be bent around a common plenum, and a sliding valve separates them from the plenum with a variable length. Straight high-speed runners can receive plugs, which Headers contain immature long runner extensions.