A supercharger assembly comprises a housing, a rotor bore with an outer wall, an outlet in an outlet plane, an inlet in an inlet plane perpendicular to the outlet plane, and an outlet divider wall. The supercharger assembly comprises a first recess, a first perforated material covering the first recess, and an outlet resonator. The first recess is separated from the outlet by the outlet divider wall. The first recess is located between the outer wall and the first perforated material.

An air induction system for a vehicle internal combustion engine has an air filter box that couples with the internal combustion engine. A tuner, in the air filter box, removes offending lower frequency noise generated by the internal combustion engine. An air filter is positioned in the air filter box to filtering air entering the internal combustion engine.

A supercharger outlet resonator comprises a housing, a first surface comprising a first opening and a housing axis bisecting the first opening, and a second surface comprising a second opening, the second surface located parallel to the first surface. A channel is perpendicular to the housing axis and connects the first opening to the second opening. The channel comprises at least one sidewall. An envelope is fluidly separated from the channel by the at least one sidewall, the envelope at least partially surrounds the channel, and the envelope extends from the first surface to the second surface. The envelope comprises a third opening and at least one second sidewall. A noise-reducing material located on the housing.

An intake structure of an outboard motor supplying intake air to an internal combustion engine for the outboard motor has an engine cover covering the internal combustion engine for the outboard motor, an inner cover disposed on an outside of the engine cover, and a top cover covering the inner cover. The inner cover and the top cover form an intake duct supplying intake air to the internal combustion engine for the outboard motor.

A resonator (12) for reducing intake air noise is connected to an intake air duct (6) connecting a throttle chamber (5) and an air cleaner case (7). This blow-by gas treatment device is equipped with a fresh air introduction passage comprising a fresh air introduction hose (16), and a blow-by gas passage comprising a blow-by gas hose (20), with the fresh air introduction hose (16) connecting a cylinder head cover (4) and the resonator (12). A connector part (15) of the resonator (12) to which the fresh air introduction hose (16) is connected is provided with an orifice (21) formed integral with a lower body (13) formed of a synthetic resin, as a part thereof. Pulsation is effectively reduced by the throttling effect of the orifice (21) and the expansion effect of the resonator (12).

Disclosed herein is an engine intake device for a forklift. The engine intake device for a forklift includes an intake flow path passing through a counterweight of the forklift, and an intake pipe connected to the intake flow path to provide intake air to an engine of the forklift.

There is provided an intake apparatus of an engine for an outboard motor. An intake manifold, a throttle body and an intake silencer box are arranged at one of right and left sides of an engine block which is configured such that an axial direction of a cylinder coincides with a front and rear direction of the outboard motor. An intake duct communicating with an intake introduction port provided at an upper part of an engine cover is coupled to an upstream end of the intake silencer box. A first water separation part is arranged between the intake introduction port and the intake duct. A second water separation part is provided below a duct part of the intake duct. The second water separation part is formed by providing a drain hole at a bottom part of a resonator chamber part communicating with the duct part to reduce an intake noise.

An air filter housing includes an inner housing space adapted to receive an air filter element. The air filter housing includes a first end and a second end located axially opposite the first end in relation to the inner housing space, and an outlet channel path extending from the inner housing space and out from the second end, the outlet channel path having a length X m, the length X m being adapted to stabilize a noise having a wavelength of Y m travelling through the outlet channel path towards the inner housing space, wherein the length X m is related to the wavelength Y m according to the following relationship: Y/16<X<Y/8.