Methods and systems are provided for an air intake system. In one example, an air intake system is provided. The air intake system includes a first air inlet duct providing intake air to an engine intake conduit, the first air inlet duct including an opening positioned external to an engine compartment. The air intake system also includes a second air inlet duct positioned upstream of the engine intake conduit and external to the engine compartment, the second air inlet duct including a funnel shaped to flow air to only a portion of an air filter.

Methods and systems are provided for an air intake system. In one example, an air intake system is provided. The air intake system includes a first air inlet duct providing intake air to an engine intake conduit, the first air inlet duct including an opening positioned external to an engine compartment. The air intake system also includes a second air inlet duct positioned upstream of the engine intake conduit and external to the engine compartment, the second air inlet duct including a funnel shaped to flow air to only a portion of an air filter.

An inlet duct includes a tubular main body formed by a compression-molded fibrous molded body. The main body includes an alternate layout region in which an air-impermeable high-compression portion and an air-permeable low-compression portion hat is compression-molded at a lower compressibility than a compressibility of the high-compression portion are alternately laid out in an axial direction of the main body. The alternate layout region is configured such that an arbitrary pair of points at an equal distance in the axial direction to a central position in an upstream region and a downstream region of the alternate layout region include only points that are both located in the low-compression portions and points one of which is located in the low-compression portion and the other one of which is located in the high-compression portion.

An inlet duct includes a tubular main body formed by a compression-molded fibrous molded body. The main body includes an alternate layout region in which an air-impermeable high-compression portion and an air-permeable low-compression portion hat is compression-molded at a lower compressibility than a compressibility of the high-compression portion are alternately laid out in an axial direction of the main body. The alternate layout region is configured such that an arbitrary pair of points at an equal distance in the axial direction to a central position in an upstream region and a downstream region of the alternate layout region include only points that are both located in the low-compression portions and points one of which is located in the low-compression portion and the other one of which is located in the high-compression portion.

An engine system may include: an engine including cylinders that generate a driving torque by combusting fuel; a first intake manifold connected to an intake line through which flows intake air into some of the plurality of cylinders; a second intake manifold supplying the intake air to the other cylinders of the plurality of cylinders through the first intake manifold; a first exhaust manifold connected to some cylinders that are connected to the first intake manifold; a second exhaust manifold connected to some other cylinders that are connected to the second intake manifold; a recirculation line branched from the second exhaust manifold to be coupled to the second intake manifold; a recirculation inlet valve disposed at a point at which the recirculation line and the second exhaust manifold are joined; and a manifold connection valve disposed on an intake line between the first intake manifold and the second intake manifold.

An engine system may include: an engine including cylinders that generate a driving torque by combusting fuel; a first intake manifold connected to an intake line through which flows intake air into some of the plurality of cylinders; a second intake manifold supplying the intake air to the other cylinders of the plurality of cylinders through the first intake manifold; a first exhaust manifold connected to some cylinders that are connected to the first intake manifold; a second exhaust manifold connected to some other cylinders that are connected to the second intake manifold; a recirculation line branched from the second exhaust manifold to be coupled to the second intake manifold; a recirculation inlet valve disposed at a point at which the recirculation line and the second exhaust manifold are joined; and a manifold connection valve disposed on an intake line between the first intake manifold and the second intake manifold.

A vehicle engine exhaust system with integrated exhaust gas recirculation (EGR) includes an exhaust manifold having multiple exhaust ports including a first exhaust port and a second exhaust port. The first exhaust port and the second exhaust port receive exhaust flow from a common exhaust split upstream of the first exhaust port and the second exhaust port. A valve assembly has a first butterfly valve positioned in the first exhaust port and a second butterfly valve positioned in the second exhaust port. A shaft is positioned within the exhaust manifold commonly connecting the first butterfly valve to the second butterfly valve to simultaneously rotate the first butterfly valve and the second butterfly valve.

A vehicle engine exhaust system with integrated exhaust gas recirculation (EGR) includes an exhaust manifold having multiple exhaust ports including a first exhaust port and a second exhaust port. The first exhaust port and the second exhaust port receive exhaust flow from a common exhaust split upstream of the first exhaust port and the second exhaust port. A valve assembly has a first butterfly valve positioned in the first exhaust port and a second butterfly valve positioned in the second exhaust port. A shaft is positioned within the exhaust manifold commonly connecting the first butterfly valve to the second butterfly valve to simultaneously rotate the first butterfly valve and the second butterfly valve.

An apparatus that controls a swirl ratio in a diesel engine for a motor vehicle includes a first intake port that directs a first airflow into a combustion chamber, and a second intake port that directs a second airflow into the combustion chamber. The first and second intake ports are arranged to direct the first airflow and the second airflow such that a desired swirl ratio is achieved in the combustion chamber.

An air filter device for a motor vehicle is provided with a filter housing having an air inlet and an air outlet, a filter insert which is received in the filter housing and divides the inside of the filter housing into an untreated air section and a pure air section, and a bypass line for supplying air into the untreated air section. The bypass line extends from a connection opening in the filter housing to a cooler, especially a charge air cooler of the motor vehicle.