A method of operating a forced induction gaseous-fueled engine includes mixing gaseous-fuel and engine intake air to form a mixture at a fuel mixer. The method includes delivering the mixture to an intake manifold by at least partially bypassing a charge air cooler.

Systems, methods and apparatus are disclosed for providing reduced engine start times for a fumigation type internal combustion engine. A bypass is provided that directly connects the air-fuel mixer upstream of the compressor to the intake manifold, providing the air-fuel mixture to the intake manifold during engine startup.

A method of operating a forced induction gaseous-fueled engine includes mixing gaseous-fuel and engine intake air to form a mixture at a fuel mixer. The method includes delivering the mixture to an intake manifold by at least partially bypassing a charge air cooler.

An inlet duct, an induction system, and a system are disclosed for directing an inlet flow into an inlet compressor for use in an internal combustion engine. An example inlet duct may include one or more relief features disposed on an inner surface of the inlet duct. The one or more relief features may be made integral with the inlet duct. The one or more relief features may be disposed to protrude into the inlet flow to cause the inlet flow to swirl before reaching the inlet compressor.

A snowmobile includes an engine including an engine head including a cylinder head, a supercharger, an intake manifold, throttle bodies, first joints that connect the intake manifold to the throttle bodies, second joints that connect the throttle bodies to the cylinder head, and a restrictor that connects the engine head to the first joints. The restrictor includes an engaging member that fits into grooves of the first joints, and connectors that connect the engaging member and the engine head to each other. A steering shaft is inserted between two mutually adjacent first joints which have a distance from each other greater than a distance between the other two mutually adjacent first joints.

A supercharging system includes a supercharger including a motor generator, and an intake-side variable cam phase mechanism variably setting a valve-closing timing (IVC angle) of an intake valve. If an operation state of the engine is within a regenerative operation region, a turbine rotation speed controller controls a turbine rotation speed to a target turbine rotation speed set to optimize turbine efficiency by controlling an opening degree of a wastegate valve toward a closing side and by adjusting an amount of power generated by the motor generator. If the operation state is within the regenerative operation region and within a supercharging operation region, a torque controller controls a generated torque to a requested torque by performing cooperative control of an opening degree of an intake bypass valve, the IVC angle and an opening degree of an intake throttle valve.

An air intake device includes a bypass passage which makes a portion of an air intake passage on an upstream side of a compressor and a portion of the air intake passage on a downstream side of the compressor communicate with each other, and a bypass passage open/close valve which opens or closes the bypass passage. The air intake passage includes a first passage extending toward an upstream side from the compressor along a first direction, a bent portion bent from an upstream end of the first passage in a second direction, and a second passage extending from an upstream end of the bent portion along the second direction. The second passage has a vertically elongated cross-sectional shape. A vibration suppressing part for suppressing vibrations of the second passage is disposed in at least one of the second passage and the bent portion.

An intake system for a vehicle may include an intake manifold having an internal space divided into a first chamber and a second chamber by a partition wall, in which intake air flows into the first chamber through a charging path and is then discharged to a portion of an intake port connected to the intake manifold; and intake air flows into the second chamber through a bypass path bypassing charger and is then discharged to another portion of the intake port.

A straddle-type vehicle comprises a supercharging device which compresses intake-air, an air-intake chamber which is disposed downstream of the supercharging device, a pressure rising suppressing valve which is actuated by a pressure and connected to an inner space of the air-intake chamber, the pressure rising suppressing valve being configured to open the inner space of the air-intake chamber to a relief passage, in a case where a difference between a preset pressure in a pilot space and a pressure in the air-intake chamber reaches a predetermined value or more, a control valve which is electrically actuated and is capable of performing switching of a space to be in communication with the pilot space, between a high-pressure space and a low-pressure space; and a valve controller which provides to the control valve an operation command for controlling the control valve.

An electronic control unit diagnoses leakage abnormality in an intake system downstream from a supercharger provided in the intake system of the engine. The electronic control unit sets, as a supercharging region monitoring value, a ratio between a first air amount obtained from a detection value of an air flowmeter and a second air amount obtained from a detection value of an intake pressure sensor, the ratio being the ratio obtained when the engine is operated in a supercharging region. The electronic control unit also sets, as a non-supercharging region monitoring value, a ratio obtained when the engine is driven in a non-supercharging region. The electronic control unit determines the presence of the leakage abnormality in the intake system when the ratio of the supercharging region monitoring value to the non-supercharging region monitoring value is larger than a predetermined specified value.