A boost purge ejector tee arrangement is integrated into a turbocompressor associated with an engine and includes first and second passages, an inlet port and a nozzle. The first passage is formed into a housing of the turbocompressor and includes an outlet in communication with a turbocompressor inlet. The second passage is formed into the housing and includes a boost air inlet in communication with an internal outlet area of the turbocompressor and intersecting the first passage. The inlet port is associated with the housing and intersects the first passage. The nozzle is positioned in the first passage such that an outlet of the nozzle is proximate the intersection of the inlet port and first passage. During a boost mode of operation, the second passage is adapted to receive boost air flow, which flows through the nozzle thereby creating a vacuum and drawing purge through the inlet port.

An air intake duct, of a saddle-riding type vehicle, in which a flow velocity of an intake air is less likely to be reduced to enable prevention of reduction of an efficiency of a supercharger, is provided. The air intake duct of a motorcycle serves to supply incoming wind as the intake air to the supercharger for a combustion engine. The air intake duct has a passage area that is gradually reduced from an air intake port at a front portion toward a downstream portion connected to the supercharger at a rear portion.

An air intake duct, of a saddle-riding type vehicle, in which a flow velocity of an intake air is less likely to be reduced to enable prevention of reduction of an efficiency of a supercharger, is provided. The air intake duct of a motorcycle serves to supply incoming wind as the intake air to the supercharger for a combustion engine. The air intake duct has a passage area that is gradually reduced from an air intake port at a front portion toward a downstream portion connected to the supercharger at a rear portion.

A turbocharger is provided that includes a turbine housing including a gas inlet passage. A turbine wheel has a plurality of blades and is arranged in the turbine housing. A bearing housing is connected to the turbine housing. A shaft is rotatably supported in the bearing housing and connected to the turbine wheel. A shroud is arranged in surrounding relation to at least a portion of the turbine wheel, the shroud being arranged in spaced relation from and not in contact with the turbine housing. A fastening system secures the shroud relative to the bearing housing. The fastening system is configured to fracture when a force is exerted on the shroud corresponding to at least a portion of the turbine wheel contacting the shroud.

A turbocharger is provided that includes a turbine housing including a gas inlet passage. A turbine wheel has a plurality of blades and is arranged in the turbine housing. A bearing housing is connected to the turbine housing. A shaft is rotatably supported in the bearing housing and connected to the turbine wheel. A shroud is arranged in surrounding relation to at least a portion of the turbine wheel, the shroud being arranged in spaced relation from and not in contact with the turbine housing. A fastening system secures the shroud relative to the bearing housing. The fastening system is configured to fracture when a force is exerted on the shroud corresponding to at least a portion of the turbine wheel contacting the shroud.

An engine system and method utilizing a compressor map to control compressor speed of a driven turbocharger in the engine system is provided. A desired compressor speed is determined that corresponds to a boost pressure and to a mass flow rate of intake from the compressor map. The transmission of the driven turbocharger is shifted to a ratio that drives the compressor to a desired speed to provide the desired boost pressure and air flow to the engine system.

An engine system and method utilizing a compressor map to control compressor speed of a driven turbocharger in the engine system is provided. A desired compressor speed is determined that corresponds to a boost pressure and to a mass flow rate of intake from the compressor map. The transmission of the driven turbocharger is shifted to a ratio that drives the compressor to a desired speed to provide the desired boost pressure and air flow to the engine system.

It is intended to provide: an electric supercharging apparatus wherein, with a simple structure, rotor windage loss in an electric motor for driving a compressor is reduced and good cooling performance is produced; and a multi-stage supercharging system using the electric supercharging device. This electric supercharging apparatus is provided with: a first cooling passage formed in a stator along a motor coil and communicating a gas supply port with a gas discharge port in a motor housing; and a first intake passage connecting the gas discharge port to an intake port of a compressor. This electric supercharging apparatus is configured to introduce outside air into the first cooling passage via the gas supply port by applying negative pressure to the first cooling passage via the first intake passage, thereby cooling the inside of the motor housing.

An air intake chamber for a motorcycle is disposed downstream of a supercharger, for pressurizing and supplying an intake air to an engine, and upstream of a throttle body, for controlling the amount of the intake air to be supplied to an air intake port of the engine. The air intake chamber serves to accumulate the high pressure intake air discharged from the supercharger. The air intake chamber is provided with an injector, which has a fuel injecting port positioned at a location displaced from an axis of an outlet of the air intake chamber.

An air intake chamber for a motorcycle is disposed downstream of a supercharger, for pressurizing and supplying an intake air to an engine, and upstream of a throttle body, for controlling the amount of the intake air to be supplied to an air intake port of the engine. The air intake chamber serves to accumulate the high pressure intake air discharged from the supercharger. The air intake chamber is provided with an injector, which has a fuel injecting port positioned at a location displaced from an axis of an outlet of the air intake chamber.