A supercharging system for an internal combustion engine provided with a plurality of turbochargers includes: a state-amount detection part configured to detect a state amount related to an operational state of the internal combustion engine; and a control part configured to control at least one of an intake flow-passage switching valve or an exhaust flow-passage switching valve so that an operation mode transitions from a first operation mode to a second operation mode if the state amount is at least a threshold selected corresponding to the state amount on the basis of a first threshold function, and so that the operation mode transitions from the second operation mode to the first operation mode if the state amount is less than a threshold selected corresponding to the state amount on the basis of a second threshold function. The first threshold function and the second threshold function are set to be different from each other.

A supercharging system for an internal combustion engine provided with a plurality of turbochargers includes: a state-amount detection part configured to detect a state amount related to an operational state of the internal combustion engine; and a control part configured to control at least one of an intake flow-passage switching valve or an exhaust flow-passage switching valve so that an operation mode transitions from a first operation mode to a second operation mode if the state amount is at least a threshold selected corresponding to the state amount on the basis of a first threshold function, and so that the operation mode transitions from the second operation mode to the first operation mode if the state amount is less than a threshold selected corresponding to the state amount on the basis of a second threshold function. The first threshold function and the second threshold function are set to be different from each other.

A turbo-boost controlled intake system is disclosed that provides a driver of a vehicle with greater control over vehicle performance. The turbo-boost controlled intake system includes a control module that is coupled with an aircharger air intake. The control module instructs an electronic control unit of the vehicle to increase manifold pressure to a higher level before releasing the pressure through a waste gate so as to provide a greater power output of the engine. The turbo-boost controlled intake system further includes a wiring harness and a signal adjuster. The wiring harness couples the control module with a turbo inlet pressure sensor, a manifold absolute pressure sensor, and an electronic control unit of the vehicle. The signal adjuster includes a rheostat that enables manual adjustment of the power output of the engine.

A turbo-boost controlled intake system is disclosed that provides a driver of a vehicle with greater control over vehicle performance. The turbo-boost controlled intake system includes a control module that is coupled with an aircharger air intake. The control module instructs an electronic control unit of the vehicle to increase manifold pressure to a higher level before releasing the pressure through a waste gate so as to provide a greater power output of the engine. The turbo-boost controlled intake system further includes a wiring harness and a signal adjuster. The wiring harness couples the control module with a turbo inlet pressure sensor, a manifold absolute pressure sensor, and an electronic control unit of the vehicle. The signal adjuster includes a rheostat that enables manual adjustment of the power output of the engine.

A control device estimates a leakage gas amount with respect to gas that leaks to an upstream side from a downstream side of a fresh air introduction valve when the fresh air introduction valve is closed. If the leakage gas amount is equal to or greater than a predetermined value when there is a request to open the fresh air introduction valve, a target opening degree of the fresh air introduction valve is determined based on the engine speed and intake pressure, and also a correction opening degree with respect to the target opening degree is calculated based on the leakage gas amount. The fresh air introduction valve is opened to an opening degree greater than the target opening degree by an amount corresponding to the correction opening degree, to thereby cause leakage gas that is accumulated in a fresh air introduction passage to flow into an intake passage together with a required amount of fresh air.

A control device estimates a leakage gas amount with respect to gas that leaks to an upstream side from a downstream side of a fresh air introduction valve when the fresh air introduction valve is closed. If the leakage gas amount is equal to or greater than a predetermined value when there is a request to open the fresh air introduction valve, a target opening degree of the fresh air introduction valve is determined based on the engine speed and intake pressure, and also a correction opening degree with respect to the target opening degree is calculated based on the leakage gas amount. The fresh air introduction valve is opened to an opening degree greater than the target opening degree by an amount corresponding to the correction opening degree, to thereby cause leakage gas that is accumulated in a fresh air introduction passage to flow into an intake passage together with a required amount of fresh air.

A valve device for a vehicle may include a pneumatic valve having first and second chambers in which respective pressures thereof are regulated, and a pressure regulation valve coupled to the pneumatic valve, the pressure regulation valve communicating with the first chamber, including a positive pressure side opening and a negative pressure side opening, and selectively opening and closing the positive pressure side opening and the negative pressure side opening to regulate the pressure in the first chamber.

An air induction system for a vehicle includes a turbocharger having a compressor side inlet and a bifurcated clean air intake system having a bifurcated conduit. The bifurcated conduit includes an upstream end configured to receive intake air, a downstream end configured to supply intake air to the compressor side inlet, an inner passage configured to supply intake air to the downstream end, and an outer passage disposed about the inner passage and separated from the inner passage by an inner wall, the outer passage configured to selectively receive recirculation backflow from the compressor side inlet. A port is fluidly coupled between the outer passage and another location of the vehicle. The port is configured to selectively evacuate at least a portion of the recirculation backflow to the another location the vehicle.

Methods and systems for improving operation of an engine at higher speeds and loads are disclosed. In one example, fuel may be injected to an exhaust system of the engine so that temperatures of exhaust system components may be reduced when the engine is operated at higher speeds and loads.

Methods and systems for operating an engine during conditions where ambient humidity changes over time are presented. In one non-limiting example, an engine air flow limit is adjusted to increase engine air flow during high humidity conditions such that an engine may provide equivalent torque output during the high humidity conditions as compared to when the engine is operated during low humidity conditions.