Exhaust gas bypass valve system for a turbocharged engine

1. A system comprising:

an exhaust gas bypass valve coupled within a bypass pipe

a tuned pipe coupled to an exhaust manifold of an engine, said tuned pipe comprising a diverging portion and a converging portion;

a housing having a passage therethrough;

an exhaust gas bypass valve coupled within a bypass pipe, said bypass valve comprising a valve member rotatably coupled within the housing and fluidically coupled to the tuned pipe, said valve member rotating about a valve axis, said valve member substantially balanced about the valve axis;

a turbocharger;

a motor coupled to the valve member;

a motor position sensor coupled to the motor generating a motor position signal;

an engine speed sensor generating an engine speed signal;

a throttle position sensor generating a throttle position signal;

a boost pressure sensor generating a boost pressure signal corresponding to a boost pressure of the turbocharger;

a tuned pipe pressure sensor generating a tuned pipe pressure signal;

a tuned pipe temperature sensor generating a tuned pipe temperature signal; and

a controller coupled to the motor position sensor, the throttle position sensor, the tuned pipe pressure sensor, the tuned pipe temperature sensor, and the boost pressure sensor, the controller controlling the motor to control a position of the valve member in response to the motor position signal, the engine speed signal, the throttle position signal, the boost pressure signal, the tuned pipe pressure signal and the tuned pipe temperature signal.

2. The system as recited in claim 1 further comprising a first valve seat disposed partially circumferentially within said passage and extending radially inwardly from the housing.

3. The system as recited in claim 2 further comprising a second valve seat disposed within and partially circumferentially around the passage.

4. The system as recited in claim 3 wherein the first valve seat comprises a first surface and the second valve seat comprises a second surface, said first surface opposed to the second surface.

5. The system as recited in claim 4 wherein the first surface is parallel to the second surface.

6. The system as recited in claim 5 wherein the first surface and the second surface are directly adjacent and touching the valve member when the valve member is in a closed position.

7. The system as recited in claim 5 wherein the first surface and the second surface are normal to a flow direction through the valve member.

8. The system as recited in claim 3 wherein the first valve seat and the second valve seat are integrally formed with the housing.

9. The system as recited in claim 3 wherein the housing has an outer wall having a first thickness and said outer wall having a second thickness greater than the first thickness at the first valve seat and the second valve seat.

10. The system as recited in claim 1 wherein the motor is coupled to the valve member with an arm.

11. The system as recited in claim 1 wherein the valve member is a butterfly valve.

12. The system of claim 1 wherein the passage comprises an effective passage area, said passage sized as a function of engine displacement.

13. The system of claim 1 wherein the passage comprises an effective passage area, said passage sized as a function of engine power output.

14. The system of claim 1 wherein the passage comprises an effective passage area, said passage sized as a function of displacement of the engine and power output of the engine.

15. The system of claim 1 further comprising an exhaust manifold pressure sensor generating an exhaust manifold pressure signal, said controller coupled to the exhaust manifold pressure sensor controlling the motor to control the position of the valve member in response to the exhaust manifold pressure signal.

16. The system of claim 1 further comprising an exhaust manifold temperature sensor generating an exhaust manifold temperature signal, said controller coupled to the exhaust manifold temperature sensor controlling the motor to control the position of the valve member in response to the exhaust manifold temperature signal.