Methods and systems are provided for adjusting a position of an exhaust valve that regulates engine exhaust noise. In one example, the position of the exhaust valve is adjusted according to a road grade estimate. The road grade estimate may be based on a vehicle's present position on a road or a position that is a distance away from the vehicle's present position.

A system for regulating performance characteristics of a vehicle includes an engine configured to output an exhaust gas. The system further comprises an emissions system in fluid communication with the engine, the emissions system configured to clean the exhaust gas. The system further comprises a valve system in fluid communication with the emissions system, the valve system configured to regulate a flow of the exhaust gas. The valve system comprises a vane movable between a forward open position, a closed position, and a rear open position. The valve system further comprises a biasing member configured to bias the vane in the forward open position. The valve system further comprises a bypass channel configured to provide a bypass flow path for the exhaust gas to control a backpressure on the vane.

Vehicle sound attenuation systems and methods are provided herein. An example method includes determining a triggering event for a vehicle using an advanced driver assisted technology system, and controlling a sound enhancing system of the vehicle in response to the triggering event. Controlling the sound enhancing system may include attenuating engine or exhaust sound produced by the sound enhancing system of the vehicle.

Methods and systems are provided for diagnosing an active exhaust valve in an exhaust system based on thermal data. In one example, a method may include indicating degradation of a first active exhaust valve positioned in a first exhaust pipe of a first engine bank based on a difference between a first temperature of exhaust downstream of the first active exhaust valve and a second temperature of exhaust downstream of a second active exhaust valve positioned in a second exhaust pipe of a second engine bank. Degradation of the valve may be confirmed based on thermal image data acquired at outlets of the first and second exhaust pipes.

The muffler for a motorized vehicle includes a housing with an inlet chamber and an outlet chamber, an exhaust inlet, and an exhaust outlet. The muffler includes a first channel with a first noise dampening amount that is within the housing interior, to fluidly connect the inlet chamber and the outlet chamber. The muffler includes second channel with a second noise dampening amount that is within the housing interior between the inlet chamber and the outlet chamber. The first noise dampening amount is greater than the second noise dampening amount. A valve selectively fluidly connects the inlet chamber and the outlet chamber thorough the second channel, and is configured to variably obstruct the flow of exhaust gas through the second channel. In various embodiments, the muffler has more than one inlet chamber and more than one exhaust outlet.

A valve includes a valve body having an exhaust gas inlet and an exhaust gas outlet, the valve body defining an exhaust gas circulation passage between the exhaust gas inlet and the exhaust gas outlet. A flap is arranged in the valve body and a shaft drives the flap in rotation with respect to the valve body. At least one guide bearing guides the drive shaft of the flap for rotation relative to the valve body. The guide bearing is engaged through an orifice of the valve body, with an inner end of the guide bearing being located inside the valve body. A first tube is engaged in one of the exhaust gas inlet and exhaust gas outlet and abuts against the inner end of the guide bearing.

Methods and systems are provided for an exhaust muffler system with multiple inlets of different diameters. In one example, the muffler system may include multiple sets of inlet pipes to a muffler with each set of inlet pipes including pipes of different diameters with valves controlling exhaust flow into the inlet pipes. Exhaust from an engine bank may flow to a distinct set of inlet pipes and a distinct outlet pipe of the muffler via a separate exhaust passage.

A muffler for a vehicle includes: a muffler shell; a baffle disposed within the muffler shell, and having a first opening and a second opening which allow an exhaust gas to pass therethrough; and a variable valve mounted on the baffle. In particular, the variable valve includes: a valve plate rotatably mounted to open and close the first opening of the baffle; a valve arm connected to the valve plate; and a valve actuator to move the valve arm by variations in pressure of the exhaust gas. The valve plate is capable of rotating in a plane parallel to a plane of the baffle.

A fluid flow network for a vehicle includes first and second flow ducts having a common inlet and a common outlet; a flow directing member movable about a first axis and configured to direct flow from the common inlet to at least one of the first and second flow ducts; a flow reactive member configured to detect an imbalance between the flow exiting the first flow duct and the flow exiting the second flow duct; and means for adjusting the position of the flow directing member if an imbalance is detected by the flow reactive member.

Methods and systems are provided for an exhaust tuning valve. In one example, a method may include adjusting the exhaust tuning valve in response to a steering wheel angle input. Additionally or alternatively, the position of the exhaust tuning valve may be adjusted differently in response to a same steering wheel angle input during different driving behaviors.