A valve system comprising a valve chamber at a junction of an inlet port, an outlet port and a bypass port, the inlet port configured for fluid communication with exhaust gas, the outlet port configured for fluid communication with an inlet of a turbine, and the bypass port configured for fluid communication with an exhaust aftertreatment device; a rotary valve comprising a valve rotor which rotates about a valve axis within the valve chamber between a first position to permit gas flow through the bypass port and a second position to block gas flow. At least one of the valve rotor and the valve chamber comprises a protrusion and the other comprises a recess, wherein, in the first position, the protrusion and recess are spaced from one another, and, in the second position the recess receives the protrusion such that gas flow between the protrusion and recess is substantially prevented.

An exhaust pulse balance chamber comprising a circular collar, mid-section that bulges at its center, skirt, and right and left legs, all of which are sealed to the exterior environment and in fluid communication with one another. The outer diameter of the skirt increases in width but not in depth from the proximal end of the skirt to the distal end of the skirt, which is configured to receive the right and left legs. Each leg is bent at a 30-degree angle relative to the central longitudinal axis of the exhaust pulse balance chamber. The invention includes a method of using the exhaust pulse balance chamber to convert a vehicle from a dual-in, single-out exhaust system to a dual-in, dual-out exhaust system.

A muffler for use with an internal combustion engine is provided. The muffler includes a first tube configured to receive a first exhaust stream. The first tube includes a first inlet portion, a first outlet portion spaced apart from the first inlet portion, and a first intermediate portion extending between the first inlet portion and the first outlet portion. The muffler also includes a second tube configured to receive a second exhaust stream. The second tube includes a second inlet portion, a second outlet portion spaced apart from the second inlet portion, and a second intermediate portion extending between the second inlet portion and the second outlet portion. The first intermediate portion and the second intermediate portion cross each other, are at least partially stacked on each other, and are in fluid communication with each other.

An exhaust gas aftertreatment system includes a housing assembly and a reductant delivery system. The housing assembly includes an upstream housing, a first inlet tube, a second inlet tube, and a mixing housing. The first inlet tube is coupled to the upstream housing and configured to receive a first portion of exhaust gas from the upstream housing. The second inlet tube is coupled to the upstream housing and configured to receive a second portion of the exhaust gas from the upstream housing. The mixing housing is coupled to the first inlet tube and the second inlet tube. The mixing housing is configured to receive the first portion of the exhaust gas from the first inlet tube and receive the second portion of the exhaust gas from the second inlet tube. The mixing housing is separated from the upstream housing by the first inlet tube and the second inlet tube.

An exhaust structure for a saddle riding vehicle includes: an exhaust pipe connected to an internal combustion engine; and a catalyst disposed in the exhaust pipe; the exhaust pipe including a catalyst case unit housing the catalyst and upstream side exhaust pipes disposed on an upstream side of the catalyst case unit; the catalyst case unit having a larger diameter than the upstream side exhaust pipes; the upstream side exhaust pipes being connected to the catalyst case unit in a connecting portion located on an upstream side of the catalyst in a flow of exhaust; in the connecting portion, axes of the upstream side exhaust pipes and an axis of the catalyst case unit being in substantially right-angled positional relation to each other.

A multi-mode muffler for an exhaust system of an internal combustion engine provides a rotary plate that modulates exhaust gas flow between a first and second flow path. Each flow path may provide different sound dampening characteristics, thereby providing different sound profiles with the same muffler. In a disclosed embodiment, the rotary plate is driven by a shaft coupled to an external actuator. Also, a third possible position of the rotary plate may allow flow through both the first and second flow paths, thereby providing a third possible noise profile. One of the sound profiles may be louder than the other thereby allowing the muffler to switch between “loud” and “quiet” modes of operation.

The dual inlet exhaust design for the flying device incorporates easy-to-assemble designs with low number of components, suitable for limited space and small volume requirements, good performance. The exhaust is designed as a three-chamber cylinder with two coaxial inlet pipes running through the two chambers on both sides, extending into the middle compartment. The width of the two inlet tubes in the middle compartment is different. The inlet pipe at the two compartments on both sides has a bore. The outlet tube is located in the middle compartment, deviating to the side with a smaller expansion inlet, with the longitudinal axis of the outlet tube passing through the inlet tube.

Exhaust systems for a vehicle are provided. In one example, an exhaust system includes a muffler, a first exhaust outlet pipe fluidly coupled to a first outlet of the muffler, a second exhaust outlet pipe fluidly coupled to a second outlet of the muffler, a bypass duct fluidly coupled to a third outlet of the muffler, and a combined X-Y shaped intersection at which the first exhaust outlet pipe, the second exhaust outlet pipe, and the bypass duct are fluidly coupled to each other.

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.

An exhaust gas aftertreatment system includes a housing assembly and a reductant delivery system. The housing assembly includes an upstream housing, a first inlet tube, a second inlet tube, and a mixing housing. The first inlet tube is coupled to the upstream housing and configured to receive a first portion of exhaust gas from the upstream housing. The second inlet tube is coupled to the upstream housing and configured to receive a second portion of the exhaust gas from the upstream housing. The mixing housing is coupled to the first inlet tube and the second inlet tube. The mixing housing is configured to receive the first portion of the exhaust gas from the first inlet tube and receive the second portion of the exhaust gas from the second inlet tube. The mixing housing is separated from the upstream housing by the first inlet tube and the second inlet tube.