A straddled vehicle having an engine unit supported by a vehicle body frame. The engine unit includes an engine body, a turbocharger, and an exhaust device. The exhaust device includes an exhaust pipe and a muffler that are connected to each other to form a portion of an exhaust passage, to allow the exhaust gas passed through the turbocharger to pass therethrough, and a first catalyst and a second catalyst that are arranged in this order along a direction in which the exhaust gas flows through the exhaust pipe. The exhaust pipe has an upstream end thereof connected to the turbocharger, a downstream end thereof connected to the muffler, and a corner section that is bent in at least a part thereof between a downstream end of the first catalyst and an upstream end of the second catalyst, the catalysts not being arranged in the corner section.

A timbre-scaled exhaust assembly includes: an acoustic portion including an inlet collector including an entrance duct at a first end of the collector in fluid for receiving an exhaust flow from an internal combustion engine and exit ducts at a second end of the collector in fluid communication with a plurality of non-perforated tuning tubes; an outlet collector including entrance ducts in fluid communication with the plurality of non-perforated tuning tubes and an exit duct in fluid communication with an outlet of the exhaust assembly. The inlet collector splits the exhaust flow from the internal combustion engine into the plurality of tuning tubes such that a plurality of distinct exhaust flows pass through the plurality of tuning tubes and the outlet collector combines the exhaust flow. A combined exhaust flow exits the exhaust system through the exhaust tip.

The invention presented is a crossover section for a vehicle exhaust system that includes a middle pipe and two outer pipes, each outer pipe in contact with and attached to the middle pipe. Diversion gates extend from the middle pipe into each of the outer pipes to divert a sample of exhaust gas into the middle pipe. A sensor, such as an oxygen sensor, is provided to measure one or more components of the combined exhaust. Also provided is an exhaust system that includes the inventive crossover section and a vehicle that includes one or more of the inventive exhaust systems.

A mixer for an exhaust system of an internal combustion engine for mixing exhaust gas and reactant includes a mixing chamber, a reactant dispensing arrangement for dispensing reactant into the mixing chamber axially between an upstream mixer wall and a downstream mixer wall, an inlet opening arrangement in the upstream mixer wall, an outlet opening arrangement in the downstream mixer wall, a flow guiding arrangement arranged between the upstream mixer wall and the downstream mixer wall, wherein the flow guiding arrangement provides a first flow path leading from the inlet opening arrangement to the outlet opening arrangement and a second flow path leading from the inlet opening arrangement to the outlet opening arrangement, wherein each flow path has at least two flow channels leading from the inlet opening arrangement to the outlet opening arrangement.

A catalytic converter is provided with: an inlet-side diffuser part; an outlet-side diffuser part; a case including an upstream-side cylindrical part and a downstream-side cylindrical part; an inner liner provided in the upstream-side cylindrical part; a first catalyst retained inside the inner liner; and a second catalyst retained inside the downstream-side cylindrical part. An end face of the second catalyst faces a peripheral surface of the inner liner. An annular flow path is provided between the upstream-side cylindrical part and the inner liner, and the first catalyst is insulated from heat by the annular flow path. A part of exhaust flows into the second catalyst via the annular flow path.

In an exhaust gas purification filter, a partition wall has communicating pores. Each communicating pore has a surface opening on the gas-inflow-side surface and a plurality of portions, each portion having a diameter being reduced and then increased from the surface opening, one of the portions, whose diameter is the smallest, being defined as an inlet neck portion. As viewed in cross section in a thickness direction of the partition wall, the surface opening of each communication pore has a diameter defined as a surface opening diameter, the inlet neck portion of each communication pore has a diameter defined as an inlet neck diameter. The inlet neck diameter is smaller than the surface opening diameter, and an average value of the inlet neck diameters is 15 μm or less. A surface opening ratio of the communicating pores in plan view of the gas-inflow-side partition wall surface is 40% or more.

A saddle-riding type vehicle exhaust structure includes: an exhaust pipe that is connected to an exhaust port connecting to a combustion chamber of an engine and has a circular cross-sectional shape which is orthogonal to an exhaust flow direction; and a muffler that is connected to a downstream side in the exhaust flow direction of the exhaust pipe, wherein the exhaust pipe includes a muffler connection part that is connected to the muffler, an exhaust pipe upstream part that is connected to an upstream side in the exhaust flow direction of the muffler connection part, and an exhaust pipe downstream part that is connected to a downstream side in the exhaust flow direction of the muffler connection part, a cross-sectional area that is orthogonal to the exhaust flow direction of the muffler connection part is larger than each of a minimum value of a cross-sectional area that is orthogonal to an exhaust flow direction of the exhaust pipe upstream part and a minimum value of a cross-sectional area that is orthogonal to an exhaust flow direction of the exhaust pipe downstream part, and a vehicle width direction size of the cross-sectional shape of the muffler connection part and a vertical direction size of the cross-sectional shape of the muffler connection part are different from each other.

Disclosed is a water ingress preventive structure for a tailpipe which discharges exhaust gas outside of a vehicle at a terminal of an exhaust passage system. A curved shape is imparted to the tailpipe. A partition is mounted on an inner periphery of a curved portion outward of a curved direction so as to be gradually spaced apart from the inner periphery toward downstream in a direction of flow of the exhaust gas. Thus, a dead end portion is defined by the partition and the inner periphery of the curved portion outward of the curved direction.

An exhaust system for an engine has a volume element such as a muffler or a silencer. First and second exhaust pipes are connected as dual exhaust pipes upstream of or downstream of the volume element. The first exhaust pipe has a first length (L1). A valve is positioned in the second exhaust pipe at a distance (D) from the volume element. The distance D is a fraction of L1 such that the second pipe is a resonator for the first pipe with the valve in a closed position. A method of controlling exhaust noise includes positioning a valve in the first exhaust pipe at a distance (D) from a volume element with D being a specified fraction of a length of the second exhaust pipe, and closing the valve such that the first pipe provides a resonator for the second pipe to counteract standing wave in the second pipe.

Described herein is a process for increasing mass flow of an exhaust gas through a catalytic converter system for a vehicle. The process may comprise determining a centerline and corresponding cumulative centerline bend angle of a first catalytic converter system spanning from an inlet point at a first end of the catalytic converter systems exhaust pipe to an outlet point at a second end of the catalytic converter systems extension pipe. Once determined, the cumulative centerline bend angle may be increased by increasing an individual bend radius of at least one bend within the exhaust pipe and/or within the extension pipe.