An exhaust muffler includes a first muffler section having a tubular member made up of an inner pipe to which an exhaust pipe is connected and an outer pipe covering the inner pipe, and a connector connecting the tubular member and a second muffler section to each other, and the second muffler section having an outer shell, a first partition wall, a second partition wall, and a third partition wall. Exhaust gases delivered from the exhaust pipe are discharged from the first muffler section and the second muffler section out of the exhaust muffler. The second muffler section has a cross-sectional area larger than a cross-sectional area of the tubular member. The exhaust muffler includes a first expansion chamber, a second expansion chamber, and a third expansion chamber. The second muffler section includes a fluid communication pipe extending through the first partition wall and the second partition wall for leading exhaust gases from the first expansion chamber into the second expansion chamber, and an exhaust passage pipe held in fluid communication with the third expansion chamber and extending through the second partition and the third partition wall. The second partition wall has a fluid communication hole defined therein that provides fluid communication between the second expansion chamber and the third expansion chamber. There is thus provided an engine exhaust device capable of increasing a silencing capability by increasing the length of a route through which the exhaust gases flow while maintaining the length of the exhaust device.

An engine system and method of operating the same includes a two stroke engine, an exhaust manifold coupled to the two-stroke engine, a tuned pipe coupled to the exhaust manifold coupled to the exhaust manifold, a stinger pipe coupled to the tuned pipe, a silencer coupled to the tuned pipe and an exhaust pipe, and an exhaust bypass valve. Exhaust gases are directed from the two stroke engine through an exhaust manifold and through a tuned pipe. An opening of the exhaust bypass valve is changed to redirect exhaust gases away from the tuned pipe to change a pressure within the tuned pipe. In response to changing the opening of the exhaust bypass valve, the airflow through the engine is changed.

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.

There is provided a straddle-type vehicle. An exhaust pipe includes a first portion extending downward from an exhaust port through a region in front of an engine and on one lateral side of a down frame in the left-right direction, a second portion extending upward through a region in front of the engine and on the other lateral side of the down frame in the left-right direction after extending from a downstream side end portion of the first portion to the other lateral side of the down frame in the left-right direction through a region in front of or to the lower front of the down frame. The catalyst device is disposed in a portion of the second portion of the exhaust pipe that is located in front of the engine and on the other lateral side of the down frame in the left-right direction.

An engine system comprises a two stroke engine, an exhaust manifold, a tuned pipe coupled to the exhaust manifold and a turbocharger coupled to the engine. The turbocharger comprises a turbine inlet coupled to the exhaust manifold through the tuned pipe, and a turbine outlet coupled to an exhaust pipe. A silencer is coupled to the exhaust pipe. A bypass pipe has a first end coupled to the tuned pipe and a second end bypassing the turbine outlet and a wastegate disposed in the bypass pipe.

A novel catalyst constituent material for combustion gas purification, which has an extremely good ratio of contact between each catalyst metal particle and an exhaust gas; and catalyst device which uses this catalyst constituent material for combustion gas purification; and a method for producing this catalyst constituent material for combustion gas purificaton. The catalyst constituent obtained by mixing catalyst metal particles and a pore-forming material that disappears at high temperatures into a catalyst supporting material which is a slurry containing fine ceramic particles. The pore-forming material also contains long fibers of cellulose nanofibers and/or short fibers of cellulose nanofibers.

A stainless steel foil having a chemical composition comprising, by mass %, C: 0.015% or less, Si: 0.50% or less, Mn: 0.50% or less, P: 0.040% or less, S: 0.010% or less, Cr: 10.0% or more and less than 16.0%, Al: 2.5 to 4.5%, N: 0.015% or less, Ni: 0.05 to 0.50%, Cu: 0.01 to 0.10%, Mo: 0.01 to 0.15%, at least one selected from the group consisting of Ti: 0.01 to 0.30%, Zr: 0.01 to 0.20%, Hf: 0.01 to 0.20%, and REM: 0.01 to 0.20%, where Ti+Zr+Hf+2REM≥0.06 and 0.30≥Ti+Zr+Hf are satisfied.

An arrangement structure of an exhaust gas sensor includes an exhaust pipe that extends from an engine for a vehicle to form a part of an exhaust flow path, a catalytic device that purifies exhaust gas flowing through the exhaust flow path, and a first exhaust gas sensor that detects a predetermined component in the exhaust gas. The exhaust pipe is led out from a front side of the engine to one side in a left-right direction of the engine, and extends rearward so as to be routed on a lateral side of the engine. The catalytic device is arranged in the middle of the exhaust pipe on the lateral side of the engine. The first exhaust gas sensor is arranged on the lateral side of the engine and on an upstream side or a downstream side of the catalytic device in the exhaust pipe.

An exhaust assembly for a vehicle. The exhaust assembly includes a header assembly including one or more head pipes, and a bridge with a first end and a second end that is opposite the first end. The first and second ends are secured to the header assembly. The exhaust assembly further includes a shield assembly including a shield shaped to cover a portion of the header assembly and a retainer secured to the shield and supported by the bridge by a planar clamp joint therebetween.

An exhaust system is disclosed. A method of providing the exhaust system is also included. A vehicle may implement the exhaust system. In certain examples, the exhaust system includes a muffler having an exhaust inlet and an exhaust outlet. The exhaust system also includes a housing disposed around the muffler. The housing includes, in certain examples, a first exhaust opening disposed adjacent the exhaust outlet and configured to receive exhaust gasses from the exhaust outlet and direct the exhaust gasses away from the exhaust system in a normal operating mode, and a second exhaust opening configured to draw in ambient air in the normal operating mode.