A muffler for receiving exhaust gas from a combustion engine comprises a shell, first and second inlet pipes each having outlets providing exhaust gas to a mixing chamber within the shell, a first chamber and a second chamber positioned within the shell and a pair of communication pipes each including an inlet receiving exhaust gas from the mixing chamber. Each communication pipe includes an outlet providing exhaust to the second chamber. Each of the communication pipes further includes a Helmholtz opening positioned downstream of the mixing chamber. The Helmholtz openings are open to the first chamber.

A muffler includes a housing defining a first chamber, a second chamber and a third chamber. The muffler includes at least a pair of nested protrusions in communication with an inlet. The pair of nested protrusions is coupled to a respective surface of a pair of plates disposed in the housing such that one of the pair of nested protrusions is spaced apart from and opposite another of the pair of nested protrusions to define a tortuous path that terminates at an outlet defined along an outer circumference. The first chamber is downstream from the pair of plates. The muffler includes a first tube fluidly coupled to the first chamber to direct the exhaust gases from the first chamber to the second chamber. The muffler includes a second tube fluidly coupled to the second chamber to direct the exhaust gases from the second chamber to the third chamber.

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 apparatus and methods are provided for a turbocharger intake system for an off-road vehicle. The turbocharger intake system comprises a turbocharger disposed at a rear of an engine of the vehicle, such that heat radiated from the turbocharger is directed rearward of the engine during operation of the vehicle. The turbocharger is coupled with an exhaust manifold for conducting exhaust gases from the engine to the turbocharger. An air intake duct is routed from an intake air filter canister to the turbocharger for conveying filtered air to the turbocharger. A suitable air filter is housed within the intake air filter canister so as to remove airborne particulate matter from the air entering the engine. The turbocharger drives charged intake air through an intercooler for lowering the temperature of charged intake air. The charged intake air is directed to combustion chambers of the engine by way of an intake manifold.

A pillar shaped honeycomb structure includes: a porous partition wall that defines a plurality of cells, the cells forming flow paths for a fluid, the cells extending from an inflow end face to an outflow end face; and an outer peripheral wall located at the outermost circumference. At least a part of surfaces of the partition walls has a surface layer, and the surface layer includes magnetic particles and has permeability.

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.

In one aspect, a system is provided and includes an engine including an exhaust valve, an exhaust manifold downstream of the exhaust valve and a muffler downstream of the exhaust manifold. The system also includes a catalyst positioned downstream of the exhaust valve.

A selectively tunable exhaust noise attenuation device includes a body having an outer surface and an inner surface that defines an exhaust volume. An inlet is coupled to the body and fluidically connected to the exhaust volume. A first outlet is coupled to the body and fluidically connected to the inlet and selectively fluidically connected to the exhaust volume and a second outlet coupled to the body and fluidically connected to the exhaust volume. A first conduit including a primary exhaust gas flow path directly fluidically connects the inlet and the first outlet. A second conduit includes a first end and a second. The second conduit defines a secondary exhaust gas flow path. A valve is fluidically connected to one of the first and second conduits. The valve is arranged laterally off-set of the primary exhaust gas flow path.

An exhaust gas treatment device, which includes an outer layer, an inner layer that is at least in part disposed within the outer layer, and a loose-fill insulation disposed in the volume between the outer layer and the inner layer, where a piece of fiber mat is disposed between the outer layer and the inner layer and forms a barrier that at least partially prevents the loss of the loose-fill insulation from the volume between the outer layer and the inner layer and a manufacturing method that includes placing a loose-fill insulation into the volume of space between an inner layer and an outer layer and positioning a piece of fiber mat between the outer layer and the inner layer to form a barrier that at least partially prevents the loss of the loose-fill insulation from the volume of space between the outer and inner layers.

An exhaust gas duct system for an internal combustion engine includes an upstream, first exhaust gas pipe area (30), a downstream, second exhaust gas pipe area (34) adjoining the first exhaust gas pipe area (30) in a transition area (38) in an exhaust gas flow direction (G), and a liquid drain channel area (60) in the transition area. The drain channel area is open from the exhaust gas flow volume (78) in the first exhaust gas pipe area (30) or/and in the second exhaust gas pipe area (34) to a liquid collection volume (80).