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.

A damper valve assembly includes a valve housing, a valve flap and a torsional spring. The valve housing is adapted to be attached to a pipe of an exhaust system and defines an opening. The valve flap is rotatably coupled to the valve housing about a pivot axis. The valve flap is movable between a first position whereat fluid flow through the opening of the valve housing is restricted and a second position whereat fluid flow through the opening of the valve housing is allowed. The torsional spring engages the valve flap to bias the valve flap toward the first position. A preload of the torsional spring when the valve flap is in the first position is adjustable.

A damper valve assembly for an exhaust system of a vehicle includes a valve housing and a valve flap. The valve housing is adapted to be attached to a pipe of the exhaust system and defines an opening. The valve flap is rotatable relative to the valve housing and about a pivot axis between a first position whereat fluid flow through the opening of the valve housing is restricted and a second position whereat fluid flow through the opening of the valve housing is allowed. The valve flap includes a body and a mass damper. The mass damper is integral with the body and includes a plurality of segments that are folded so that the plurality of segments are in a stacked arrangement.

An exhaust muffler includes a first muffler section connected to an exhaust pipe and a second muffler section connected to the first muffler section. 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 first muffler section includes a tubular member made up of an inner pipe to which the exhaust pipe is connected and an outer pipe covering the inner pipe, and a connector connecting the tubular member and the second muffler section to each other. The first muffler section has a first expansion chamber defined therein between the inner pipe and the outer pipe. The inner pipe houses therein a valve for changing an amount of exhaust gases passing through the inner pipe. The first muffler section includes a curved portion that is curved vertically as viewed in side elevation of the vehicle. The exhaust muffler has a second expansion chamber defined in the second muffler section rearward and upward of the first muffler section, the second expansion chamber having a cross-sectional area larger than a cross-sectional area of the first expansion chamber. There is thus provided an exhaust device for an internal combustion engine, which includes a muffler compact in a longitudinal direction thereof.

A damper valve assembly for an exhaust system of a vehicle includes a valve housing and a valve flap. The valve housing is adapted to be attached to a pipe of the exhaust system and defines an opening. The valve flap is rotatable relative to the valve housing and about a pivot axis between a first position whereat fluid flow through the opening of the valve housing is restricted and a second position whereat fluid flow through the opening of the valve housing is allowed. The valve flap includes a body and a mass damper. The mass damper is integral with the body and includes a plurality of segments that are folded so that the plurality of segments are in a stacked arrangement.

Methods and systems are provided for enhancing and delivering engine sounds to a vehicle cabin based on a selected mode. In one example, a method may include adjusting openings of one or more valves fluidically coupling one or more corresponding engine regions to a sound tube of a sound enhancing system based on the selected mode. Throttle opening may also be adjusted to compensate for air routed from the engine regions to the sound tube instead of flowing to the engine cylinders.

Methods and systems are provided for diagnostics of an exhaust tuning valve during vehicle-off conditions. In one example, the engine may be reverse rotated, unfueled while the position of the exhaust is varied and an intake air flow is estimated at each position of the exhaust tuning valve. The exhaust tuning valve may be diagnosed based on a change in air flow with the variation in the position of the exhaust tuning valve.

An exhaust system for an internal combustion automotive engine, comprising: a left exhaust tract connected or to be connected to a left group of cylinder of the internal combustion automotive engine and a right exhaust tract connected or to be connected to a right group of cylinder of the internal combustion automotive engine, the left and right exhaust tracts, each comprising a branching structure defining a tract inlet, at least one exhaust outlet directly or indirectly opening into atmosphere, and an interconnecting outlet interconnecting said left and right exhaust tracts, wherein said interconnecting outlets are interconnected with each other by a common exhaust gas cleaning and/or silencing device downstream said interconnecting outlets such that exhaust gas flows coming from said interconnecting outlets are unified within said common exhaust gas cleaning and/or silencing device.

An exhaust-gas system for a vehicle having an internal combustion engine includes a Helmholtz resonator and two exhaust-gas lines extending toward the resonator. The resonator has two neck openings to a resonator volume. Each neck opening is coupled to one of the exhaust-gas lines, and the resonator is tuned to damp a dominant engine order.

Exhaust systems for handling multiple effluent streams are described. Some embodiments include pressure drops to prevent perturbations from one effluent source from affecting a second effluent source. Some embodiments incorporate an exhaust assembly with multiple inlets and pumps and a single outlet. The exhaust assembly includes shared auxiliary components like purge and cooling systems.