Abstract: Methods and systems are provided for controlling imbalance with an exhaust tuning valve. In one example, a method may include adjusting a first exhaust tuning valve in response to combustion torque imbalance in a first and second group of cylinders. Additionally or alternatively, the position of the second exhaust tuning valve may be adjusted in response to an imbalance generated by the same group of cylinders.

Abstract: 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.

Abstract: The disclosed inventive concept provides a further achievement in efforts to produce a tunable exhaust sound for a vehicle. The system provides a tunable exhaust system including a tunable resonator and a pair of tunable mufflers. The tunable resonator includes a housing including first, second and third expansion chambers. A pair of bank-by-bank exhaust conduits extends through the housing. At least one of the conduits includes a band of peripheral perforations within the first expansion chamber. The band is formed at an angle relative to the long axis of the conduit on which it is formed. The mufflers include inlet and outlet pipes. At least one of the outlet pipes includes a variable exhaust gas flow assembly. The variable exhaust gas flow assembly includes a vane shaft, an exhaust gas regulating vane attached to the vane shaft, and a vane actuator for regulating the position of the vane shaft.

Abstract: 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.

Abstract: The disclosed inventive concept provides a further achievement in efforts to produce a tunable exhaust sound for a vehicle. The system provides a tunable exhaust system including a tunable resonator and a pair of tunable mufflers. The tunable resonator includes a housing including first, second and third expansion chambers. A pair of bank-by-bank exhaust conduits extends through the housing. At least one of the conduits includes a band of peripheral perforations within the first expansion chamber. The band is formed at an angle relative to the long axis of the conduit on which it is formed. The mufflers include inlet and outlet pipes. At least one of the outlet pipes includes a variable exhaust gas flow assembly. The variable exhaust gas flow assembly includes a vane shaft, an exhaust gas regulating vane attached to the vane shaft, and a vane actuator for regulating the position of the vane shaft.