Abstract: An exhaust manifold 14 extending downwardly is connected to a rear side of a transversely disposed engine E. A primary exhaust pipe portion 16 is connected to the exhaust manifold 14 via a spherical joint 18 provided close to the engine E. Furthermore, a secondary exhaust pipe portion 17 is connected to the primary exhaust pipe portion 16. In the primary exhaust pipe portion 17, a flexible tube 19 is disposed at a position upstream of a support portion to the vehicle body.

Abstract: An exhaust manifold 14 extending downwardly is connected to a rear side of a transversely disposed engine E. A primary exhaust pipe portion 16 is connected to the exhaust manifold 14 via a spherical joint 18 provided close to the engine E. Furthermore, a secondary exhaust pipe portion 17 is connected to the primary exhaust pipe portion 16. In the primary exhaust pipe portion 17, a flexible tube 19 is disposed at a position upstream of a support portion to the vehicle body.

Abstract: An exhaust passage control valve has a valve element of a spiral shape mounted on a valve seat portion of a housing through which exhaust gases from an engine pass. The valve element is urged by a valve spring in a direction of closing the valve. A spring constant of the valve spring is kept low without enlarging the valve spring, and there can be obtained opening and closing characteristics in that the valve opens at a stretch when an exhaust-gas pressure has reached a predetermined value. As the valve spring, a helical torsion spring having a coiled cylindrical body portion is used. Arm portions on both ends of a coiled cylindrical body portion are engaged with a pair of spring receiving members. The spring receiving members are disposed in the housing on circumferentially opposite sides of the valve seat portions. The arm portion are engaged with the spring receiving members so as to be slidable in a longitudinal direction of the arm portions.

Abstract: An exhaust passage control valve has a valve element of a spiral shape mounted on a valve seat portion of a housing through which exhaust gases from an engine pass. The valve element is urged by a valve spring in a direction of closing the valve. A spring constant of the valve spring is kept low without enlarging the valve spring, and there can be obtained opening and closing characteristics in that the valve opens at a stretch when an exhaust-gas pressure has reached a predetermined value. As the valve spring, a helical torsion spring having a coiled cylindrical body portion is used. Arm portions on both ends of a coiled cylindrical body portion are engaged with a pair of spring receiving members. The spring receiving members are disposed in the housing on circumferentially opposite sides of the valve seat portions. The arm portion are engaged with the spring receiving members so as to be slidable in a longitudinal direction of the arm portions.

Abstract: The case of an intake silencer system includes a first case half and a second case half coupled to each other at mating faces, with an intake duct clamped between the mating faces. The intake duct opens into a resonant chamber within the case, so that noise is damped by a resonant effect. Three ribs are provided on an inner surface of the first case half, thereby defining four subsidiary silencing chambers each functioning as a side branch for producing a resonant effect to obtain a silencing effect in a wide frequency range. The ribs also contribute to an enhancement in rigidity of the wall surfaces of the case.