Abstract: A passive exhaust valve assembly includes an exhaust conduit or pipe section with a valve plate or vane member that can pivot within the interior section or volume of the exhaust conduit to regulate the flow of exhaust gases through the exhaust conduit. A flexible bumper element, such as a metal mesh pad, may be positioned on the interior surface of the exhaust conduit, such that an end portion of the valve plate may contact the mesh pad in the closed position. The bumper element may be disposed in a recessed pocket or depression and may be biased inward, such as with a spring, for the end portion of the valve plate to contact the bumper element as it moves toward the closed position, and thereby gradually reduce the closure speed of the valve plate to the closed position.