The exhaust system is an innovative "variable design," featuring twin mufflers with vacuum-actuated valves that open above a specified back pressure. When these valves open, a portion of the exhaust gases is routed through a second set of tail pipes pointed at the ground. This design offers numerous advantages. It allows the engine to be calibrated to produce higher torque. Secondly, it provides a free-flowing exhaust system, while still providing the capability for passing mandated pass-by noise regulations in the U.S., Canada, and U.K. Thirdly, it makes for some lovely exhaust sounds at wide-open throttle. The exhaust side of the engine also features a full 2 ½ inch stainless steel exhaust system, running from the exhaust manifold outlet to the tip of the exhaust pipes.