After achieving the goal of improving engine "breathing", the Superquadro engineers turned their attention to the next challenge: to attain an engine calibration that optimally combines the high-performance delivery with regular operation achieved by reducing the cyclic dispersion of combustion. To obtain this, Ducati introduced a system of secondary air that completes oxidisation of the unburnt hydrocarbons, effectively reducing the levels of carbon dioxide and carbon monoxide (CO). The system is controlled by an electronic valve commanded by the engine control unit and is activated according to the specific condition of engine operation. This valve makes it possible to let in the exhaust pipe of each cylinder head (in a position slightly downstream of the exhaust valve) a flow of clean air originating directly from the airbox. A second reed valve located in the engine head makes this flow unidirectional. The controlled inlet of oxygen makes it possible to complete the combustion of outgoing hot gases, eliminating eventual fractions of unburnt fuel which in certain conditions can reach the exhaust.
