912 Models

In addition to the above, 1969 912 models incorporate a distributor equipped with a vacuum control unit which retards ignition timing at idle speeds. Because of retarded timing, throttle valves can be opened slightly farther at idle speeds, allowing cylinders to receive a greater supply of air. To improve fuel atomization, intake ducts are heated with warm air.

Fig 1: Porsche Transducer

Courtesy of PORSCHE CARS NORTH AMERICA, INC.