On the 911 Turbo models, DFI injects the fuel with millisecond precision directly into the combustion chamber at up to 140 bar via electromagnetically actuated injection valves, thus ensuring homogeneous distribution of the air/fuel mixture and consequently efficient combustion.
In the direct injection system, the EMS SDI 3.1 engine management system adjusts the injection timing individually for each cylinder and the injection quantity for each cylinder bank. This optimises both the combustion curve and fuel consumption.
Dual injection is implemented at engine speeds of up to 3,200 rpm and triple injection up to 2,700 rpm to ensure faster catalyst warm up after a cold start and more torque in the upper load range. The required quantity of fuel is distributed to two or three successive injection processes per cycle.
DFI improves the internal cooling of the combustion chamber by forming the mixture directly in the cylinder. This has made it possible to increase compression (9.8: 1), resulting in more engine power and even greater efficiency.