DME Control Unit DFI EMS SDI 3.1

DME Control Unit DFI EMS SDI 3.1

The new 911 Turbo features the highly efficient engine management system EMS SDI 3.1. Compared with the Motronic ME 7.8.1 used in the past, the completely newly developed Digital Engine Management EMS SDI 3.1 has a greater processing power with a tripled clock rate and a memory capacity increased by approx. 65 %. The control unit has been specially designed to meet the requirements relating to direct fuel injection (DFI) and VarioCam Plus.

Of particular significance here is control of the injectors, since these are the central elements of the direct fuel injection system. Compared with intake manifold injection, direct fuel injection requires an engine management system with additional functions and significantly faster data processing. Controlling the injectors with multiple injection and an extensive data map are particularly complex tasks.

The modern engine management system EMS SDI 3.1 allows sequential injection of fuel into the combustion chamber for each cylinder at precisely defined time intervals. This contributes to minimizing fuel consumption and reducing emissions even in dynamic driving operation. Each cylinder receives precisely the amount of fuel that corresponds to the engine load condition in order to realize the optimum air/fuel ratio.

Main tasks and control functions:
- Direct fuel injection (DFI)
- Fuel supply
- DFI injectors
- Ignition system
- Electronic throttle
- VarioCam Plus
- Variable oil pump
- VTG turbocharger
- On-board diagnosis (OBD II)

Other DME functions and control functions:
- Fuel supply, low-pressure side/high-pressure side
- Load detection via pressure sensor (on intake manifold)
- Boost pressure detection by pressure sensor (upstream of electronic throttle)
- Individual ignition coils with integral drivers
- VarioCam Plus of intake camshafts Adjustment 0 to 40° crank angle, valve lift 3.6 & 10 mm
- Control of VTG turbochargers
- Control of the demand-controlled oil pump
- Electric coolant pump for turbochargers
- Secondary-air pump
- Control of the 2 steplessly adjustable radiator fans
- Control of the engine compartment purge fan
- Demand-based increase in idle speed to increase the generator power

In the new 911 Turbo, a pressure sensor in the intake manifold is used for detection of the air flow (load detection), which is also used as a basis for determining the required fuel injection quantity. Compared with the hot-film mass air flow sensor (MAF sensor - downstream of the air cleaner) used in the previous model and the current 911 Carrera models, load detection via a pressure sensor offers lower flow losses.