DME Engine Electronics 3.6 L V6 DFI Engine
DME Engine Electronics 3.6 L V6 DFI Engine
The main changes in the new Cayenne 3.6 l V6 DFI compared with the previous model are described on the following pages.
Contents
- General
- DME control unit V6 DFI, Bosch MED 17.1.6
- New and modified DME components and functions
- Fuel supply, low-pressure side
- Fuel supply, high-pressure side
- Ignition system
- Intake system / Hot-film mass air flow sensor HFM 7
- Exhaust system / Emission control
General
An enhanced V6 naturally aspirated engine with direct fuel injection (DFI) is used for the new Cayenne. Thanks to improved efficiency and the use of the latest engine technology, it was possible to significantly reduce the fuel consumption compared with the previous model and ensure that all world-wide emission standards are met.
Development goals
- High engine power
- High maximum torque
- Low fuel consumption
- Low emissions
Enhancements
- Thermal management
- Auto Start Stop system (Tiptronic S)
- Variable deceleration fuel cutoff
- Vehicle electrical system recuperation
- Dethrottling of the intake system
Engine specifications for Cayenne 3.6 l V6 DFI naturally aspirated engine (10.6° V)
DME control unit Bosch MED 17.1.6
Displacement 3.6 liters
Power 300 hp/6,300 rpm
Torque 400 Nm/3,000 rpm
Compression ratio 11.65 (-0.5)
Idle speed 650 rpm Max.
engine speed 6,700 rpm
VarioCam Int. 52° / Exh. 32° crank angle
Firing order 1-5-3-6-2-4
CO2 emissions 236 g/km (Tiptronic S)
The engine is based on the 3.6 l V6 DFI naturally aspirated engine familiar from the previous model. The focus of development was not just on optimizing fuel consumption and performance, but also on detailed measures designed to enhance running smoothness and comfort during operation. In addition to the requirement of complying with all worldwide emission regulations and significantly reducing fuel consumption, the development goal for the 3.6 l engine was to increase both power output and torque. The increase in power by 10 hp to an total output of 220 kW/300 hp at 6,300 rpm and the higher maximum torque of 400 Nm (+15 Nm) at 3,000 rpm were achieved by a number of different measures.
NOTE: Function descriptions for the specified DME functions can be found in the part of this section dealing with the V8 engines.
DME control unit V6 DFI, Bosch MED 17.1.6
The DME control unit MED 17.1.6 was adapted for the following new functions of the V6 engine:
- Thermal management
- Auto Start Stop function (in combination with Tiptronic S)
- Variable deceleration fuel cutoff
- Vehicle electrical system recuperation
- Differential Hall sensor on the crankshaft
- Control unit for electric fuel pump
The high-performance electronic engine control unit MED 17.1.6 from Bosch is used for the 3.6 l V6 engine. This control unit has been specially designed to meet the requirements relating to direct fuel injection and VarioCam. Of particular significance here is control of the injectors, since these are the central elements of the direct fuel injection system. The engine control also controls the throttle valve position (electronic throttle) - this is a prerequisite for the Porsche Stability Management (PSM) system installed as standard.
The modern DME control unit allows sequential injection of fuel into the combustion chamber for each cylinder at precisely defined time intervals. This contributes to minimising 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.
The newly implemented thermal management, variable deceleration fuel cutoff and realisation of the Auto Start Stop function in combination with the new 8-speed Tiptronic S also contribute to further-enhanced efficiency.
As a result, the new Cayenne with standard manual transmission achieves a combined fuel consumption improvement of approx. 10% compared with the previous model. In combination with the optional Tiptronic S, the fuel consumption is approx. 20% lower than the previous model.
New and modified DME components and functions
Thermal management
The three main areas of thermal management are temperature control and heat distribution between:
- Combustion engine
- Passenger compartment and
- Tiptronic S
Goals
- Bringing components to the optimum operating temperature quickly (reduced friction)
- Reduced engine and transmission friction through map-based control of the operating temperature
- Meeting the comfort requirements of passengers
NOTE: Further function descriptions for the specified DME functions can be found in the part of this section dealing with the V8 engines.
Function
he main parts of the coolant system that have been modified for thermal management are a water pump that can be switched off by way of a split ring slide valve, a variable-flow coolant after-run pump as well as shut-off valves in the water guide to the heating heat exchanger and to the transmission oil/water heat exchanger.
Two temperature sensors are installed in the engine cooling system to control the thermal management system, one is installed in the cylinder head at the front left in the direction of travel and the other is located in the coolant collector on the engine block.
Auto Start Stop function
On all new Cayenne models with 8-speed Tiptronic S (optional for Cayenne), the Auto Start Stop function can be activated and deactivated by way of a button in the center console.
Variable deceleration fuel cutoff
- Enhancement of conventional deceleration fuel cutoff
- Interruption of fuel supply in deceleration condition, e.g. when driving downhill
- After a phase with deceleration fuel cutoff, fuel injection is resumed variably depending on the driving situation, which may correspond to an even lower engine speed.
Vehicle electrical system recuperation in communication with gateway control unit
Among other things, this control operation includes the DME control unit, the gateway control unit, the brake pedal sensor, starter battery with battery sensor, the generator and the vehicle electrical system.
Differential Hall sensor V6
The new Cayenne V6 also has a new differential Hall sensor for detection of the:
- engine speed
- reference mark and
- direction of rotation of the engine
The function descriptions for the specified DME functions can be found in the part of this section dealing with the V8 engines.
- Sport button as standard
- Off-road mode
- Control of VarioCam intake and exhaust camshaft
- 1 steplessly controlled radiator fan Cayenne V6 - MT- 0 to 600 W, AT- 0 to 850 W
- Communication with control unit of adaptive cruise control (ACC), acceleration or deceleration via electronic throttle and where appropriate braking, also to vehicle standstill
- Increase in idle speed
The idle speed can be increased when the engine is warm if a request is received from the gateway in order to increase the charging current of the generator. The field current is regulated in the gateway.
NOTE: A function description is provided in the part of this section on V8 engines and in the section Electrics "Gateway".