5 Series E60 M5 (S85) SAL
Vacuum supply
In some operating situations the low air pressure required for the brake power assistance is insufficient. This
particularly applies if the catalytic converter is heated up when the engine is cold. An electric vacuum pump
generates the low air pressure which is required. The DME switches the vacuum pump on or off as required.
The switching thresholds depend on the speed.
Oil supply
4 oil pumps are responsible for the oil supply.
Owing to the engine's dynamism and extreme acceleration performance, an unusually complex oil supply
system is required.
The oil pump housing contains 2 oil pumps.
The pendulum slide cell pump delivers the exact volume of oil which is required by the engine. The inner rotor
(pendulum slide) is mounted on sliding bearings. The volumetric flow control is dependent on the oil pressure in
the main oil gallery.
The oil sump is split into two parts. During heavy braking, the oil will possibly not run out of the front oil sump
back into the rear oil sump.
The second oil pump in the oil pump housing draws the oil from the front oil sump into the rear oil sump. This
ensures that the oil supply will be maintained during heavy braking.
During extreme cornering, a high lateral acceleration is produced which forces the engine oil into the cylinder
head on the outside of the curve. 2 electric oil pumps ensure that the oil supply is maintained. The oil pump on
the outside of the curve draws the engine oil from the cylinder head into the rear oil sump.
The DSC sensor reports the lateral acceleration to the DME via the PT-CAN.
Fuel supply system
The following specific demands are placed on the S85B50 fuel system:
•
Fuel delivery with high dynamics
•
Lower level of fuel vapour in the tank due to reduced heating of fuel
•
Minimised current consumption of fuel pumps with improved charge balance and subsequent reduced fuel
consumption
A demand-oriented fuel supply with a variable fuel delivery pressure meets these requirements.
The fuel delivery pressure is adjusted as a function of the engine load. A fuel-pressure sensor measures the fuel
delivery pressure. The signal is sent to the DME.
The fuel delivery pressure varies between approximately 2.5 and 6 bar.
The 2 fuel pumps are connected hydraulically in parallel.
The fuel pumps are activated by a separate fuel pump output stage. The DME control module activates the fuel
pump output stage.
To do this, the DME control module sends a pulse-modulated signal to the fuel pump output stage. The fuel
pump output stage controls the first fuel pump according to demand (also by means of PWM signal).
The maximum permissible deviation for the cycle ratio between the incoming and outgoing PWM signals is 3%.
This tolerance applies throughout the entire service life of the electric fuel pumps.
If a cycle ratio of 98% is achieved at the input for the fuel pump output stage, the second fuel pump is also
connected without regulation (higher load range).
During this process, the system pressure is restricted to 6 bar by the mechanical fuel-pressure regulator in the
fuel tank.
Exhaust system
SBT S85B50 engine E60, E61 M5 E63, E64 M6
BMW AG - TIS
23.02.2013 19:29
Issue status (12/2007) Valid only until next DVD is issued
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