4 | Prepare Data Base
34/76 Engine_Control_Unit_MS_6.x_Manual Bosch Motorsport
4.1.3 Initial Steps
The following data must be set initially to start injection calibration for the first time.
Main Data Labels to configure for firing order and engine design
DISPLACEMENT Displacement of all cylinders
CYLBANK Cylinder allocations bank 1 or bank 2
Example typ. 8 cyl. engine:
Cylinder 1 2 3 4 5 6 7 8 9 10 11 12
CYLBANK 1 1 1 1 2 2 2 2 0 0 0 0
Engines with one Lambda sensor (e.g. 4-in-a-row) run as 1-
bank-systems
Set CYLBANK to 1.
CYLNUMBER Number of cylinders
CYLANGLE Angle of cylinder TDCs relative to reference mark (RM →
TDC)
CWINJMODE Selection of injection mode
QSTAT Static valve quantity for n-heptane in g/min (injectors are
typically measured with n-heptane)
TDTEUB Battery voltage correction low-pressure injection. Character-
istics can be requested at the injector valve manufacturer.
TECORPRAIL Battery voltage correction high-pressure injection. Charac-
teristics can be requested at the injector valve manufacturer.
4.1.4 Basic Path of Injection Calculation
The ECU MS 6 is a so called physically based system. This means in particular that correc-
tions are made according to their origin influence (e.g. air temperature, fuel pressure etc.).
For it, the initial engine load signal (throttle angle ath) or the engine charge signal rl (rel-
ative load) is defined as 100 %, if the cylinder is filled with air of 20°C and 1013 mbar
("standard condition"). Corrections related to the air path (air temperature, ambient pres-
sure) are therefore performed to this value rl. Based on this central value most of the rel-
evant ECU signals are calculated, first and foremost injection and ignition.
Due to this constellation changes in the air path are centrally considered for all following
functions, independently whether they are caused by ambient influences, mechanical
changes of the intake system or even a change from alpha/n-system to p/n-system.
Using this rl value, a relative fuel mass rfm is constructed. For an operating point of rl =
100 %, a fuel amount of 100 % is needed, if the desired Lambda = 1. All corrections to the
desired fuel quantity like start enrichment, warm up factor, transient compensation, but
also the desired Lambda value and the correction factor of the Lambda control are con-
sidered as an adjustment of this relative fuel mass. I.e. all corrections are still made inde-
pendently of the size and other specifications of the injectors.
Next step is the conversion of the relative fuel mass to a desired injection time te. Here
the engine´s displacement, the fuel flow through the injector and influences of the fuel
pressure are considered.
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