Starting up the ECU | 4
Bosch Motorsport
Engine_Control_Unit_MS_3_Sport_GT3_Cup_Manual
13 / 24
Example 1
To better understand this process a symmetrical 6 cylinder engine with a standard crank-
shaft wheel will be described. The first TDC is 78° from the second tooth after the gap. In
this case the following parameters must be input:
Parameter
Ignition power stage identification
CYLNUMBER = 6
-
CRANKWHEEL36 = 0
-
TDCCYL1 = 78
A
TDCCYL2 = 198
B
TDCCYL3 = 318
C
TDCCYL4 = 438
D
TDCCYL5 = 558
E
TDCCYL6 = 678
F
Notice that the angle between each TDC is 120° because the engine has symmetrical igni-
tion.
Example 2
Now suppose the same engine has a V configuration 90°-150°. In this case the TDC angles
are:
Parameter
Ignition power stage identification
CYLNUMBER = 6
-
CRANKWHEEL36 = 0
-
TDCCYL1 = 78
A
TDCCYL2 = 168
B
TDCCYL3 = 318
C
TDCCYL4 = 408
D
TDCCYL5 = 558
E
TDCCYL6 = 648
F
4.1.2 Injection
The label INJCALC contains parameters to calibrate the fuel injection time.
The base injection time parameter TI_DEF is influenced by many correction parameters
mentioned below to optimize combustion.
TI_DEF
Base injection timing in milliseconds
The injection time depends mainly on throttle position, engine speed, fuel pressure and
injection valve type. To get a first estimation, the following characteristics must be known:
– displacement per cylinder V
C
(m
3
)
– expected intake manifold pressure (after throttle) p
i
[Pa]
– desired lambda value λ
– operating fuel pressure p
f
[bar]
