Bosch MS 6 - Engine Speed Limitation and Cutoff Patterns

4 | Prepare Data Base
38/76 Engine_Control_Unit_MS_6.x_Manual Bosch Motorsport
Main Data Labels for engine speed limitation
CWNMAX_CUTOFF Codeword for type of intervention during soft limiter:
0 = only ignition retard
1 = injection cutoff
2 = ignition cutoff,
3 = injection and ignition cutoff
CWNMAXH_CUTOFF Codeword for type of intervention during hard limiter:
1 = injection cutoff
2 = ignition cutoff,
3 = injection and ignition cutoff
NMAX_GEAR Engine speed limit, gear dependent
NMAX_P Determines the slope of the soft limiter between soft limit
and hard limit.
Predefined. Vary according to your engine´s dynamic beha-
vior.
TC_GEARNMAXPR Prediction time for rev limiter, depends on the inertial
torque of the engine. If oscillations occur, reduce value or
turn off by setting = 0.0.
4.1.11 Main Data Labels for Cutoff Pattern
Cutoff Pattern
MP_COPATTERN Defines the appropriate cylinders for torque reduction by
cylinder cutoff.
At the beginning of an intervention the next possible cylin-
der for starting the cutoff pattern is determined. Based on
this info the actual pattern is taken out of the map.
Pattern should be defined in view of minimized oscillations
of the crankshaft.
Usually a regular distribution of firing and non-firing cylin-
ders leads to the best result. However, investigations of the
individual engine are recommendable.
For it, cutoff pattern can be also turned on manually via
CUTOFF_APP and CWCUTOFF_APP
Example: 4-cylinder engine
Start Cyl./Cutoff stage 1 2 3 4
1 1 (=0001b) 2 (=0010b) 4 (=0100b) 8 (=1000b)
2 9 (=1001b) 6 (=0110b) 6 (=0110b) 9 (=1001b)
3 11 (=1011b) 14 (=1110b) 7 (=0111b) 13 (=1101b)
4 15 (=1111b) 15 (=1111b) 15 (=1111b) 15 (=1111b)
The cylinders are assigned bitwise, the lowest bit represents
cylinder 1.
Numbering refers to mechanical cylinders, e.g. pattern = 9:
Mechanical cylinders 1 and 4 are fade out.