Engine Performance Calibration - Bosch ECU MS 25 Sport Manual

Bosch Motorsport

5 Engine Performance Calibration

Summary of basic Diesel engine calibration:
– The correct calibration for the beginning of injection angle is one of the most import-
ant things. A good calibration will make the engine powerful, economical and reliable.
– In case the injection angle is calibrated too early (big values), this will cause high /
early cylinder peak pressures, which can damage/crack the piston!
– In case the injection angle is calibrated too late (small values), this will cause very high
exhaust gas temperatures, which may damage the turbocharger!
The most important information to calibrate the beginning of injection angle correctly is
cylinder pressure indication! The cylinder pressure indication system is a stand-alone sys-
tem and this it is not part of the MS 25 Sport system provided by Bosch. If recommenda-
tions for a cylinder pressure system are needed, please contact Bosch Motorsport for fur-
ther information.
While optimizing the performance calibration the following values need to be monitored
very carefully so that their respective limits are not exceeded:
– Cylinder pressure
– Exhaust gas temperature
– Turbocharger speed
– Torque limitation given by engine mechanics (based on material properties of e.g.
crankshaft, bearing forces, cylinder head gasket etc...)
– All the other engine parameters which could have a destructive impact such as
coolant temperature tmot, oil pressure poil, oil temperature toil and so on
Basic engine calibration targets are:
– Reliable engine start without big overshoots in engine speed when low idle speed
setpoint is reached for the first time
– Stable engine operation in low idle controller with minimal oscillations and good in-
jection quantity pre control coming from the friction map so that there is only small
PID controller interference
– Good rail pressure build-up during engine start until rail pressure setpoint is reached
– Stable rail pressure control at rail pressure setpoint suitable for the hydraulic com-
ponents
– Fast reaction of rail pressure to changes in the rail pressure setpoint with minimal
over- / undershoots when the setpoint is reached
– Max. boost pressure setpoint adapted to the given engine configuration.
– Stable boost pressure control at boost pressure setpoint
– Full load optimization with main injection angle, fuel quantity calibrated for the given
engine configuration
– Smoke limitation appropriately calibrated to ensure a fast engine reaction without
high smoke opacity
– Limitation of engine speed to the maximum allowed value in combination with a fit-
ting cut in engine speed of the high idle controller
Engine Control Unit MS 25 Sport
Engine Performance Calibration | 5
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