Ignition - main table, Motec calibration 45 – MoTeC M84 User Manual

Page 47

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MoTeC Calibration

45

closest to the current engine operating point. The Quick Lambda feature may
only be used if the ECU is directly measuring the Lambda reading. The
desired Lambda value must be set in the Functions - Lambda Control
Table
.

If the maximum value in the table falls below 60 then the setup parameter
IJPU should be decreased to increase the table values. This ensures that the
table has sufficiently fine resolution. Similarly, if the table values reach the
maximum table value then the IJPU setup parameter should be increased to
decrease the table values.

Use the F5 key to change quickly between the Fuel - Main Table and the
Ignition - Main Table.

Use the F6 key to change quickly between the Fuel - Main Table and Fuel -
Timing Table.

Use the View - Fuel Screens to check that all the fuel trims and
compensations are correct (press the V key).

Refer to the ECU Manager software help for more details (Press F1).

Ignition - Main Table

The Ignition - Main Table allows adjustment of the Ignition Timing at various
RPM and Load points.

Start with a conservative curve for the particular engine, not too advanced and
not too retarded.

Use extreme caution when adjusting the Ignition Timing to ensure that the
engine does not knock due to excessive advance. Re-check the Ignition
Timing with a Timing Light to ensure that what the ECU thinks is the ignition
advance is in fact the actual advance.

The Ignition Timing should be adjusted for maximum torque without knocking,
by increasing the advance until the torque stops increasing. Make sure there
are at least 3 or 4 degrees margin to the knock limit.

Too much retard will cause excessive exhaust gas temperature.

At idle, a more retarded ignition setting is desirable (approximately 10 to 15
degrees). This makes the idle speed less sensitive to load changes. Also the
ignition should be flat over the idle RPM range so that timing variations do not
cause the engine to hunt, since variations in the timing will vary the engine
torque.

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