AEM 30-71XX Infinity Stand-Alone Programmable Engine Mangement System Full Manual User Manual
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© 2014 AEM Performance Electronics
Infinity User Manual
Lambda Feedback Min Load [kPa]:
Lambda feedback is disabled below this manifold pressure. Sometimes useful for setups
with aggressive camshaft or very short exhaust piping where exhaust reversion can cause
'false lean' measurements when cruising at very low manifold pressures. If using decel fuel
cut, it may be useful to set this value to the same value as the Decel Cut Below MAP
value.
Min value = 0, Max value = 700
Lambda Feedback Max Load [kPa]:
Lambda feedback is disabled above this manifold pressure. Some tuners prefer to run
open loop without lambda feedback above a certain MAP pressure.
Min value = 0, Max value = 700
Advanced Setup:
Lambda Control Proportional Gain:
Proportional control is a pure gain adjustment acting on the magnitude of the target error
to provide the system response. The advantage of a proportional-only control is it can
respond quickly to large errors; when the error is large the proportional response will be
large. The disadvantage of proportional gain for idle control is the proportional response
will decrease to zero as the measured Lambda value gets closer to the target lambda,
and excessive Proportional gain can sometimes result in 'hunting' lambda values near the
target. Since most tuners want to hit their lambda target and stay there, it is recommended
to rely more heavily on the Integral feedback gain and leave Proportional gain at lower
values. If the system responds too slowly to quick disturbances or large errors, increase
this value slightly.
Min value = 0.000, Max value = 0.500
Lambda Control Integral Gain:
Note that the integral gain is adjusted in the table LambdaFB_I, which adjusts the integral
gain based on Engine Speed. It is recommended to adjust the LambdaFB_I table before
adjusting the Proportional or Derivative values. More details in the
section.
Lambda Control Derivative Gain:
The derivative term adjusts the feedback based on how quickly the target error changes.
Derivative control is used to reduce the amount of overshoot that may occur due to the
Proportional gain's response to large errors. For instance, if the Lambda1 value is below
the target but increasing toward the target quickly, the Derivative term will decrease
feedback to avoid a possible overshoot. In this example, larger derivative gains would
result in larger negative feedback. When the lambda value increases more slowly, the
Derivative contribution will decrease. Note: For most setups, it is recommended to leave
the Derivative gain set to zero.
Min value = 0.000, Max value = 0.100
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