Edelbrock 3670 User Manual - page 180
180
5.5
Adaptive Fuel "AutoTuning" Capabilities
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Adaptive Fuel "Auto Tuning"
Capabilities
In addition to (or instead of) adaptation of airflow (VE) with MAF sensor/s in Speed/
Density mode, the system can be setup to run single or dual approved switching OR
wideband oxygen sensors in all control modes: Alpha-N (speed/throttle), MAP-N (Speed/
Pressure), or true Speed/Density modes. The oxygen sensor provides feedback on the
engine's current air/fuel ratio, which provides the ECU with the data needed for
adaptation of the fueling in order for the system to deliver the calibrated air/fuel ratio.
Oxygen Sensor Adaptation & Interface
The driver's side sensor is always the
primary
sensor.
Always plug into the driver side only
when using a single sensor. If using dual sensors, the passenger's side sensor values are
averaged into the compensation calculations. If dual sensors are used and one sensor fails, or
goes into a fault condition - the system will automatically revert to the known good sensor.
As with adaptation of volumetric efficiency when using a mass airflow sensor, the oxygen
sensor will constantly adapt the fueling model to compensate for small changes in fuel
delivery or airflow, providing the engine with an air/fuel ratio equal to the mapped value.
The fueling will be adapted with or without mass airflow: mass airflow is not
required to run closed loop, as the fueling adaptation routine is separate from
the airflow adaptation.
As the engine runs, the O2 sensor will provide feedback to the ECM. This feedback is
compared with what the ECM is commanding. Any difference between the two is
calculated and adapted out as the engine runs. This will not only help the engine run at
the desired AFR, it will also let the tuner enter actual AFR values and not simply fuel
pulse width in speed/density mode. (Alpha-N / MAP-N modes also adapt in closed loop;
however, Alpha-N or MAP-N mode requires that the base fuel pulse width values be
calibrated to deliver air:fuel ratios that are closer to your mapped air:fuel target values,
so that the difference between mapped and actual is within the adaptive range of the
system. You also want to have the mapped values very close to actual to minimize
abrupt transitions or surging when the system goes in and out of closed loop during