AlphaN

With the stock code, AlphaN is only used to run the engine if there is a DTC for MAF. So if you want to run AlphaN with the stock code, you must not disable DTC 8. Once you unplug the MAF, you will see a CEL and DTC 8, but the AlphaN tables will get used.

My custom code has a user-configurable byte that can be set to enable MAF or AlphaN without setting a DTC. Also, the table sizes have been greatly expanded for precise tuning of Individual Throttle Bodies.

Application Conditions

IF there is a DTC 8 (MAF) and DTC 12 (TPS), THEN "AlphaN - TPS (DTC 12)"

IF there is a DTC 8 (MAF) only, THEN "AlphaN - TPS"

Calculation

[ ["AlphaN - IACV" x "AlphaN - IACV (TPS Compensation)"] + ["AlphaN - TPS"] ] x "AlphaN - IAT Compensation"

AlphaN logic uses TPS, IACV PWM, and IAT to calculate Load, while MAF logic uses Airflow to calculate Load.

Note - The IACV values used by the AlphaN table axes are slightly different than the normal IACV parameter. AlphaN uses IACV PWM.

AlphaN should never be used with a Turbo or Centrifugal Supercharger. A Roots style or twin-screw Supercharger might be fine to use with AlphaN.

How to tune

1. Begin datalogging Load, RPM, TPS, IACV PWM, and IAT on a good MAF tune

2. Drive vehicle with slow throttle changes until all relevant TPS and IACV PWM values are recorded.

3. Plot of RPM vs IACV PWM (vs Load). Transfer values to "AlphaN - RPM vs IACV"

4. Plot of RPM vs TPS (vs Load). Transfer values to "AlphaN - RPM vs TPS"

Tuning Notes

During AlphaN tuning you are teaching the ECU how to calculate Load is for a given Airflow & RPM. Airflow is affected by TPS, IACV PWM, and IAT.

If engine runs properly on MAF tune at a specific cell (Load vs RPM) but AFR is rich or lean in AlphaN mode:

Then add/subtract Load in AlphaN tables as needed for TPS, IACV PWM, or IAT effects.

Once Load is calculated by Coarse Tuning AlphaN, Fine Tuning Fuel and Timing is the same as before.