Table of Contents

3.4 Choosing an AFR Mode


Direct Link Switching AFR mode

An AFR mode must be selected before programming the ECU. When tuning, selecting the "Tuning" AFR Mode is recommended. When finished or evaluating the suitability of a tuning file, selecting the "Final" AFR mode is recommended.

Direct Link Tuning AFR Mode

Tuning AFR Mode using External Wideband Tuning Sensors:

This feature disables the Closed Loop permissions of the ECU by automatically programming all Desired AFR values more than 13.9 to 13.9. (This removes closed loop behavior.) The user defined Desired AFR remains unchanged in the saved calibration file. The Stock O2 sensor information is still available to the ECU, but the ECU does not have the permission to adjust VE table values. This ECU state (Open Loop) is an essential status when tuning.

This is only applicable to motorcycles with Stock O2 sensors and, consequently, motorcycles with Closed Loop system capabilities. The selected mode here will take effect when next programming the ECU. The user defined Desired AFR remains unchanged in the saved calibration file and the motorcycle will be programmed with the Tuning equivalent of that AFR table.


Tuning AFR Mode using Motorcycles Stock Narrowband Fuel Efficiency Sensors:

This feature enables the Closed Loop permissions of the ECU by automatically programming all Desired AFR values 14.3-14.6. This creates a lean target AFR at which the stock sensors can function accurately. As repeated tuning steps bring actual motorcycle conditions closer to these target AFR conditions, the stock sensors become more accurate. Tuning with narrowband sensors becomes more efficient after each successive tuning session and programming. The user should expect 3-4 After a few VE calibration runs, with the stock sensors providing increasingly accurate AFR readings after each run, the user can select the "Final AFR Mode" to put the motorcycle into a more rider friendly fuel state. The selected mode here will take effect when next programming the ECU. The user defined Desired AFR remains unchanged in the saved calibration file and the motorcycle will be programmed with the Tuning equivalent of that AFR table.

Note: Tuning with stock sensors is only applicable to motorcycles with Stock O2 and, consequently, motorcycles with Closed Loop system capabilities.

See "Why tune with Wideband?" section for more information about the difference between Wideband sensors and Narrowband sensors.


Direct Link Tuning Mode Off

Final AFR Mode:

This feature sends the unmodified AFR table to the ECU. A typical TechnoResearch AFR table enables some of the Closed Loop permissions of the ECU set in the Desired AFR table and also puts the motorcycle into a more cruise friendly fuel state.

In Closed Loop ECU has the permission to adjust the cruising range VE table values in accordance to the readings it receives from the Stock Oxygen Sensors to better improve cruising fuel efficiency. This ECU state (Closed Loop) is meant as a Fuel Efficiency mechanism and is incompatible with wideband sensor data collection and tuning. If tuning with wideband sensors, Close Loop or the "Final AFR Mode" should only be activated after the calibration steps are completed.

This is only applicable to motorcycles with Stock O2 sensors and, consequently, Closed Loop system capabilities. The selection here will take effect when next programming the ECU. Closed Loop AFR values and location must be configured prior to using this feature.
The Direct Link software will not engage Close Loop features unless the proper AFR Values are applied to the current calibration.
PLEASE NOTE: If you are an experienced tuner and do not want the Direct Link software to automatically adjust the ECU out of Closed Loop- adjust the tables as desired and select the Final AFR mode. This leaves the tables as the user defined them.