Why did we change it?

Subaru controls the timing of their fuel injection events for Direct Injected (DI) engines using Start of Injection (SOI) timing control, which defines when the injection event should begin on each engine cycle relative to crankshaft positioning. These tables were previously available to Protuners for editing under the "Beta" table label. The display conversion for these SOI values from native ECU units into human-readable units was previously estimated to be approximately correct, but still required further analysis over time using on-car data to verify. We now have a finalized corrected version of this conversion that allows for viewing the most accurate SOI values in both the Accesstuner Pro (ATP) software and associated datalogs.

For the 2022+ WRX, this has the additional benefit of enabling SOI values of greater than 360 degrees during the calibration process. This limit was previously problematic for properly optimizing the DI system for elevated power levels and/or fuel flow requirements, and a misfire behavior may have been observed as SOI values approached 360 degrees on 2023+ vehicles.

Changes

The SOI tables available for editing are the same as before, but they are now displayed using the updated conversion. This will make an old map that has been re-opened in the new ATP software to appear to have "different" SOI values, but the underlying values are unchanged and will not be changed unless they are further manipulated within the software. Re-opening the map in the new software will allow for proper editing of the new values, as will using the Import / Import Tables from Comparison functionality. Manually copy and pasting the data between old and new maps/software will cause issues and should not be done.

This will also facilitate continued datalog review and calibration refinement for customers who have yet to update their Accessport (AP) and do not yet have access to the new monitors (listed below). Updating to the latest firmware using Accessport Manager will add the new monitors to the AP's logging capabilities.

ATP and AP Monitors:

The old “Beta” Homogeneous SOI/EOI monitors are renamed as “OLD” (AP names shown). These will be removed in the future:

• Inj Timing H EOI Old

• Inj Timing H EOI Ign Old

• Inj Timing H EOI Ign Time Old

• Inj Timing H SOI Old

The monitors are added and named as “NEW” (AP names shown):

• Inj Timing H EOI New

• Inj Timing H EOI New

• Inj Timing H EOI New

• Inj Timing H EOI New