Subaru Accesstuner Tuning Guide Supplement
For 2.4L DIT WRX
INTRODUCTION
This document outlines some of the unique engine control unit (ECU) logic and tuning strategies relevant to Subaru's 2.4L DIT WRX. It is not the intention of this document to outline every difference but rather the most notable differences (known to date) that can impact your ability to tune effectively. ECU logic for the 2.4L WRX is very similar to the Subaru Ascent and other DIT models.
OTHER RESOURCES
Please refer to the other DIT tuning supplement guides for additional information not described here (where applicable):
Subaru Accesstuner FA24DIT Tuning Supplement
Subaru Accesstuner DIT Tuning Guide Supplement
APPLICABLE SUBARU MODELS
The following Subaru models are applicable to this document:
2022 Subaru WRX 6MT
TABLE DESCRIPTIONS
Besides this document, an additional resource for ECU logic details are the table descriptions shown in the Accesstuner software. These will show up in the lower left corner of the software for the current table that is selected. If not visible, make sure the "Table Description" check box is selected in the View menu. Additionally, the Help menu in the software contains links to documents that list all of these table descriptions as well as all of the data monitor descriptions.
CONTACT US
COBB authorized Protuner are welcome to contact us with any additional questions/concerns or when in need of troubleshooting assistance.
ECU LOGIC CHANGES
LIMITS
The 2.4L WRX has the following notable limits:
Boost reading - this is limited to a max of about 61.5 psig at sea level, not including the hardware limit for the factory MAP sensor (which likely is limited to about 24 psig at sea level). We have included the MAP calibration tables to account for the installation of an aftermarket MAP sensor (keep in mind that the factory sensor is a combination unit that also includes the IAT manifold sensor).
Boost targets - this is limited to a max of about 61.5 psig as sea level when the Boost Targets Max. Limit table is raised from its 24 psi limit.
Load limit - load is limited to just under 4.0 g/rev.
IPW limit - At higher load with richer fuel targets, a hard-coded IPW limit can be hit that will cause IPW to go static in the 7.x ms range and the car to run leaner than expected. This is the same limit that was present in prior DIT that was addressed via the CCF Gen 2 features on the 15-21 WRX. Those features have not yet been applied to the 2.4L WRX ECU.
THROTTLE MAPPING
The 2.4L WRX has some unique changes related to requested torque:
Requested Torque tables are split by the estimated gear position (1st through 6th). A new Gear Position ESTIMATED Req Torque monitor tracks the unique gear position monitor used for table switching.
When transitioning between gears, the Requested Torque (Gear Transition) table is used.