STi MY13 — Stage 2 ECU Tune
- Consistent 44 newton-meters torque increase across entire RPM range
- Boost stability correction
- Enhanced engine control management
This MY13 STi came in for a service and dyno session after the owner reported erratic boost behaviour. We tracked it down, sorted the instability, and optimised the torque model to bring the calibration into line with how the car was actually breathing.
The result is 163 kW and 355 Nm at the wheels, up from 148 kW and 305 Nm. The 50 Nm torque lift is the real story here—makes a noticeable difference on road and track when you're on the throttle mid-corner or climbing out of second.
Stage 2 keeps things sensible for a daily driver that sees weekend circuit use. The EJ25 responds well to proper boost control and a dialled torque strategy, especially once you've ironed out the instability that was holding it back.
What was causing the boost instability?
Not specified in the workshop notes, but it was identified and rectified during the session. Common culprits on these cars include vacuum leaks, wastegate actuator drift, or boost control solenoid faults.
Is this suitable for daily driving?
Yes. Stage 2 with basic supporting mods keeps the EJ25 reliable for road use while offering meaningful improvements in torque and drivability. The torque model optimisation helps maintain smooth delivery.
What does torque model optimisation actually do?
It recalibrates the ECU's internal prediction of engine load and torque output so fuelling, ignition timing, and boost targets align with the engine's true airflow. Improves response and consistency, particularly after hardware changes.
Workshop & Dealer Access
Protunes supplies ECU calibration files exclusively to approved workshops, tuners, and dealers throughout Australia.
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