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STI MY16 — Stage 3 ECU Tune

2016 EJ25 E85 AWD Stage 3
kW
106 164
+58
HP
142 220
+78
Nm
191 301
+110
Subaru
STI · 2016
Photo withheld for client privacy
Vehicle
Make
Subaru
Model
STI
Year
2016
Series
MY16
Engine
EJ25
Drive
AWD
ECU
Factory
Tune
ECU Tune
Fuel & Boost
Fuel Type
E85
Modifications
High Pressure Fuel Pump Fuel Injectors Boost Solenoids Wastegate Drive By Wire calibration
Improvements
  • 55% increase in peak power output
  • 58% increase in peak torque delivery
  • Optimized boost control and solenoid response
  • Enhanced fuel system pressure and injector precision
  • Improved throttle response via drive-by-wire recalibration
Full E85 EJ25 build with fuelling and DBW dialled in

This MY16 STI came in as a complete Stage 3 build — high-pressure fuel pump, larger injectors, upgraded boost solenoids and wastegate, all on E85. The job was to calibrate the factory ECU to support the hardware and deliver usable power for circuit work.

The result: 164 kW at the wheels, up from 106 kW, with torque climbing from 191 Nm to 301 Nm. Drive-by-wire throttle mapping was reworked to keep throttle response predictable under load, which matters when you're managing torque delivery on a circuit.

E85 gave us the headroom to lean into the fuelling upgrades without walking into detonation. The calibration prioritises consistency over peak numbers — repeatable pulls, stable AFRs, no surprises mid-corner.

Common questions
Why factory ECU on a Stage 3 build?

The factory ECU has enough headroom to support full bolt-on builds when calibrated properly. It keeps the OEM integration intact while allowing precise control over fuelling, ignition, and boost strategy on E85.

Is this file suitable for street use?

This calibration is intended for off-road and closed-circuit competition use only. The power and torque gains reflect a full build with supporting hardware.

What was involved in the Drive By Wire calibration?

DBW mapping was adjusted to maintain linear throttle response under the higher torque output, preventing abrupt transitions that can unsettle the car during aggressive cornering or throttle modulation.

Workshop & Dealer Access

Protunes supplies ECU calibration files exclusively to approved workshops, tuners, and dealers throughout Australia. Platform: Factory.

Apply for Workshop Access