Remote ECU tune · 2.5L EJ257 turbo flat-4
A custom Stage 1, 2 or 3 calibration for your Subaru WRX STI 2.5T (EJ257), built by hand by a real tuner from your own stock file and datalog, and back with you within three hours of the file arriving. We tune these cars remotely, worldwide: you read and flash with your own HP Tuners interface, and you pay only once the tune is delivered.
Stock vs tuned
From the factory the Subaru WRX STI 2.5T (EJ257) makes 305 hp and 290 lb-ft (393 Nm). A Stage 1 tune typically adds 10–25 hp and 44–66 lb-ft, for around 315–330 hp in total. With bolt-ons and a Stage 2 calibration that grows to +15–40 hp, and a Stage 3 build — hybrid / upgraded turbo + injectors / flex fuel — typically lands at 365–455 hp.
| Stage | Added power | Added torque | Total power | Total torque |
|---|---|---|---|---|
| Stock | — | — | 305 hp | 290 lb-ft (393 Nm) |
| Stage 1 | +10–25 hp | +44–66 lb-ft (+60–90 Nm) | 315–330 hp | 334–356 lb-ft (453–483 Nm) |
| Stage 2 | +15–40 hp | +66–96 lb-ft (+90–130 Nm) | 320–345 hp | 356–386 lb-ft (483–523 Nm) |
| Stage 3 | +60–150 hp | +96–148 lb-ft (+130–200 Nm) | 365–455 hp | 386–437 lb-ft (523–593 Nm) |
Typical gains from published dyno results; your car will vary with fuel, mods and conditions.
Supported versions
HP Tuners lists 1 Subaru WRX STI 2.5T (EJ257) entry covering 2008–2020. Interface: MPVI2 or newer.
| Years | Model / engine as HP Tuners lists it | Controller | Credits | Interface |
|---|---|---|---|---|
| 2008–2020 | STI | Engine | 4 | MPVI2/2+/3/4 |
Support data per HP Tuners' supported-vehicle list (June 2026). Check your exact car on HP Tuners' vehicle list before you buy credits.
Stages & prices
One flat price per stage, the same for every car: $250 for Stage 1, $450 for Stage 2 and $650 for Stage 3. Ordering is free and you pay only once the finished tune is delivered. 2 free revisions are included with every order. Gearbox (TCM) shift tuning is included wherever your car's transmission controller can be accessed.
Software only. Every map in the engine ECM is recalibrated for the Subaru WRX STI 2.5T (EJ257) as it sits today — spark, fuelling, throttle response and limiters — against the datalog you send.
For a Subaru WRX STI 2.5T (EJ257) with bolt-ons fitted — intake, exhaust, headers or downpipe, and an intercooler where the car has one. The airflow and fuelling are rebuilt around the hardware you actually have.
Stage 3 on the Subaru WRX STI 2.5T (EJ257) means hybrid / upgraded turbo + injectors / flex fuel. The fuel, spark and boost maps are written from scratch for your exact combination.
Typical gains from published dyno results; your car will vary with fuel, mods and conditions.
Before you order
How it works
FAQ
Typically 10–25 hp and 44–66 lb-ft (60–90 Nm) over the stock 305 hp, for around 315–330 hp in total. Typical gains from published dyno results; your car will vary with fuel, mods and conditions.
An HP Tuners interface (we recommend the MPVI4), the HP Tuners credits needed to license the engine ECM for writing, and your stock file plus a datalog of a drive. You read and flash the car yourself; we build the calibration.
Your custom tune is delivered within three hours of your stock file arriving. Six tuners work three shifts, so a file that lands in the middle of the night is picked up just as fast.
Stage 1 is $250, Stage 2 is $450 and Stage 3 is $650, flat. Ordering is free and you pay only once the finished tune is delivered. 2 free revisions are included with every order.
Stage 3 on the Subaru WRX STI 2.5T (EJ257) means hybrid / upgraded turbo + injectors / flex fuel. The maps are written from scratch for your build, and typical results are 60–150 hp over stock. Typical gains from published dyno results; your car will vary with fuel, mods and conditions.
