RC Flash
2002–2021

Subaru WRX & STI (EJ20 / EJ25) ECU tune

EJ engines reward careful calibration and punish lazy ones. We tune from your logs with knock, fuel trims and boost control in view, and we're honest about ringland risk on stock pistons: the goal is a car that's quicker and still running next year.

Engine
EJ205 / EJ255 / EJ257
ECU
Denso / Hitachi (RomRaider- & EcuFlash-compatible)
Years
2002–2021
Fuel
91–93 octane, E85 with supporting fuel hardware

What we calibrate

Setups we build for

Emissions equipment stays in and working. Every file is versioned against your vehicle with a byte-exact revert.

How it works

  1. 01

    Send your read

    A full read with a Tactrix OpenPort (EcuFlash) or your flashing tool, and logs once you're running the base file.

  2. 02

    We build the file

    Identified, mapped and calibrated on our own stack, with checksums repaired, against your hardware and fuel.

  3. 03

    Flash, log, revise

    Write the file, send logs back. Revisions run in the same ticket until it is right.

Subaru WRX & STI (EJ20 / EJ25) tune pricing

Stage 1

$399

Stock or bolt-ons. One revision included.

  • /Full calibration
  • /1 revision
  • /3 business day turnaround

Stage 2

$599

Downpipe, intake, intercooler. Your fuel target.

  • /Full calibration
  • /2 revisions
  • /5 business day turnaround

Custom / E85

$899

Built from your logs against your exact hardware.

  • /Iterative calibration
  • /4 revisions
  • /Direct tuner thread

Subaru WRX & STI (EJ20 / EJ25) tuning questions

Do you do e-tunes?

That's exactly what this is: you flash, log, send the logs, and we revise in the same ticket until it's right.

What tool do I need?

A Tactrix OpenPort 2.0 with EcuFlash covers most EJ cars. If you have another tool, tell us which.

Do you remove emissions equipment?

No. Catalysts, sensors and monitors stay in and working.