Car Tuning Technology Guides

COBB Accessport for Subaru WRX: Our OTS-to-E-Tune Experience

See how a COBB Accessport changed our 2017 Subaru WRX, from a MAPerformance Stage 1 map to a custom e-tune, plus what to know before choosing maps and parts.

WRX E-Tune vs. Dyno Tune: Which Custom Tune Is Better?

Compare a Subaru WRX e-tune with an in-person dyno tune by process, safety, cost, power, drivability, and fit for VA, VB, and STI builds.

How Does a WRX E-Tune Work? Subaru E-Tuning Guide

Learn how a Subaru WRX e-tune works, including base maps, Accessport datalogs, map revisions, required equipment, completion time, and safety.

How Does a WRX Dyno Tune Work? Complete Guide

Learn how a Subaru WRX dyno tune works, from the pre-tune inspection and baseline pull through ECU changes, validation, cost, and the final dyno graph.

EcuTek WRX Tuning: Compatibility, Costs, and COBB Comparison

Learn how EcuTek tuning works on supported Subaru WRX models, what the license and interface do, and how EcuTek compares with a COBB Accessport or Atlas.

WRX Open-Source Tuning: Atlas for VA and VB Subaru WRX

Learn how open tuning works on the VA and VB Subaru WRX, including Atlas, compatible cables, ECU flashing, datalogging, COBB differences, and safety limits.

Stage what? WRX Stages 1, 2, and 3 explained.

Learn what WRX Stage 1, Stage 1+, Stage 2, Stage 2+, and Stage 3 mean after COBB Project Green Speed, including VA, VB, STI, CVT, and custom-tune differences.

COBB Project Green Speed: What It Means for WRX Tuning

COBB Project Green Speed changed WRX downpipe support, DTC deletes, flex fuel, and Stage 2 packages. Learn what still works in 2026.

WRX Flex Fuel Guide: Best CAN Flex Fuel Kits for VA and VB WRX

WRX flex fuel is back through COBB CAN Flex Fuel for supported VA and VB WRXs. Here is what changed after Green Speed, which kits fit, and what to verify before running ethanol.

Subaru's Knock Correction Made Simple

If your Subaru WRX, WRX STI, Forester XT, or other turbocharged model is tuned and you have a Cobb AccessPort, you probably monitor some parameters related to knock, or at least have heard that you should. While many owners are worried when they see any knock, this isn't always a concern. In this article, we'll explain how Subaru's knock control system works, and how the various parameters are related.

Best Subaru WRX Mods: VA, VB, and STI Build Paths