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Best Subaru WRX Mods: VA, VB, and STI Build Paths
Plan Subaru WRX modifications in the right order with separate daily-driver, handling, power, and track paths for the VA WRX, VB WRX, and VA STI.
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Know the car.
Build it better.
Vehicle-specific research for understanding engines, diagnosing problems, planning maintenance, and choosing modifications that fit.
Vehicle libraries
Start with your platform
Find the guides written for your chassis, engine, and generation.
63 guides
Subaru WRX / STI
Engines, reliability, maintenance, tuning, and chassis-specific upgrades.
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9 guides
BRZ / FR-S / 86
Handling, forced induction, exhaust, tires, and driver-focused upgrades.
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4 guides
Nissan 350Z
Z33 suspension, exhaust, tires, and VQ35DE engine guides.
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4 guides
Nissan 370Z
Z34 suspension, exhaust, tires, and VQ37VHR engine guides.
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2 guides
Subaru Crosstrek
Tires, lift kits, and practical upgrades for street and trail use.
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The WRX knowledge base
Follow the Subaru WRX from its EJ-powered generations through the FA20DIT and FA24DIT. Our growing library connects engine identification, common problems, service planning, tuning, and fitment-specific upgrades.
Explore all 63 WRX guides
Step 1
Understand Your Engine
Identify the engine in each generation and follow the right technical guides.
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Step 2
Research Reliability
Compare common problems by generation before buying or diagnosing a WRX.
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Step 3
Plan Maintenance
Build a service plan around the correct generation, engine, and transmission.
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Step 4
Plan Your Build
Follow separate daily, handling, power, and track paths for the VA, VB, and STI.
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Technical library
Browse by what you want to do
Move between vehicles through the systems and decisions that matter.
Engines
Specifications, variants, applications, and known problem areas.
Maintenance & Reliability
Service planning, ownership costs, and model-specific reliability.
Tuning
Calibration methods, supporting hardware, fuel, and power paths.
Handling
Suspension, alignment, brakes, wheels, and tires for the intended use.
Intake & Exhaust
Fitment, sound, tuning requirements, and practical tradeoffs.
Auto Detailing
Paint correction, washing, drying, and protection guides.
WRX tuning guides
Build the right combination
Start with the build path, then follow the stage, Green Speed, and Accessport guides that determine which parts and maps fit together.
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? WRX Owner's Tuning Guide (2026)
COBB Project Green Speed changed Accessport maps, emissions-code adjustments, j-pipe support, and flex fuel. See what still works for WRX owners in 2026.
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.
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