Prosport Performance
Performance headers
Prosport headers are fully constructed out of T304 stainless steel, including the flanges. Their Subaru headers include the up-pipe, which uses their exclusive three-bolt flange design between the manifold and up-pipe providing a stable connection without air leaks. With a jaw-dropping, 45mm inner pipe diameter you can be sure your spent exhaust will exit in a hurry.
MSRP: $529

5Zigen USA
Proracer Header
Born into the rally racing in Japan, ProRacer's full SUS304 header for the EJ20/25 helps the car with weight reduction, engine pickup, and power.
MSRP: $1,250

Simota USA
Carbon-Fiber Intake System
Simota's new line of carbon-fiber intake systems for the '01 and newer Subaru Impreza 2.0 uses twin charger technology and the very best air filters. Simota has engineered this intake to breathe like never before.
MSRP: $295

Cold-Air Intake System
It relocates the filter outside of the engine compartment to deliver the coolest air inlet temperature possible, creating more horsepower and torque. The chassis mounting bracket uses soft rubber mounts that provide a stress-relief point under engine load and prevent the bracket from being ripped out. High-quality hose clamps ease the installation process and securely fasten the intake to the vehicle. CNC-machined MAF adapters provide factory-like fit and prevent check-engine lights.
MSRP: $376.59

Agency Power
Cold-Air Intake Kit
'08 And Newer Subaru WRX STI
Focused on quality, function, and style, Agency Power has developed this intake kit for the '08 and newer Subaru WRX or STI. The intake kit is available as a short-ram or cold-air version. It features a CNC-aluminum MAF sensor mount on the intake tube with built-in fins to keep airflow laminar. The kit gained approximately 10 hp and 10 lb-ft of torque.
MSRP: Starting at $250

Performance Radiator
'08 And Newer Subaru WRX/STI
Mishimoto Automotive Performance has a new all-aluminum performance radiator for the '08 Subaru WRX/STI. Every Mishimoto Performance radiator is crafted out of high-quality and aircraft-quality aluminum, providing you with up to 30 percent more cooling power than standard radiators. The new applications are designed to fit with all OEM specifications to make installation a breeze.
MSRP: $340

APS Engineering
Twin-Scroll Rotated Mount Turbocharger
This comprehensive, rotated mount, bolt-on turbocharger system includes: a twin-scroll liquid-cooled ball bearing turbocharger with custom APS aerodynamic configurations and antisurge, 44mm TiAL external wastegate, and a Precision TIG-welded polished stainless steel twin-scroll up-pipe.

Cobb Tuning
Cobb Tuning offers you the ultimate personal tuning solution for your STI. Save time and money with the ability to conveniently reprogram your vehicle's computer (ECU) by selecting one of the pre-installed performance "maps" that automatically optimizes your settings, like the air/fuel ratio, ignition timing, boost, and more for performance results you can instantly feel. However, the AccessPort is so much more than just a reflash device. It allows you to monitor fuel economy (average and real time), perform performance tests in order to estimate your 0-to-60 and quarter-mile time, read and decipher ECU trouble codes (CELs), and monitor live data through the OEM vehicle sensors, eliminating the need for costly aftermarket gauges.
MSRP: $695

Blouch Performance Turbo
Subaru Dominator 3.0R
The Dominator 3.0R features a state-of-the-art 52 lb/min Garrett GT compressor wheel, a high-efficiency Garrett GT turbine wheel, and a full ball bearing CHRA capable of delivering over 400 whp.
MSRP: $1,695