Cobb 04-07 Subaru STI / 02-07 WRX / 04-08 FXT 3-Port Boost Control Solenoid

Part Details:

The COBB 3-Port Boost Control Solenoid for the 2004–2007 Subaru STI, 2002–2007 WRX, and 2004–2008 Forester XT is designed to provide more precise and consistent boost control compared to the factory 2-port solenoid. By allowing the ECU to directly control boost pressure with greater accuracy, this upgrade supports improved turbo response and stable power delivery under load.

This 3-port configuration allows for finer boost tuning adjustments when paired with proper ECU calibration. It is commonly installed alongside turbo upgrades, intake modifications, and custom tuning to optimize boost curves and reduce inconsistencies such as boost spikes or creep.

Key Features

• 3-port boost control design for improved boost accuracy
• Enhanced turbo response and stable pressure regulation
• Direct-fit application for supported Subaru models
• Designed for use with proper ECU tuning calibration
• Supports higher boost levels compared to factory solenoid

What’s Included

• COBB 3-port boost control solenoid
• Vehicle-specific mounting hardware
• Pre-assembled vacuum lines and fittings
• Installation instructions

Frequently Asked Questions

Is tuning required after installation?
Yes. Proper ECU tuning is required when installing a 3-port boost control solenoid to ensure safe air-fuel ratios and correct boost targeting.

What is the advantage over the factory solenoid?
The factory 2-port solenoid has limited control authority at higher boost levels. A 3-port design provides more precise boost regulation and improved consistency.

Is this compatible with stock turbo setups?
Yes. It can be used on stock or upgraded turbo systems, provided appropriate tuning is performed.

Recommended Supporting Forced Induction Components

• Blow Off Valves – help manage excess boost pressure and protect the turbo system under load.
• Intercooler Kits – reduce intake air temperatures and support consistent boost performance.
• Turbochargers – pair with precise boost control for optimized airflow and power output.
• Wastegates – regulate boost pressure and maintain stable turbo system operation.
• COBB Tuning Performance Products – explore additional tuning and turbo system upgrades from COBB.
• Subaru WRX Performance Parts – browse compatible upgrades for WRX turbo platforms.
• Subaru STI Performance Parts – discover supporting turbo components for STI builds.
• Subaru Forester XT Performance Parts – find boost control and turbo system upgrades for Forester XT models.