Cobb Fuel Rails + Line Kit Package Subaru STI 2008-2021 | SUB000FRLK

Part Details:

The COBB Fuel Rails & Fuel Line Kit Package is designed to improve fuel delivery consistency and support higher-demand setups on Subaru STI models from 2008–2021. By replacing restrictive factory fuel rails and lines, this kit helps ensure balanced fuel distribution across all cylinders—an essential foundation for performance tuning and ethanol-based fuel systems.

Precision-engineered for direct fitment, the system features high-quality fuel rails and upgraded fuel lines capable of handling increased flow and fuel pressure. This makes it an ideal upgrade for vehicles running flex fuel, upgraded injectors, or higher horsepower calibrations where consistent fueling is critical for safe and repeatable performance.

Fueling Stability for High-Performance Builds

Uneven fuel distribution can become a limiting factor as power levels increase. The COBB fuel rail and line package addresses this by improving cylinder-to-cylinder fuel balance, helping maintain stable air-fuel ratios under load. This is especially important for STI builds targeting increased boost, ethanol blends, or aggressive tuning strategies.

Compatibility & Integration

This kit is engineered to integrate seamlessly with other COBB fuel system components, including upgraded injectors and flex fuel setups. Installation maintains OEM-level fit and finish while providing the headroom required for future power upgrades.

Key Features

• Direct-fit fuel rail and fuel line upgrade for Subaru STI 2008–2021
• Improved fuel flow and cylinder-to-cylinder fuel distribution
• Designed to support ethanol blends and high-performance tuning
• High-quality fuel rails, fittings, and lines for durability under increased fuel pressure
• Compatible with COBB fuel system components and Accessport-based tuning
• Ideal foundation for flex fuel and upgraded injector setups

What’s Included

• COBB fuel rails
• Upgraded fuel lines
• Required fittings and installation hardware

Frequently Asked Questions

Is this fuel rail kit required for flex fuel?
While not always mandatory, upgraded fuel rails and lines are strongly recommended for flex fuel and higher horsepower setups to maintain consistent fuel delivery and safe operation.

Does this kit support upgraded injectors?
Yes. This package is designed to work with upgraded injectors and is commonly paired with higher-flow injector setups on performance STI builds.

Is tuning required after installation?
Yes. Any fueling system upgrade should be followed by proper ECU tuning to ensure correct fuel calibration.

Recommended Supporting Fuel Components

• Fuel Injectors – higher ethanol content often requires increased fuel flow to maintain proper air-fuel ratios.
• Fuel Pumps – support the additional fuel volume needed for ethanol and higher power levels.
• Fuel Pressure Regulators – help maintain consistent fuel pressure across varying ethanol blends.
• Fuel Delivery Components – explore supporting fuel system parts designed to work together.

Learn more about COBB Tuning performance solutions and supporting components