A90/ A91 Toyota Supra Auxiliary Split Fuel System

Spool Performance A90 / A91 Toyota Supra Auxiliary Fuel System

The Spool Performance A90 / A91 Toyota Supra Auxiliary Fuel System is designed for Supra owners pushing beyond the limits of the factory fuel system who want a solution that’s properly engineered, easy to install, and built for long-term reliability.

Built around the B58 platform used in the Supra, this system focuses on correct fuel architecture and real-world usability. Every component and layout choice was made to deliver stable, predictable fueling at higher power levels while maintaining clean OEM-level integration.

Why a Properly Split DI + PI Fuel System Matters

As power levels increase on the B58-powered Supra, fueling challenges typically come from supplying direct injection (DI) and port injection (PI) from the same fuel feed.

When DI and PI share a feed:

• The pulsed nature of DI can introduce pressure fluctuations that disrupt fuel flow to the PI injectors

• Port injection requires boost-referenced fuel pressure to maintain consistent injector differential under load

• At higher boost and airflow, maintaining precise and repeatable fueling becomes more difficult

By separating the DI and PI supply, each system operates independently and exactly as intended. The result is smoother fuel delivery, improved consistency, and greater confidence as power increases—especially on higher-boost Supra setups.

Designed to Install Cleanly on the Supra Platform

Extensive development went into making this system straightforward to install while retaining OEM functionality.

• The OEM fuel pump top hat is retained using additional precision-machined aluminum fuel fittings that integrate directly into the factory top hat, eliminating the need for repinning or modifying factory wiring

• Optional billet top hats are available separately for those who prefer them

• A plug-and-play wiring harness is supplied for direct compatibility with the Reflex controller, simplifying installation and control

The result is a clean, factory-like install that avoids unnecessary complexity.

Scalable Pump and Control Options

The system is designed to grow with your Supra build:

• Dual Walbro 450 fuel pumps included standard

• Optional Walbro 525 upgrades available for higher horsepower goals

• Choice of:

  • Standard relay configuration

  • Solid-state relay option for full PWM pump control

This flexibility allows the fuel system to scale as power levels increase without requiring a complete redesign later.

High-Quality Fuel Plumbing

All fuel lines included in the kit feature triple-layer PTFE construction:

• Inner PTFE core for full fuel and ethanol compatibility

• Middle stainless steel reinforcement for pressure strength

• Outer nylon protective layer for abrasion resistance and durability

Designed to handle aggressive fuels, high pressure, and the heat typical of high-performance Supra builds.

Compact, Purpose-Built Fuel Pressure Regulation

The system includes Spool Performance’s in-house designed compact fuel pressure regulator, developed specifically for auxiliary fuel applications:

• Boost-referenced for accurate pressure control under load

• Stable regulation at high flow rates

• Compact design for clean engine bay packaging

• Built to withstand high heat and vibration

Built for High-Power Supra Builds

Whether you’re building a strong street-driven Supra or a higher-power setup, the Spool Performance A90 / A91 Toyota Supra Auxiliary Fuel System delivers the fueling control and capacity needed to push the platform confidently.

With properly separated DI and PI supply, OEM-friendly integration using precision aluminum fittings, Reflex compatibility, high-quality plumbing, and scalable pump options, this system is engineered to perform reliably as your Supra build evolves.

If you’re ready to take your Supra’s fueling to the next level with a system that’s thoughtfully engineered and easy to live with, this is the solution built to get you there.

Fitment

• Toyota GR Supra

  • A90 Supra – 2020–2021

    • 3.0 / 3.0 Premium (B58 inline-6)

    • 2.0 (B48 inline-4)

  • A91 Supra – 2022–2023

    • 3.0 / 3.0 Premium (B58 inline-6)

    • 2.0 (B48 inline-4)