Spool Performance BMW S58 Auxiliary Split Fuel System

Spool Performance BMW S58 Auxiliary Split Fuel System

The Spool Performance BMW S58 Auxiliary Fuel System is engineered for enthusiasts pushing beyond the limits of the factory fueling system. Built with proper fuel architecture, this system separates direct injection (DI) and port injection (PI) supply to deliver stable, predictable fueling at higher power levels while maintaining a clean, OEM-style installation.

Every component is designed for real-world usability, long-term reliability, and consistent performance as your build evolves.

Why a Split DI + PI Fuel System Matters

As power increases on the S58 platform, combining DI and PI on a single fuel feed creates instability:

• DI pulse cycles can introduce pressure fluctuations affecting PI injectors
• PI requires boost-referenced pressure for consistent fueling
• Higher boost and airflow make fuel delivery less predictable

By separating DI and PI supply:

• Each system operates independently
• Fuel pressure remains stable under load
• Fuel delivery becomes consistent and repeatable at high power levels

Key Features

• True split DI and PI fuel system architecture
• Retains OEM fuel pump top hat using precision aluminum fittings
• Plug-and-play wiring harness compatible with Reflex controller
• Dual Walbro 450 fuel pumps included
• Optional Walbro 525 fuel pump upgrade available
• Choice of standard relay or solid-state relay (PWM control)
• Compact, boost-referenced fuel pressure regulator
• Triple-layer PTFE fuel lines for durability and ethanol compatibility

Clean OEM-Style Installation

• No repinning or modification of factory wiring required
• Direct integration with OEM fuel pump top hat
• Optional billet top hats available separately
• Designed for clean, factory-like fit and finish

High-Quality Fuel System Components

• PTFE inner core for full fuel and ethanol compatibility
• Stainless steel reinforcement for high-pressure strength
• Nylon outer layer for abrasion resistance
• Built for high-heat, high-vibration environments

Scalable Performance

• Dual Walbro 450 pumps support high horsepower builds
• Optional Walbro 525 pumps for more demanding setups
• Flexible control options for precise fuel delivery
• Designed to grow with your build

Performance Benefits

• Stable and consistent fueling at high boost
• Improved reliability for high-performance applications
• Better fuel pressure control under load
• Supports large turbo and port injection setups
• Maintains drivability while increasing fuel capacity

FITMENT

BMW M3 (G80) – 2021+
BMW M3 Touring (G81) – 2023+
BMW M4 (G82 / G83) – 2021+
BMW M2 (G87) – 2023+
BMW X3 M (F97) – 2020–2024
BMW X4 M (F98) – 2020–2024

Additional Notes:

• Designed specifically for S58 engine platforms
• Professional installation recommended
• Compatible with Reflex controller systems
• Ideal for high-performance street and track builds

Upgrade your BMW S58 with the Spool Performance Auxiliary Split Fuel System for maximum fueling control, scalability, and reliability as your build reaches higher performance levels.

Note: 'New' merchandise may be returned for exchange or refund within 15 days from the date of shipment. 'New' merchandise must be unused and free from installation or mounting damage. Installation or modification of parts waives your right to returns, refunds, or exchanges.