Spool Performance Stage 4 FX400X Upgraded High Pressure Fuel Pump [B58 Gen 2]

The Spool Performance Stage 4 FX400X High Pressure Fuel Pump is the ultimate fueling solution for BMW B58 Gen 2 engines. Delivering 350 bar (35 MPa / 5000 psi), the FX400X improves upon the industry-leading FX350 by approximately 20% across the entire delivery range, providing unmatched performance for high-horsepower builds.

When paired with Spool’s IFX350 Gen2 direct injectors, the FX400X enables record-breaking DI-only horsepower numbers, making it a revolutionary upgrade for Gen2 BMW fuel systems. The pump is fully plug-and-play and includes all necessary lines, mounting hardware, and tools for a clean, straightforward installation.

Designed with precision and durability in mind, the FX400X is eligible for Spool Performance’s lifetime warranty program. Proper tuning is required to operate the pump, and Spool’s team can assist with tune adjustments across supported platforms.

Fueling capability highlights:

• With FX400X + IFX350 Gen2 Injectors:
  • Gasoline: 1100whp
  • E50 Mix: 900whp
  • E85: 800whp
• With FX400X + IFX150 Gen2 Injectors + Spool Cam Lift Mod:
  • Gasoline: 1200whp
  • E50 Mix: 1050whp
  • E85: 900whp

This pump requires proper low-pressure fueling to operate safely. Although the FX400X is covered under Spool Performance’s lifetime warranty, cavitation-induced damage to the piston or bore is excluded. Upgrading your low-pressure fuel system is strongly recommended for optimal performance and reliability.

FITMENT
BMW B58 Gen 2 3.0L Turbocharged Inline-6 Engine (2018+)
Compatible with models including:

• BMW G20 330i / M340i
• BMW G22 / G23 440i / M440i
• BMW G29 Z4 M40i
• BMW G21 / G21 XDrive 340i
  Designed for direct injection high-pressure fuel systems (DI HPFP)

Key Features

• Spool Performance Stage 4 FX400X high-pressure fuel pump
• 350 bar (35 MPa / 5000 psi) maximum fuel delivery
• 20% improvement over FX350 across entire flow range
• Revolutionary DI-only high horsepower support with IFX350 Gen2 injectors
• Plug-and-play installation with included bracket, alignment tool, and lines
• Triple-layer low-pressure line: Nylon over stainless steel over PTFE
• Plug-and-play HPFP adapter harness included
• Lifetime warranty program (excludes cavitation damage)
• Requires tuning adjustments; Spool team can assist
• Supports gasoline, E50, and E85 fueling applications
• Optimized for B58 Gen 2 high-horsepower BMW builds

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.