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

THIS PRODUCT IS CURRENTLY ON BACKORDER. CONTACT US AT CUSTOMER_SERVICE@SPOOLPERFORMANCE.US IF YOU HAVE ANY QUESTIONS.

Spool Stage 4 FX400X HPFP – Because “Enough Fuel” Is a Myth

So you’ve maxed out your stock fuel system, your tuner is sending passive-aggressive logs, and your car leans out harder than your gym phase in 2019.

Congratulations — you’ve reached the point where normal people stop.
This is not for those people.

The Spool FX400X is what happens when “just one more upgrade” turns into four-digit horsepower goals and questionable life decisions.

It doesn’t ask if you need this much fuel.
It assumes you’ve already committed to chaos.

💀 What This Pump Is Really For

• Making your tuner slightly less stressed

• Running ethanol like it’s water

• Supporting power levels your tires will absolutely hate

• Flexing on anyone still pretending their stock pump is “fine”

🔧 Specs (a.k.a. The Overkill Section)

• Max Pressure: 350 bar (~5000 psi)

• Flow Increase: ~20% over FX350

• Power Support:

  • ~1100 WHP (gas)

  • ~900 WHP (E50)

  • ~800 WHP (E85)

• Potential: ~1200 WHP with supporting mods

• Compatibility: B58 Gen 2 engines

• Install: Plug & play (emotionally not plug & play)

⚠️ Requirements (Read This Before You Cry Later)

• Custom tune (obviously)

• Upgraded LPFP (seriously, don’t skip this)

• Supporting mods to match your bad decisions

• A tuner who answers texts after midnight

👍 Why You “Need” It

• Your current pump is crying

• You said “I’ll stop at 600whp” and didn’t

• You like living on the edge of fuel trims

• You want DI-only fueling without going port injection (for now…)

👎 Why You Don’t

• You still have a stock turbo (please leave)

• You enjoy financial stability

• You think 500whp is “plenty”

🧠 Final Verdict

This isn’t an upgrade.
This is a commitment to the problem.