Challenger Fuel Pump Upgrade: When and What to Install

Stock Fuel Pump Flow Rates

| Model | Fuel Pump | Approximate Max Support |

|---|---|---|

| 5.7L R/T | ~90 L/hr | ~450 whp |

| 6.4L Scat Pack | ~95 L/hr | ~550 whp |

| 6.2L Hellcat | ~145 L/hr | ~750 whp |

| 6.2L Redeye | ~180 L/hr | ~900 whp |

When a build exceeds these thresholds, the fuel pump runs at maximum duty cycle and can't maintain fuel pressure under WOT. The result: lean condition, detonation, and engine damage.

Symptoms of Insufficient Fuel Pump

• Fuel pressure drops under WOT (requires a fuel pressure gauge or data logger to confirm)
• Power drops off in the top end of a pull
• Lean spikes on wideband O2 (if monitored)
• Engine pulls timing from knock sensor response

Upgrade Options

In-Tank Pump Replacement (R/T, Scat Pack):

Drop-in high-flow pumps (Walbro, Deatschwerks, Aeromotive):

• 450 L/hr pump: Supports 600–700 whp on E85
• 525 L/hr pump: Supports 800+ whp

These install in the factory fuel pump module, preserving the factory sending unit.

Hellcat Redeye Fuel System Swap:

The most popular upgrade path for Hellcat owners pushing past 750 whp is swapping in the Hellcat Redeye's larger fuel pump and module assembly. This is a direct swap and plug-and-play with a tune.

Dual Pump Setups:

For high-power builds (900+ whp), some builders add a second in-tank pump or an external lift pump feeding a surge tank.

Fuel Lines

At extreme power levels, the factory fuel lines (3/8" on most models) can restrict flow. Upgrading to -6AN or -8AN lines increases capacity for builds over 800 whp.

E85 and Fuel Pump Demands

E85 requires approximately 30% more fuel volume than gasoline for the same power output. A pump adequate for 600 whp on 93 octane is only adequate for ~460 whp on E85. Factor this in when sizing your fuel system.