Engine & Power · Buyer's Guide

Fuel Rails

High-flow billet rails replace stock plastic ones; required for serious forced-induction builds and aftermarket injectors over ~80 lb/hr.

Recommended Picks

A starting point for your build, sorted by budget.

All Fuel Rails (9)

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19. FUEL SYSTEM — INJECTORS AND PUMPS

When Do You Need Upgraded Injectors?

  • Stock 5.7L injectors: ~24 lb/hr — sufficient for stock and mild bolt-ons
  • Stock 6.4L injectors: ~30 lb/hr — sufficient for Stage 1–2, marginal at Stage 3 NA
  • Stock 6.2L Hellcat injectors: ~62 lb/hr — sufficient for stock boost, upgrade needed for pulley + power mods

Rule of thumb: Injectors should be sized at 80% duty cycle max. At 100% duty cycle, you're "running lean" at the top end. For a supercharged build, calculate needed injector size: HP ÷ BSFC ÷ number of injectors × safety margin.

Injector Size Guide by Build

Build Level Target HP Injector Size
Stock / Stage 1 bolt-ons Up to 500 HP Stock size (no change)
Stage 2 + mild cam 500–600 HP 60 lb/hr (DeatschWerks)
Supercharged (mild boost) 600–750 HP 1000cc (DeatschWerks, ID)
Supercharged (aggressive) 750–900 HP 1100cc–1500cc
E85 flex fuel builds Any HP 1300cc+

Key Brands

  • DeatschWerks: Most popular HEMI injector brand. Every unit is matched on a flow bench before shipping. 1000cc, 1100cc, 1500cc options for HEMI. Direct drop-in fit.
  • Injector Dynamics (ID): Premium matched injectors. ID1050x is popular for supercharged builds.
  • Mopar/OEM-size options: Good for mild builds where you just want direct replacement quality

When Do You Need an Upgraded Fuel Pump?

The stock in-tank pump flows approximately 255 l/hr — fine for naturally aspirated up to ~500 HP. Under boost or at high RPM with aggressive injectors, the pump becomes the bottleneck.

Pump options:

  • DeatschWerks DW300 (340 l/hr, drop-in replacement) — best value direct-fit pump upgrade
  • Walbro 450 LPH — high-output option for high-boost builds
  • Fore Innovations Triple Pump Hat — for extreme builds 900+ HP where one pump isn't enough
  • Boost-A-Pump (BAP) — increases voltage to stock pump temporarily under boost; band-aid solution but works for mild setups

Flex Fuel / E85 Notes

E85 ethanol has lower energy density than gasoline but higher octane (~105 RON). Running E85 requires:

  • Injectors sized ~30% larger than gasoline-only equivalents
  • Fuel pump capable of higher volume
  • E85-compatible fuel rails and lines
  • Custom tune for E85 fueling tables
  • Flex fuel sensor (if running pump gas + E85 blend)

On E85, a supercharged HEMI can see 30–50+ HP over the same pump-gas tune due to higher octane and charge cooling from ethanol evaporation.

Site UX Recommendations

  • Injector sizing calculator concept: "Enter your target HP and engine → see recommended injector size"
  • "Required with supercharger" badge on injectors and pumps in the context of SC kits
  • E85 compatibility clearly marked on fuel parts that support it