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LS fuel system, E85 & injectors

What the fuel system needs for an LS swap, from stock power to E85 and boost. Size yours with the fuel system calculator.

Key facts

Injector formula: Injector sizing formula (per injector)
Bsfc: BSFC used for sizing (conservative examples)
Duty cycle: Design duty cycle limit (Sources differ: 80% vs 85%)
Pressure scaling: Injector flow vs fuel pressure
E85 stoich: E85 stoichiometric AFR
E85 more fuel: Extra fuel needed on E85 (Many sources quote ~30% (e.g., multiply gasoline injector size by 1.3); the figure depends on the BSFC assumed. Speedway chart E85/gas ratio ≈1.19–1.25)
Methanol: Methanol fuel demand
Impedance: LS injector impedance
Connectors: LS injector connectors
Heights: LS injector heights (Text says 38–64.8 mm; table lists 47.4–67 mm)
Aftermarket range: Aftermarket injector flow range
Decapping: Decapped injectors
Tune required: Tuning
Base pressure: LS base fuel pressure
Pump formula: Fuel pump minimum flow
Pump pressure: Pump flow vs pressure

Used on	Rail bore	Intake bore	Length	Connector	Notes
LS3, LS7, LS9, L76, L77, L98, L99, LS4, LSA, LSX, LS2 (some)	0.533	0.551	1.95	USCAR
Truck (LH6, LY5, LY6, LC9, LFA, L98, L20, L21, LC8, LY2, LM4, L96)	0.533	0.551	1.915	USCAR
Truck (L92, LH8)	0.536	0.551	1.865	USCAR
Truck (LM7, LR4, LQ4, LQ9, L33)	0.537	0.551	1.865	Mini Delphi (Multec 2)
LS2	0.533	0.551	2.0	USCAR
LMG (E85)	0.533	0.551	2.0	USCAR
L59 (E85)	0.533	0.551	2.08	USCAR
LS1, LS6	0.537	0.551	2.65	Jetronic / Minitimer	LS1/LS6 67 mm conflicts with article text "38mm to 64.8mm"

Sources