How do you transfer injector data correctly when swapping to larger injectors at a different fuel pressure?
Here is what the documentation says. Each point links to its source; tables and names vary by computer, operating system and tuning software.
- The fuel-pressure reference type (atmospheric vs manifold-referenced) must be set correctly because injector flow and dead time vary with differential fuel pressure. (High Performance Academy)
- LS Gen III/IV; 1997-2013: An injector's effective flow rate changes with both fuel-rail pressure and intake vacuum, which is why return-style systems reference the fuel pressure regulator to intake manifold vacuum. (LSX Magazine)
- E38, E67, P01, P59, Terminator X; LM7, LQ4, LQ9, LS1, LS3, LS6; 1999-2013: When sizing injectors, confirm the selected flow rate at the fuel pressure the system will actually run, and account for a boost-referenced regulator raising base pressure proportionally with boost. (LSX Magazine)
More in tuning fundamentals, or build a checklist for your swap with the tune checklist tool.
Confidence: medium — sources disagree or are limited; check the sources below.
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Sources
- Fuel For Thought: Sizing Port Fuel Injectors for High-Performance Engines — LSX Magazine
- Late-Model Tuning 101 With EFILive — LSX Magazine
- 118 | Understanding Injector Characterisation - AEM Infinity — High Performance Academy