How is a speed-density tune set up on an LS?
Here is what the documentation says. Each point links to its source; tables and names vary by computer, operating system and tuning software.
- E38; LS Gen III/IV; 1997-2013: Speed density tuning models airflow from a three-dimensional volumetric efficiency table indexed by manifold absolute pressure and RPM rather than measuring it directly. (High Performance Academy)
- E38, E67; LS Gen IV; 2005-2013: LS ECMs run a hybrid fueling mode that can be strictly mass airflow, a blend of MAF and speed density, or purely speed density, depending on operating conditions. (LSX Magazine)
- LS Gen III/IV; 1997-2013: A speed density tune is configured so the vehicle fuels from the VE/VVE tables instead of the MAF; on HP Tuners a 0 or 1 in the MAF frequency fail-high diagnostic indicates the car is set up this way. (PCM of NC)
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
- 199 | Optimising Your Tune Using Short & Long Term Fuel Trims (STFT + LTFT) — High Performance Academy
- Late-Model Tuning 101 With EFILive — LSX Magazine
- Remote (Email) Tuning with HP Tuners FAQ — PCM of NC