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Does a turbo LS2 need a 2-bar MAP sensor and OS to tune properly in boost?

Here is what the documentation says. Each point links to its source; tables and names vary by computer, operating system and tuning software.

  • P01, P59; LM7, LQ4, LQ9, LS1, LS2; 1999-2007: HP Tuners' 2-bar/3-bar MAP support (the 2.5-bar custom OS) adds a Boost VE table spanning 105 kPa to 255 kPa with better than 5 kPa resolution in the boost region, retains stock VE resolution in non-boost areas, adds a MAP-referenced Boost Enrich table in 5 kPa steps, and runs in speed-density mode only. (HP Tuners)
  • Sources differ: Conflicts with simpler '2-bar good to 14.7 psi' statements; the OS boost tables actually read to 255 kPa when paired with a 3-bar sensor.
  • E38, E67; LS2, LS3, LS7; 2006-2015: For boosted Gen IV swaps the controller must be set up for a 2- or 3-bar MAP sensor, since the factory calibration only models naturally-aspirated manifold pressure. (LSX Magazine)
  • E38, E67, E92; LS Gen IV; 2005-2013: E38, E67, and E92 ECMs can interpret 2- or 3-bar MAP sensor readings, but the MAP calibration data still has to be changed if the ECU was not originally calibrated for a supercharged engine. (LSX Magazine)
  • Terminator X; LM7, LQ4, LQ9, LS1, LS3, LS6; 1999-2013: Terminator X ECUs carry an onboard 1-bar MAP sensor suited to naturally aspirated or nitrous combinations; for boosted applications the internal sensor is disabled and an external sensor is used, with Holley recommending GM part 12592525 plus adapter 558-416 for 2-bar and up. (Texas Speed)

More in fuel, E85 & boost, 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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