How do I tune an LS swap? (HP Tuners basics)

The basics of tuning an LS swap with HP Tuners are simpler than they look: leave 99% of the tables alone and focus on VE, MAF and idle airflow. Because GM computers are self-contained, many swaps only need VATS disabled, the speedo recalibrated and the MAF transfer fixed if the air inlet isn't stock. We recommend running OE injectors and copying the injector tables from the vehicle they came from, since aftermarket injectors are mostly junk. From there, take datalogs, build histograms and use cut-and-paste map transforms to correct the tables.

Check this first:

• Save a copy of the stock tune before changing anything
• Disable VATS
• Confirm which vehicle your injectors came from so the injector data matches
• Take a datalog before and after each change

Careful: Bad fueling tables can lean the engine out, so check your logs before putting load on it.

Based on what we've seen work across our own builds, our friends' builds and the wider LS community, reviewed by our lead shop tuner (over 20 years of LS and LT tuning experience). Every combination is different, so use at your own risk and check our safe tuning limits before any wide-open pass.