You need a new tune it is very unlikely that the SCT and Lightening MAFs would have the same transfer curves.
In the tune the MAF transfer function maps the MAF out signal to an airflow (in lbm/h). The PCM then uses that lbm/h as the basis for injector pulse width and ignition timing.
Just curious. why are you changing from the 90 mm Lightening unit--it is good up to 500+ HP? Unless it's output was pegged at high engines speeds and WOT then neither the SCT BA-2600 or BA-3000 will make any noticeable difference...
- 2003 GT, UPR X, FRPP 24lb/h, Magnaflow, PP 70mm TB & plenum, Delta Force tuned,
Steeda UDPs, Ralco flywheel, RAM HDX clutch, 3.73s, 262 rwHP/305 lb-ft.
New ride (7/1/2013) 1998 Mercedes SL500-5.0L 32V VVT 326/347 HP/tq