The main fuel mapping, or Volumetric Efficiency table, is fairly intimidating at first glance. The tables are organized by MAP reading and range from 20 to 100 MAP. Theoretically, any change in an engine's volumetric efficiency will require work on these tables. However, the tables probably won't need work if your changes are within the correction limits (most bolt-on parts) of the feedback control from a good working factory O2 setup. Mods such as big cams or increased displacement are going to require VE table tuning.