Haltech E6X Manual Win Version - Manual (Page 65)

E6X Manual
65
6.5.7 Fine Tuning the Engine
When fine-tuning the engine for the road, the same principles apply to all engines. Under full
load at all rpm the fuel mixture should be rich. Naturally aspirated engines use an air to fuel
ratio of around 12.5:1 to 13.5:1 is usually best (high performance turbo vehicles may go as
low as 10.5). When cruising (light to medium load) the mixture should be as close to
stoichiometric (14.7:1 AFR) as possible and decelerating conditions may allow the engine to
be run lean to save fuel. This will result in a particular shape for the map.
Note: All maps for all engines should be smooth. A map with a "lumpy" curve
is most likely wrong. If, when you have finished tuning, the map does have
lumps in it; try to make it visually smooth.