anyone know a good base set of readings
My SCApex's Air Fuel Ratios
12.5-13.5 Idle
13.5-14.5 Cruise
11.8-12.2 Wide Open Throttle
Short version of an article on air fuel ratio:
"In most cases the target air fuel ratio for naturally aspirated engines will be between 12.8:1 and 13.2:1 whereas supercharged, turbocharged, and nitrous injected engines will like a richer mixture between 11.5:1 and 12.5:1"
"Due to the low port velocity and frictional losses Idle mixtures are typically set at a fuel ratio of 12.25:1. Your motor will idle at stoichiometry (14.7:1) or less than stoichiometry but this is very near misfiring and if operating temperatures are not stabilized at a high level the motor will die during abrupt acceleration. Operational fluid temperatures and inlet air temperatures can easily vary 100 degrees Fahrenheit. These variations in temperature
all necessitate different mixture requirements so it is far better to keep the fuel ratio in the 12.25:1 region to preserve idle quality and off-idle responsiveness"
"
There is no magical, absolute, digitized answer to developing your applications fuel requirements. You must drive your machine and a
considerable amount of judgement must be placed in such areas as cold start, warm-up, acceleration fueling, idle quality, and driveability. Each motor is different and the calibration will be only as good as the effort you put into it. Much
subjective decision making will take place and the air fuel ratio meter will not provide you all the answers. Elapsed times, lap times, and
your own opinions as a tester are equally valid"
