IDEAL (Rich) (Lean) Base (ltrims) - 0 + (Lean) (Rich) WOT (O2's) .800 .880-.890 .900 (rich) (lean) A/F (WOT) 12.5 12.8 or .9 13.3 A/F (non-WOT) PCM will try to maintain 14.7:1
Other important numbers...
IAC (idle) : 30-50 IAC (load) : <120 Injector Duty Cycle : See the chart below Knock Retard : 0 Ltrims : 0 (or slightly negative) MAF Flow : ?(30 @ WOT)? Timing : 26-28 WOT, 15-18 idle WOT 02 : .880-.890
Injector duty cycle chart...
The general rule is to not make your injectors work over 80%.
(CHART SAVED FROM http://www.ecanfix.com/~mdhamilton/dutycycle1.html)
|3000||4 ms||8 ms||12 ms||16 ms||20 ms||24 ms||28 ms||32 ms||36 ms||40 ms|
|3500||3 ms||7 ms||10 ms||14 ms||17 ms||21 ms||24 ms||27 ms||31 ms||34 ms|
|4000||3 ms||6 ms||9 ms||12 ms||15 ms||18 ms||21 ms||24 ms||27 ms||30 ms|
|4500||3 ms||5 ms||8 ms||11 ms||13 ms||16 ms||19 ms||21 ms||24 ms||27 ms|
|5000||2 ms||5 ms||7 ms||10 ms||12 ms||14 ms||17 ms||19 ms||22 ms||24 ms|
|5500||2 ms||4 ms||7 ms||9 ms||11 ms||13 ms||15 ms||17 ms||20 ms||22 ms|
|6000||2 ms||4 ms||6 ms||8 ms||10 ms||12 ms||14 ms||16 ms||18 ms||20 ms|
|6500||2 ms||4 ms||6 ms||7 ms||9 ms||11 ms||13 ms||15 ms||17 ms||18 ms|
|7000||2 ms||3 ms||5 ms||7 ms||9 ms||10 ms||12 ms||14 ms||15 ms||17 ms|
|7500||2 ms||3 ms||5 ms||6 ms||8 ms||10 ms||11 ms||13 ms||14 ms||16 ms|
|8000||2 ms||3 ms||5 ms||6 ms||8 ms||9 ms||11 ms||12 ms||14 ms||15 ms|
Basic A/F tuning...
You must tune your base setting (ltrims) first! Once your base is set - you can tune WOT. The o2 sensors in our cars are not all that great (only used for emissions - not operations), so many recommend tuning WOT on a wideband dyno, others say that's not necessary. Tuning by the stock o2's will at least get you close... so start with that. If you have some extra $$$... get a dyno (you do want to get your new HP and TQ numbers anyway) and see how close your o2's were.
Changes to your ltrims do not take effect immediatly - you must drive (at least 50 minutes) to allow time for the PCM to relearn it's fuel curve, then do some more atap logging and see how your're running.
tuning ltrims by modifing the IFR
multipling the table by >100% will make you leaner.
multipling the table by <100% will make you richer.
this is the way it was explained to me - makes sense if you think about
you are multipling the injector flow rate.
the larger the value is - the larger the pcm thinks the injector is (able to spray more fuel), so the pcm shortens the injector pulse width time (length of time the injector sprays fuel), thus making you leaner. the opposite is also true.... smaller numbers makes the pcm think small injector flow, so it lengthens the pulse width, thus making you richer.
tuning o2's by modifing the PE vs. RPM
multipling the table by >100% will make you richer.
multipling the table by <100% will make you leaner.