Originally Posted by
ralmo94
I personally use the geo that it is on by default, seems to work best for me, at least in open loop.
The way I do it, is dial in the ve first, then I use trimalyzer and filter for pe true and Change the commanded afr the amount it is off from my target afr in arbitrary value mode.
If you Google really hard, you can find a temp versus afr graph, and you can also find an afr vs flame speed graph, and there are more than one with different ranges. Peak heat is around stioch, if I remember correctly peak torque is around 12.8 - 13.5,
And peak horsepower between 11.8 - 12.8. exact place in ranges depend on each individual engine.
If I remember correctly fastest burn speed is at around 12.5-12.8 afr
As you go richer the fuel has a cooling effect to the air as it evaporates. Also more fuel takes longer to burn, these two things are why PE spark is more than the table. Also as you go leaner than stioch it takes longer to burn, why lean burn likes more timing.
Too rich and you are leaving power on the table, too lean and you can induce heat and knock with the heat possibly.
Most Original engines these day can survive full load without pe, example, my dodge NEVER entered PE unless you had it 95% throttle,
And I can assure you it reached full load lots of times at 50-60% throttle.
I like to aim for about 12.8 on the wide band, if there is no knock, I like to go a touch leaner and see if power picks up or drops a noticable ammount along with keeping an eye on kr. If kr occurs either take out timing or add fuel.
That's how I do it.
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