L29 7.4/454 Tuning Black Box - SD tuning keeps showing lean

[SiriusC1024]

Rich/lean is O2 switchpoints. Neutral point is 451mV. Set it a little leaner for idle/light throttle. Even for cruise/light accel. Richer for higher loads.

LTFT will be more consistent at a higher temp because the O2's will be more consistent.

[motrhedx81]

So, curiosity is getting the best of me on the O2 switching voltage, and how you determined what voltages to use (change to). I tried to do some research to figure out how you determined what voltage to enter in which cells.

I think I found a connection ... Rich/Lean vs Airflow, which has Airflow Mode on the column axis. Then there is the Airflow -> Mode vs. Airflow, which determines airflow mode based on MAF airflow. Is that right?

motrhedx81 original - left
siriusc1024 - right
rich-lean_airflow_O2_switch_voltage__editor.png rich-lean_airflow_O2_switch_voltage__editor_sirius.png

airflow_mode_vs_MAF_airflow__editor.png

I read a couple of things about logging O2 Voltages against the MAF lb/hr (from the Mode vs Airflow) to try and figure out where the voltage switch point is. The only thing I've been able to get laid out is the AFR to O2 volts (screenshot below). I think this tells me something but it doesn't relate back to the airflow mode. I've looked in the Scanner and I'm not able to log anything against airflow mode.

AFR_to_O2_volts.png

Am I on the right path?

Progress update... I think I'm getting really close on the VE table. Hopefully I just have a couple/few more runs to get in the +/-1.0 LTFT/STFT range across the plot.

[SiriusC1024]

Mode vs Airflow has to do with the PI controller for O2 drive.
https://forum.hptuners.com/showthrea...LTFT-histogram

Switch points are the inflection point. 451mV is the physical actual neutral point of the sensor. When 451 is exceeded P and I start to drive downward. P happens immediately, I happens after integral decays, and they are summed together.

Setting it lower means switching occurs at a lower voltage that equates to leaner AFR. I did this because at idle some fuel is unburned and shows up in the exhaust stream as leaner than it actually is.

Go too far away from the natural neutral/inflection point and PI will become unstable due to the sigmoid response curve of the O2 sensor.

[motrhedx81]

I saw in one of your posts that the Rich/Lean vs Airflow voltage tweak is for tuning. Is it just for tuning and then changed back after I'm finished, or is it a permanent change?