Forcing LGX to Speed Density mode - stock dynamic airflow settings don't make sense?

[CYN_CRVR]

The attached screenshot is of the stock tune from my 2023 3.6 Camaro V6. It has not been edited.

I thought most ECMs have a dynamic airflow high RPM limit around 4k rpm, and you crank that value up (among other steps) to bypass the MAF and force speed density mode. But my stock settings appear to already be set to redline, which doesn't make sense to me.

Any ideas about what's going on here?

It's worth noting that HPTuners just added support for my vehicle this past month, and I found that one table was initially being read incorrectly (although it's already been fixed thanks to speedy ticket handling by the support team). Could this be another case of incorrect ECM reading?

[KillboyPowerhead]

Not sure if the tables would be the same as the LFX, but my tables are [ECM] 3003 for High RPM Disable (value 4000) and [ECM] 3033 for High RPM Re-enable (value 3900).

FYI, not sure if you're wanting to force speed density for the purposes of tuning the VVE, but if so you can leave the MAF active and tune both at the same time with no issues.

[Shane Hewitt]

Those values are consistent with the 2019 I just tuned recently.

[CYN_CRVR]

Not sure if the tables would be the same as the LFX, but my tables are [ECM] 3003 for High RPM Disable (value 4000) and [ECM] 3033 for High RPM Re-enable (value 3900).

FYI, not sure if you're wanting to force speed density for the purposes of tuning the VVE, but if so you can leave the MAF active and tune both at the same time with no issues.

Yes that was the plan, although I have also been reading up on tuning both at the same time. Thanks for the input!

[CYN_CRVR]

Those values are consistent with the 2019 I just tuned recently.

Thanks - nice to know. If you don't mind sharing:
- Did you tune VVE and MAF separately or at the same time?
- If separate, how did you force VVE-only and MAF-only?
- If same time, did you use the method outlined by smokeshow or Cringer?

[KillboyPowerhead]

When I first started tuning my LFX I failed the MAF to tune SD first, but ended up realizing it was just a waste of time and tuned both at the same time. I still have some notes, however. I think the following is everything you need to do to allow you to run with a failed MAF sensor (I'm assuming the LFX and LGX are very similar).

a. Engine > Airflow > Dynamic
Dynamic Airflow - High RPM Disable from 4000 to 8000
Dynamic Airflow - High RPM Re-enable from 3900 to 7900
This will prevent the MAF sensor from being involved in airmass calculations (even when failed it still reads/sends data).

b. Engine Diag > Airflow
Mass Airflow Sensor - MAF Frequency Fail High from 14500 to 0
Mass Airflow Sensor - MAF Frequency Fail Low from 800 to 16000
This will fail the MAF sensor when the sensor reads between 0 and 16000 Hz (i.e. always failed).

c. Engine Diag > Airflow
Airflow Correlation > P0068 Enable RPM from 800 to 8000
P0101, P0106, P0121 > Min ECT from 19 to 492; Max ECT from 302 to -40
This will prevent the ECU from going into Reduce Engine Power mode due to a failed MAF.

d. Engine Diag > DTCs
Set P0101, P0102, P0103 from MIL on Second Error to Mil on First Error; uncheck SES Enable
This will set MAF sensor-related DTCs upon first failure (i.e. right away) and also keep MIL off for these codes (so it can still illuminate if other codes exist).

I believe to run MAF only you can keep everything stock, and then referring to step a, set the values real low (like 1 and 0) so that the MAF is always being used. Don't believe there was anything else required but I could be wrong.

As for actually tuning, I recently posted something real quick which summarized what I did. https://forum.hptuners.com/showthrea...-starting-over

[Shane Hewitt]

Thanks - nice to know. If you don't mind sharing:
- Did you tune VVE and MAF separately or at the same time?
- If separate, how did you force VVE-only and MAF-only?
- If same time, did you use the method outlined by smokeshow or Cringer?

If your car is stock I think you'll likely find that GM's airflow models are pretty good. On the car I was dealing with I don't think spending the time to tune VVE would have made any improvements at all. This particular car had an aftermarket intake that skewed the MAF curve pretty significantly, so I did have to spend the time to dial that in. In my case, I set the Dynamic Airflow Enable/Disable values to something low (I wanna say I had them well below 1000 rpm from memory), used the scanner to force open loop and clear fuel trims and went for a drive with my wideband installed. Copy AFR error % to your MAF curve and re-evaluate. Took 2 WOT pulls to dial it in. Afterwards I re-enabled Dynamic Airflow to the original values. LTFT are all now very close.

.Screenshot 2023-08-27 064655.png