Airflow -> Dynamic - Initial VE correction Factor table

Table 13426

The Initial VE airmass correction factor table is indexed to Baro and ECT.

I see little about this table in my searches. After constantly messing with Idle airflow (the Startup Airflow and MAF SS airflow tables under the Idle tab), I consistently read high in startup airflow values and actual measured airflow, even with VVE pretty well dialed in when hot.

Anyone have experience with how this table works, aside from a straight adjustment relative to Baro and ECT? I suspect it may be why my airflow values are really high on startup, which might explain why my startup is idling high and then timing is pulled to reduce engine RPM at idle?

In stock form, it looks like it should be multiplying VE values by 1.15 to 1.2 in colder temps, ie an adjustment to the "hot" VVE values?

Quote:

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Originally Posted by Random84

Table 13426

The Initial VE airmass correction factor table is indexed to Baro and ECT.

I see little about this table in my searches. After constantly messing with Idle airflow (the Startup Airflow and MAF SS airflow tables under the Idle tab), I consistently read high in startup airflow values and actual measured airflow, even with VVE pretty well dialed in when hot.

Anyone have experience with how this table works, aside from a straight adjustment relative to Baro and ECT? I suspect it may be why my airflow values are really high on startup, which might explain why my startup is idling high and then timing is pulled to reduce engine RPM at idle?

In stock form, it looks like it should be multiplying VE values by 1.15 to 1.2 in colder temps, ie an adjustment to the "hot" VVE values?

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Quoting myself - ok. a 5pct reduction in this table drastically reduced cold start airflow, so however the math is computed, it is much more exponential than linear.

It is used in the Dynamic airflow calculation. A little more information from HPT is here: https://www.hptuners.com/help/vcm_ed...ow_dynamic.htm

I do not see many adjusting this table. High airflow with timing being pulled to me sounds like idle/startup airflow is to high which does not allow the throttle to close. The computer then tries to use timing to reduce RPM.

Quote:

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Originally Posted by eXo3901

It is used in the Dynamic airflow calculation. A little more information from HPT is here: https://www.hptuners.com/help/vcm_ed...ow_dynamic.htm

I do not see many adjusting this table. High airflow with timing being pulled to me sounds like idle/startup airflow is to high which does not allow the throttle to close. The computer then tries to use timing to reduce RPM.

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Of course.

The issue I'm chasing is, when airflow and VVE are more or less dialed in under operating conditions, trying to get cold starts improved seems to be highly limited by the idle vs ECT, MAF SS and Startup airflow tables.

If I lower the idle vs ECT tables, it creates other problems like an RPM dip after coast down.

In for part out!

Long Live OBM's!!

Startup RPM vs. ECT tables and the RPM vs. ECT table have reasonable values entered and the RPM slope as ECT rises reasonably matches across all three tables?
Have you tried lowering startup airflow in the cold problem areas?
Lower MAF S/S? I presume these values should remain slightly higher than the idle area of the main MAF table.
Is there a vacuum leak that closes up when things warm up and expand?
Have you tried adjusting startup rpm flare control?

Can you post a log that details this specific issue, the corresponding tune file, and relevant details of the build?

That's not the table to be adjusting to fix start issues.