STIT and LTIT

[6speedterror]

i was going through the startup and it has this info below

Idle airflow: Log the STIT and LTIT and add the 2 together. With a manual you will use LTIT in gear all the time, autos will use the respective LTIT depedning on the gear selector position. Add the 2 values together (or make a custom histogram) and make chagnes based on ECT. Say 30*C STIT is -0.30 g/sec and LTIT is 0.10 g/sec, you want to subract 0.20 g/sec from the 30*C cell in the idle airflow table. It is important to make these changes only from a cold start as they will give the most accurate data. Make sure it is logging and you make corrections in metric as it adds better resolution. For starters, adding 2 g/sec to the table before initial start up after a cam can help idle.


so i go and log the idle for a bit and for STIT at 30* i have -1.43 and for LTIT i have -3.00 g/sec, do i all the whole numbers as well or only what is after the decimal.

[redhardsupra]

i've seen LTIT on many cars stuck on some seemingly arbitrary number, so i just ignore it and go purely off STIT. works great for me, my own car is tuned to within 0.05g on STIT across the full range of temps

[6speedterror]

so as long as the as STIT are close to 0 ill be fine?

[12secSS]

i've seen LTIT on many cars stuck on some seemingly arbitrary number, so i just ignore it and go purely off STIT. works great for me, my own car is tuned to within 0.05g on STIT across the full range of temps

That is exactly what I do as well. So long as you are +/-0.05g/sec, the idle airflow will be fine.

[Russ K]

When a 160* stat is installed, I set the adaptive idle min ECT to ~125*. If left at the stock min temp value, the ECT might not get hot enough to enable the adaptive idle (LTIT). Then the LTIT will not change.

I log the desired airflow in g/sec and plot it against ECT in the histogram. Then I copy the histogram into the base running airflow table of the editor.

Russ Kemp

[redhardsupra]

russ, where does desired airflow come from? i'm working on a new spreadsheet that arrives at a similar thing but it's based off VE table (i can tune idle precisely this way for cars with no STIT, like LS2)

[Russ K]

russ, where does desired airflow come from? i'm working on a new spreadsheet that arrives at a similar thing but it's based off VE table (i can tune idle precisely this way for cars with no STIT, like LS2)

It is in the pid list under Engine Idle. But I don't think the LS2's have it...yet.

Russ Kemp

[redhardsupra]

i know where it is, i meant where does it come from, how does it get calculated/sensed?

[stone]

i know where it is, i meant where does it come from, how does it get calculated/sensed?

That's a good question...I would also like to know?

[EC_Tune]

Desired airflow comes from RAF + STIT + LTIT + Throttle Cracker + Throttle Follower