Quick question about LTIT STIT on m6

[walterdy]

I was trying to verify on a 04 gto, ls1 stock h/c, m6, in speed density mode.

In trying to fine tune the idle I have been logging LTIT and STIT during cold at idle. I have included the log file but basically it shows -.24 LTIT and 0 on STIT for the most part but sometimes it jumps to .25/.26.

Am I correct in adjusting the base running airflow, idle airflow vs coolant temp table at the appropriate ECT to add -.24 to those cells?

Thanks for the help!!!!

[WS6FirebirdTA00]

I would only recommend making changes based on a cold startup log.

[walterdy]

Is it true on manual cars you always ignore the stit value?

[WS6FirebirdTA00]

No.

[Billf6531]

I played back your log using the RAF histogram, and derived the following values for your RAF table, starting at 111*F.

10.58363 10.05565 10.48226 9.08207

You may wish to give them a try and then log again from a cold start. Don't drive the car, just log and don't touch the throttle.

[walterdy]

Sweet!! I will give it a shot thanks! Man, wish I could get up to Edmonton and see some of my relatives. Went up there a few years ago, still very nice up there!

[walterdy]

With the LTIT STIT raf adjustment, I have enclosed a log from after the changes you suggested, would you be willing to see if it is on target now? If certainly seems better. I tried the idle airflow histogram but I wasn't sure if I should multiple by * or what?

Thanks again,
Walter

[WS6FirebirdTA00]

It is still off, and IMO you have way too many PID's. If you are logging for idle just put in the stuff you need for that. You will get a much faster sample rate. Also, I recommend only making idle air changes from a cold start up to operating temperature.

[Billf6531]

Wow, big change. If you have an Idle Histogram, it should fill the temperature cells with these values starting at 20*C or 68*F:

14.67632, 13.04449, 8.35162, 7.14436, 6.80210, 6.52780

I used [SENS.20]=0 in the histogram to filter out your driving after it warmed up, but it made no difference in the end result. The key part was starting from a cold engine, cold morning, and not touching the throttle.

If you agree, paste those values into your idle table, and do one more cold scan tomorrow to verify.

If you click on the C in your histogram, you'll see that you had between 100 and 600 samples for each temperature cell. IMHO, that's plenty. BTW, where are you? The reason I ask is so that I can use the correct temperature scale, and not confuse things.

[WS6FirebirdTA00]

oops! I was looking at IAT and not ECT.

starting at 20*C add these values to your idle airflow table

20*c 0.89476
32*c 1.16693
44*c -2.20938
56*c -3.02688
68*c -3.41896
80*c -3.02074

[walterdy]

Guys, I really appreciate the help, I made the suggestions provided by WS6 and damn I think it is really really close. Thanks again!!!! Here is the cold start log from this morning just in case you want to check it out for yourself.

[EC_Tune]

I would throw Vehicle speed in there so you can log Throttle Cracker & Throttle Follower.

For strictly idle tuning though you are fine. The other values will just help you visualize where you are on the table with a customized histogram.

I'm posting one in the stickies for "airflow" tuning.

[walterdy]

Cool, I will d/l the airflow one and give it a try. I just upgraded to 1bar enhanced SD today so I am looking forward to checking it out as well.

[WS6FirebirdTA00]

Much better, makes it easy to read with less parameters too. I normally only log what I am going to look at for making changes. Now time to learn.

Ever made a custom histogram? If not now is a good time to learn. You can make a custom PID to add STIT and LTIT together, and log it vs your idle airflow table ECT range. This way you will keep a running average of it. Do it from a cold start, and do not drive the car or give it gas. That is what I did to get you your values before, just filtered out ECT above a certain point.

Give it a shot. You can scan through the PID list to find STIT and LTIT in gear. Open the scanner without a log open, right click on the table, hit insert and go to configure user defined. This is the equation you will use for idle airflow:

[PID.2240]+[PID.2229]

After you set that up, close the box and open this file. Go into the area where you can edit the histograms. You will want to use this PID for plotting and under x header> table, select idle startup frictional airflow. This will make the x axis the same as the x axis as your idle airflow table. Now if you did it right you should beable to load all data and it will show this:

Here is what I get with my table:

20*c 1.76
32*c 0.02
44*c -1.18
56*c -0.21
68*c -0.25
80*c -0.09