Part throttle tuning step by step.

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Sep 15, 2002 | 02:48 PM

PewterZ28

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From: St.Louis, MO

Part throttle tuning step by step.

I have read Chris B's web site and have searched this website. I understand "what" to do but I'm not sure if I know "how" to do everything. Please look over this and let me know if I got it right. The part I'm least sure about is 1 and 2. If I could get some replies to this, maybe it can go into Chris's site?

1. Connect autotap and log Ltrims for by cruising on highway for 20 minutes in overdrive?
2. "Highlight?" all Ltrim data and load into excell? (not sure how to do this)
3. Average Ltrim data and obtain value.
4. Multiply MAF talbe in LS1 Edit by appropriate value to bring Ltrim avg to -1 to -3?
Appropriate value is derived by taking average and subtracting -1 or -3 and adding 100. EX: +5 - (-3) = 108.???
5. Verify Ltrims with autotap by repeating steps 1 to 3.

Thanks for your help.
Derrick

Sep 15, 2002 | 08:51 PM

Ragtop 99

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Re: Part throttle tuning step by step.

you export to a csv file in auto tap. There is a command on one of the menus. Excel reads that format.

After transferring to Excel, I'd use fuel trim cells 1 - 16 only, or eliminate all data with TPS<1%

Otherwise, steps 3,4,5 are fine.

Sep 16, 2002 | 09:42 PM

PewterZ28

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Re: Part throttle tuning step by step.

Cool. Thanks for helping out.
Am I right about cruising on the highway or should I be doing stop and go type driving?
Also, I'm a little confused about looking only at cells 1-16? How do I do that?

Sorry for the dumb questions, gotta figure this stuff out.

Thanks,
Derrick

Sep 17, 2002 | 08:52 PM

PewterZ28

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Re: Part throttle tuning step by step.

ttt

Sep 17, 2002 | 10:13 PM

Ragtop 99

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Re: Part throttle tuning step by step.

You want a mix of city and some highway.

fuel trim cell is a metric that you can select in autotap. You then sort the data in excel on that column (or TPS) and eliminate those rows. Then do your calcs. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Sep 18, 2002 | 06:15 AM

PewterZ28

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Re: Part throttle tuning step by step.

Thanks for the help Ragtop! I think I understand now. I'm using my friends autotap and I'm not familiar with all of its functions. That's why I was confused about the fuel cells and where they were.

One thing I have noticed, however, is that people seem to disagree as to which fuel cells are for part throttle. I've seen 3 or 4 different variations.

For example, one member posted the following numbers:

Cells 0-5, 21 (no load)
Cells 17-20 (idle)
Cells 6-14 (part throttle)
Cells 22 & 15 (WOT)

According to these numbers, I should look at cells 6 to 14??? (I notice he does not account for cell 16, why not?)

Another member says, "I average the numbers for fuel cells 1-19."

Yet another search I did says to ignore fuel cells and go by MAF frequency, whatever that means? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

The more I read the more I go --> <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> <img border="0" alt="[barf]" title="" src="graemlins/gr_barf.gif" />

Who is right?

<small>[ September 18, 2002, 06:45 AM: Message edited by: PewterZ28 ]</small>