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How to tune low RPM 80-100 kpa?

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Old 05-07-2021, 04:51 PM
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Default How to tune low RPM 80-100 kpa?

How do I figure appropriate VE values for the selected cells? I'm working on my e85 cold start and I am getting it to go out of cranking pretty fast, but as soon as it switches to the VE values in the table here it stalls out a couple times before it will run. I want to make sure I have the VE values reasonable before I play with other things like ASE, ASE taper, etc.



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Old 05-07-2021, 05:55 PM
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You will almost never be in those cells during normal driving, it should only hit those after the car starts and settles to its normal idle. Mine are still at whatever the base VE table had them at.
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Old 05-07-2021, 05:57 PM
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Originally Posted by HowPrayGame
You will almost never be in those cells during normal driving, it should only hit those after the car starts and settles to its normal idle. Mine are still at whatever the base VE table had them at.
I knew this was the only time that the car would see them, but figured that didn't make them unimportant due to the fact that the car is using them during this period of time.
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Old 05-07-2021, 06:05 PM
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If you really wanted to I suppose you could log the starts and check megalogviewer afterwards to see what cells you are hitting and the AFRs you receive at the time, assuming your gauge is giving you good data right after a start
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Old 05-07-2021, 08:24 PM
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What EDIT I do is basically carry over the 2K rpm values horizontally in the ranges you are talking about. ASE
from there. At least that works for me on gasoline.

Let me note that my ASE never goes below 35% adder, however. So, perhaps what you have may be sensible, if you have short ASE Taper. Mine are all at least 13 seconds, so I’m using ASE to stabilize idle for a short period, not just for the flair period.

Seems to work pretty well.

flat VE
I use a LOT of Prime
Followed by hefty ASE
for fairly long periods

Like Ford, when cold, I think rich is better than lean.

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Old 05-07-2021, 09:27 PM
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Idle RPM starts in all gears, vary throttle position, use inclines to extend duration, autotune.
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Old 05-08-2021, 08:05 AM
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Originally Posted by Ted75zcar
Idle RPM starts in all gears, vary throttle position, use inclines to extend duration, autotune.
Good plan. Sure, one can force the use of those cells in a somewhat steady state manner.
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Old 05-08-2021, 12:19 PM
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Thanks for the help everyone. I haven't messed with it yet, but 45 degrees this morning on an 80% blend of e85 and the car started. Took a while but it started. How it starts on 70ish degree days will determine how much I mess with this.
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Old 05-08-2021, 12:27 PM
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I usually find a slight uphill in a quiet area and ride the brakes with my left foot while I throttle up to log those cells. I haven't done it in a long time but that's how I did it. Maybe try 2nd gear.
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Old 05-08-2021, 03:41 PM
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Originally Posted by sonofthehill
I usually find a slight uphill in a quiet area and ride the brakes with my left foot while I throttle up to log those cells. I haven't done it in a long time but that's how I did it. Maybe try 2nd gear.
I just now did it in 5th. Took less Brakes. Maybe I did it in the past? I had less than 2% changes either way from starting points. Tuned down to about 500 RPM. Then copied to my lower RPM cells.
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Old 05-08-2021, 07:08 PM
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Originally Posted by DNMakinson
I just now did it in 5th. Took less Brakes. Maybe I did it in the past? I had less than 2% changes either way from starting points. Tuned down to about 500 RPM. Then copied to my lower RPM cells.
Pretty cool ehh? I did post this method several years ago in tips and tricks, so maybe you tried it then?
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