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Old Oct 5, 2007 | 12:18 PM
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From: Coastal Maine
A quick question about Accel Enrichment

Does the ECU only refer to the 2D cell that you are at when you stab the throttle? Or does it use a broad range of RPMs? If so, how long does it look at this table after you floor it? Im trying to tune out an overly rich dip at peak tq/boost. Ive got lean spool disabled. In most of my logs I punch it below 3k, and the rich dip is at around 4k. Do I just modify the 4k cell of the Enrichment table, or is the ECU "done" with the Enrichment table by then? If it "done", I would assume that I need to change the cell that I floored it in. I did some searching on the topic, but couldnt come up with any conclusive answers. All I know is that the number is qty and duration.

thanks
CB
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Old Oct 5, 2007 | 12:20 PM
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I took everything 3000 and beyond and took it down two clicks (ie. hit the " - " button twice)

Seems to have helped a bit, although the rich dip isn't completely gone
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Old Oct 5, 2007 | 12:39 PM
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From: Coastal Maine
Thanks. Your previous post on the subject is one that I was reading. How much did that affect yours?

It seems that it hits 10.7, not matter how I change my fuel map. Ive gotten to the point to where Im very reluctant to keep leaning it out. I am assuming that it has something to do with my K&N cone. But since my fuel trims are within reason, I dont want to change my maf scaling.
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Old Oct 5, 2007 | 12:49 PM
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accel enrichment is very short. It richens the AFR to compensate for the sudden extra air coming in when there is an sudden increase in throttle. If it didn't then the car would go too lean and knock.

It seems to be different in different gears for me, probably because different gears have higher or lower rate of change of load. I forget what my car drops to but I remember 12.5 AFR from long ago.

Anyway, I don't think accel enrichment will fix your problem.

Last edited by roger smith; Oct 5, 2007 at 12:58 PM.
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Old Oct 5, 2007 | 01:20 PM
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From: Coastal Maine
Here is a log of what Im trying to tune out. Not current (I dont have access to my laptop right now), but it gets the point across
Attached Files
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Old Oct 5, 2007 | 01:32 PM
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From: Ventura County, CA
Looks like increase your fuel map at 260 load and 4000 rpm.

Last edited by roger smith; Oct 5, 2007 at 01:36 PM.
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Old Oct 5, 2007 | 01:39 PM
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No matter how much I increase it, I still get 10.7. The log I posted is from a week or so ago. Currently, my AFR is much more steady, with a bit more timing up top. And Ive leaned out that area of map in several steps, up to +1. And it is still 10.7. Everytime Ive modified my map, this area gets attention.
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Old Oct 5, 2007 | 03:23 PM
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I leaned it out a little bit in that area, now Im seeing different AFR readings in the same load/rpm cell. It registers 11.6 11.1 11.6, and the first 2 are in the same cell. Should I just leave it alone?
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Old Oct 5, 2007 | 03:28 PM
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From: Ventura County, CA
Is your fuel map scaled differently?
Have you tried changing multiple cells? like 240/260/280 at once?

The one other thing I'd try is to read your rom and see if the changes are actually there.
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Old Oct 5, 2007 | 04:06 PM
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From: sc
That 10.7 AFR dip at 3900rpm your talking about? Probably notced it's not RPM but load dependant too.

I struggled with that same problem. That's tough get around and all you can do is lessen it. What happens is the WG remains shut as boost and load increase during spool meanwhile ID is ramping to keep up. Once desired boost reached (WG opens) or as the turbo quits incresing boost, the injector duty is still ramping and isn't fast enough to taper back so there is a brief overfuel.

What worked for me somewhat was leaning the load values before peak.
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Old Oct 5, 2007 | 04:37 PM
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The only scaling Ive done is the load. And am starting to think about scaling the RPM differently to have more cells in this area.

Thanks for the info. I'll be trying out some new settings before and at the track tomorrrow.
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Old Oct 14, 2008 | 07:11 PM
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From: Dirty Jerz
how did you resolve this issue?
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Old Oct 15, 2008 | 03:16 PM
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From: Coastal Maine
WOW...almost exactly a year later.

I think I just leaned those areas of the map out a little and it helped, but never completely went away. But there's been so much else thats changed with my tune and some mods since then, Im really not sure.
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