Mythbuster74
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« on: August 08, 2014, 02:40:59 PM »
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So I bought a bigger aluminum maf housing and am using the original maf sensor. I cannot for the life of me get my fuel trims and idle to be correct. I believe I have a halfway decent KRKTE of 3-3.2 depending on what maf settings im using, and the correct tvub values. Can someone help me out here pleaseeeeeeeeee
870cc injectors at 3 bar, have a 4 bar regulator
Orginal maf housing size= stock 60mm
New maf housing size= 95mm
Attachments
The first file is an original tune for an ATW engine code car (aka the maf sensor I have)
Second is my current tune.
And third is my maf transfer function file, derived from the stock atw file.
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Mythbuster74
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« Reply #1 on: August 08, 2014, 03:02:49 PM »
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Here are the map packs for both files that I've been using.
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Mythbuster74
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« Reply #2 on: August 08, 2014, 03:06:24 PM »
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Forgot to add this, but I have switched from the stock narrowband me7.5 (018P) to a wideband me7.5 (018CH).
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Mythbuster74
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« Reply #3 on: August 09, 2014, 06:09:50 AM »
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I'm thinking that maybe they have different maf offset values, so I'm currently searching for those maps. Maybe I have a bad maf sensor?
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Mythbuster74
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« Reply #4 on: August 10, 2014, 05:25:13 PM »
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Replaced maf sensor with the correct awm version. Used the scaling program. Still getting lean idle, negative fuel trims under cruise, positive under load. Also have a kfmirl that is equal to the boost pressure i'm currently running at fuel throttle.
Nobody has ideas?
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TopNotch
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« Reply #5 on: August 11, 2014, 11:15:13 PM »
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mmm personally I would get the injectors dialed in first then do the maf? Or maybe you did this already? I have to tackle the same issue soon enough with 830cc and vr6 maf. Did you look at FKKVS or KFKHFM possibly this is what I was told should be dealt with also with bigger injectors and maf
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Mythbuster74
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« Reply #6 on: August 12, 2014, 06:04:04 AM »
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mmm personally I would get the injectors dialed in first then do the maf? Or maybe you did this already? I have to tackle the same issue soon enough with 830cc and vr6 maf. Did you look at FKKVS or KFKHFM possibly this is what I was told should be dealt with also with bigger injectors and maf
Yes i'm aware of those maps but I'm unsure which one is the correct fix. I'm leaning more towards kfkhfm because my intake setup is a bit funky. Now I'm trying to figure out what to actually log to fine tune my maf readings. Anyone have input here? I'm thinking of logging msdk_w (mass air flow over throttle plate), which I believe is a calculated value in the computer, and mshfm_w, the actual measured value. Then making changes according to how far off they are in mlhfm. Is this correct? Or should I leave my mlhfm table normal and make changes in kfkhfm? |
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Mythbuster74
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« Reply #7 on: August 12, 2014, 09:19:59 AM »
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Here's a log of a third gear pull almost to readline, I think I've logged enough variables to have something useful. There's also a graph of what I proposed in the last post.
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Mythbuster74
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« Reply #8 on: August 13, 2014, 09:36:58 AM »
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I'm not sure why I have so many views and only one reply, have I done something to make people mad?
Any advice here would be much appreciated
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phila_dot
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« Reply #9 on: August 13, 2014, 09:55:16 AM »
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IMO it is difficult to talk someone through this process.
My advice is to use a logical process and use the maps/parameters as intended.
FKKVS is to correct error at specific on times. This should be below the knee and before the minimum pulsewidth.
Isolate what you are tuning as best as possible.
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Mythbuster74
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« Reply #10 on: August 13, 2014, 10:02:00 AM »
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IMO it is difficult to talk someone through this process.
My advice is to use a logical process and use the maps/parameters as intended.
FKKVS is to correct error at specific on times. This should be below the knee and before the minimum pulsewidth.
Isolate what you are tuning as best as possible.
The more I read the more I kick myself for not doing this. To set it back to stock my two options are to a. stick the old maf on the new intake tract setup or b. throw the old injectors back in. The problem with option a is obviously the intake tract is far far different from stock. The problem with option b is the stock injectors max out fairly quickly. So should I stick the stock maf on and hope that it's close enough? Or run much less boost and try to dial in the new maf housing? Which is the lesser of two evils? |
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Mythbuster74
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« Reply #11 on: August 13, 2014, 10:23:22 AM »
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Nyet made a post but deleted it I guess? And said to "Compare req to wideband readings". This graph is what he means correct?  |
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nyet
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« Reply #12 on: August 13, 2014, 10:28:16 AM »
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i didn't see that you converted from nb to wideband
in that case, you can simply tune MLHFM by short term trim.
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ME7.1 tuning guideECUx PlotME7Sum checksumTrim heatmap toolPlease do not ask me for tunes. I'm here to help people make their own. Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
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phila_dot
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« Reply #13 on: August 13, 2014, 11:17:59 AM »
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The more I read the more I kick myself for not doing this. To set it back to stock my two options are to a. stick the old maf on the new intake tract setup or b. throw the old injectors back in.
The problem with option a is obviously the intake tract is far far different from stock. The problem with option b is the stock injectors max out fairly quickly.
So should I stick the stock maf on and hope that it's close enough?
Or run much less boost and try to dial in the new maf housing?
Which is the lesser of two evils?
I would do stock injectors and tune MAF for idle and part throttle, then swap in your injectors and tune them at idle/part throttle. Finally, finish tuning the MAF. |
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nyet
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« Reply #14 on: August 13, 2014, 11:19:42 AM »
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I would do stock injectors and tune MAF for idle and part throttle, then swap in your injectors and tune them at idle/part throttle. Finally, finish tuning the MAF.
I agree. Get the MAF dialed in right first. |
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ME7.1 tuning guideECUx PlotME7Sum checksumTrim heatmap toolPlease do not ask me for tunes. I'm here to help people make their own. Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
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