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prj
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« on: August 21, 2012, 01:21:56 PM »
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Does anyone have an explanation for this?
Boost is 1.9 bar right now. Goes lean in mid range due to TE being basically constant, then rich up top. RS4 MAF.
What freaks me out are 1) LOAD, 2) TE
KFKHFM and FKKVS are all 1.
MLHFM copy pasted from RS4.
Some pics:
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prj
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« Reply #1 on: August 21, 2012, 01:23:22 PM »
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The MAF mass-airflow graph looks pretty normal to me, but the load and IPW definitely do not!
Any ideas as to what is going on?
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s5fourdoor
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« Reply #2 on: August 21, 2012, 01:30:59 PM »
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Are you using the actual rs4 airbox flap control? I know Thomas has turned that into a PWM-type thing. I ask this because having compared the MLHFM's, I'm practically guaranteeing you that Audi fudged the upper part of the curvature to account for the increased airflow.
I could dig it up, but I did a log-log plot of the various MLHFM tables, and only the B5 RS4 displayed this excess Kg/Hr curvature profile I'm trying to describe here.
What's your KFLF? Stock RS4?
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« Last Edit: August 21, 2012, 01:34:29 PM by nehalem »
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prj
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« Reply #3 on: August 21, 2012, 01:36:54 PM »
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Are you using the actual rs4 airbox flap control? I know Thomas has turned that into a PWM-type thing. I ask this because having compared the MLHFM's, I'm practically guaranteeing you that Audi fudged the upper part of the curvature to account for the increased airflow.
I could dig it up, but I did a log-log plot of the various MLHFM tables, and only the B5 RS4 displayed this excess Kg/Hr curvature profile I'm trying to describe here.
What's your KFLF? Stock RS4?
This is a 4 banger with ME7.5  I think KFLF does not really come into it, because rl_w is what gets capped out. If you look at the graphs carefully - rl_w and injection time top out at exactly the same spot. I am wondering if pirg_w could play a role... |
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s5fourdoor
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« Reply #4 on: August 21, 2012, 01:40:14 PM »
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OK then, if this is a 4-banger with a converted MLFHM from the RS4 then you almost definitely need to correct the RS4 MLHFM profile. Let me see if I can dig up the spreadsheet I used to do my ad-hoc analysis of this MAF.
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prj
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« Reply #5 on: August 21, 2012, 01:49:02 PM »
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This is what AFR looks like:
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prj
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« Reply #6 on: August 21, 2012, 01:53:15 PM »
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OK then, if this is a 4-banger with a converted MLFHM from the RS4 then you almost definitely need to correct the RS4 MLHFM profile. Let me see if I can dig up the spreadsheet I used to do my ad-hoc analysis of this MAF.
Sorry, I just don't see it being any kind of profile. It is a hard cap on load at 1.3 bar and thus injection time. The RS4 graph looks fairly smooth. This is pressure related if anything (=cylinder charge), not flow related. |
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prj
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« Reply #7 on: August 21, 2012, 02:15:30 PM »
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I am wondering if FPVMXN2 could have something to do with it.
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« Last Edit: August 21, 2012, 02:29:06 PM by prj »
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s5fourdoor
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« Reply #8 on: August 21, 2012, 02:45:16 PM »
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Here's what I was thinking. Scale your MAF as follows and rerun without other changes. I think on second thought that my LambdaPoint=0.0 is correct. Maybe not? ha.
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prj
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« Reply #9 on: August 21, 2012, 02:54:23 PM »
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Here's what I was thinking. Scale your MAF as follows and rerun without other changes. I think on second thought that my LambdaPoint=0.0 is correct. Maybe not? ha.
You are saying to lower the values. I am going to be even more lean then. It is definitely pressure related, every time I hit 220 load, it caps it. I'll try that map I mentioned and see if it helps anything. |
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s5fourdoor
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« Reply #10 on: August 21, 2012, 04:02:59 PM »
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You are saying to lower the values. I am going to be even more lean then.
It is definitely pressure related, every time I hit 220 load, it caps it.
I'll try that map I mentioned and see if it helps anything.
Very interesting. Well, I agree, but if you have 440 g/s it's actually less, say 400 g/s, and yes you'd run lean if you did this holding other things constant. However, you'd adjust this and also adjust KRKTE at the same time to get the WOT you want. The re-centered KRKTE versus your current setup should have lower fueling variance because the metering is more precise. It'll be interesting to see the result of this thread regardless. |
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nyet
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« Reply #11 on: August 21, 2012, 04:30:18 PM »
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Yes. I saw this as well when maxing load with a built motor with larger displacement and stock kumsrl.
The only solution i have is underscale MAF, and bring up KRKTE (if your displacement is stock)
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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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prj
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« Reply #12 on: August 21, 2012, 10:39:41 PM »
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Yes. I saw this as well when maxing load with a built motor with larger displacement and stock kumsrl.
The only solution i have is underscale MAF, and bring up KRKTE (if your displacement is stock)
I don't think KUMSRL is the culprit. It is definitely a MAX cap somewhere. |
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s5fourdoor
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« Reply #13 on: August 21, 2012, 11:15:11 PM »
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kfldhbn? kfmirl?
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nyet
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« Reply #14 on: August 21, 2012, 11:46:32 PM »
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I don't think KUMSRL is the culprit.
For a large displacement motor, it is. For your application i'd just underscale the MAF. |
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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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