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nyet
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« Reply #30 on: January 14, 2019, 01:47:54 PM »
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At WOT actual load may never track requested. As long as it is under requested you won't get torque intervention (which is what you want anyway)
It is more important that actual boost tracks requested.
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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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Garfimp
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« Reply #31 on: January 14, 2019, 02:00:26 PM »
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At WOT actual load may never track requested. As long as it is under requested you won't get torque intervention (which is what you want anyway)
It is more important that actual boost tracks requested.
Yes thanks  I will work on my overboost around 3500 rpm to make it less high. However that still doesn't help me find out why my requested boost is lowering from 5500/6000 rpm and on.. Making actual load way lower than requested load at high rpm  Said differently, why at 4000 rpm when my requested load is 180, my requested boost is around 2200, and at 6000 rpm when requested load is 180, requested boost is around 2100 or even less? |
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« Last Edit: January 14, 2019, 02:31:01 PM by Garfimp »
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nyet
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« Reply #32 on: January 14, 2019, 05:21:31 PM »
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Said differently, why at 4000 rpm when my requested load is 180, my requested boost is around 2200, and at 6000 rpm when requested load is 180, requested boost is around 2100 or even less?
Because load and boost are not even remotely linearly related, as outlined in the S4wiki tuning article. |
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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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Garfimp
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« Reply #33 on: January 14, 2019, 11:32:34 PM »
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Because load and boost are not even remotely linearly related, as outlined in the S4wiki tuning article.
Yes I know and I've read the wiki maaaaany times  , but the rlsol to plsol calculation part is difficult for me and I still didn't find what is limiting my req boost. So we have (source = your excellent wiki ) : plsol = (rlsol + rfagr) / fupsrl / fpbrkds / vpsspls Where :
rfagr is the amount of airmass displaced by the residual pressure leftover from the last cycle
fupsrl is the 100% load -> 1 bar conversion (dependent on tans)
fpbrkds is the pumping correction based on VE
vpsspls is the pressure drop across the throttle plateBut I admit I don't really know what to make of it..or in what maps I can make those parameters different.. Also I read about IAT and KFTARX maps that are involved in the plsol generation, I can try to alter these maps, but it is winter here and I don't think they are limiting anything... Also in Wiki the more simple relation between pssol and plsol:
plsol = pssol/vpsspls
vpsspls = ~1.016 (from KFVPDKSD/KFVPDKSDSE)
So maybe I should look into "KFVPDKSD/KFVPDKSDSE"? Or am I totally mistaken? lol Anyway I will keep looking also in the FR but thought someone might help on that  |
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« Last Edit: January 15, 2019, 03:09:55 AM by Garfimp »
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nyet
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« Reply #34 on: January 15, 2019, 08:03:01 AM »
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Short answer: increase LDRXN and/or KFLHBN.
You were expecting a linear relationship between load and boost. There isn't one, and you do not want to change that.
If you want more boost, request more load, unless boost is being limited by HBN (also outlined in the wiki).
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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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Garfimp
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« Reply #35 on: January 15, 2019, 08:09:43 AM »
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Short answer: increase LDRXN and/or KFLHBN.
You were expecting a linear relationship between load and boost. There isn't one, and you do not want to change that.
If you want more boost, request more load, unless boost is being limited by HBN (also outlined in the wiki).
Ok thanks Nyet But that means that at high rpm you can't have actual load matching your requested load? At 6000 rpm I request 180 load, but the requested boost is not enough to have an actual load of 180... Do you understand my point? Meaning the proper way to tune is having 200 requested load, for instance, at 6000 rpm in order to have an actual of 180 ?  |
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nyet
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« Reply #36 on: January 15, 2019, 08:21:40 AM »
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Yes.
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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 #37 on: January 17, 2019, 09:12:37 AM »
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Yes.
No, the proper way is to reconfigure the VE map so that it requests the correct amount of pressure for a given load. But as a hack the above will do. |
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nyet
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« Reply #38 on: January 17, 2019, 10:04:40 AM »
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No, the proper way is to reconfigure the VE map so that it requests the correct amount of pressure for a given load.
But as a hack the above will do.
I can't tell if any mods he has done would require changing the VE map. If the VE map is wrong due to modifications, then yes, he should fix it. If it isn't wrong, and the load disparity is close enough, I don't see a reason to retune the VE maps. If the disparity is large enough, AND there is no physical mod that would justify changing the VE map, then fixing the VE map is also the wrong solution; it means there is something mechanically wrong. |
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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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Kacza
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« Reply #39 on: January 17, 2019, 01:06:31 PM »
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What is this VE map?
Not everyone understands yours slang.
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nyet
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« Reply #40 on: January 17, 2019, 01:17:25 PM »
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What is this VE map?
Not everyone understands yours slang.
If you don't know what Volumetric Efficiency is, I would suggest probably not doing any tuning w/o doing a bit more learning first. Roughly, it is the relationship (pump efficiency) between displacement (how much air a pump can hold) and how much of that air actually makes it out the exhaust. It is the largest variable (other than IAT) influencing the pressure/load/flow relationship. Also, there is no single VE map in modern ECUs. I am using it shorthand to describe VE's influence on the load->boost and boost->load relationship. |
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« Last Edit: January 17, 2019, 01:19:50 PM by nyet »
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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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Garfimp
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« Reply #41 on: January 17, 2019, 01:32:08 PM »
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No, the proper way is to reconfigure the VE map so that it requests the correct amount of pressure for a given load.
But as a hack the above will do.
Very interesting, thanks If you don't know what Volumetric Efficiency is, I would suggest probably not doing any tuning w/o doing a bit more learning first.
Roughly, it is the relationship (pump efficiency) between displacement (how much air a pump can hold) and how much of that air actually makes it out the exhaust.
It is the largest variable (other than IAT) influencing the pressure/load/flow relationship.
Also, there is no single VE map in modern ECUs. I am using it shorthand to describe VE's influence on the load->boost and boost->load relationship.
Thank you Nyet for the explanation, I will dig into that. The question is : should I bother trying to reconfigure the VE or simply up my LDRXN values in high rpm ? Haha |
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nyet
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« Reply #42 on: January 17, 2019, 01:37:00 PM »
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The question is : should I bother trying to reconfigure the VE or simply up my LDRXN values in high rpm ? Haha Is there reason to believe any hardware changes you made would affect VE? If not, don't recalibrate the VE. If you still see large actual/req load divergence when there is no actual/req boost divergence, something is wrong mechanically, IMO. |
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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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Garfimp
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« Reply #43 on: January 17, 2019, 01:44:12 PM »
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Is there reason to believe any hardware changes you made would affect VE? If not, don't recalibrate the VE.
If you still see large actual/req load divergence when there is no actual/req boost divergence, something is wrong mechanically, IMO.
No hardware changes, car is stock for now so I will simply up LDRXN I guess |
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Kacza
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« Reply #44 on: January 19, 2019, 03:28:55 AM »
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If you don't know what Volumetric Efficiency is, I would suggest probably not doing any tuning w/o doing a bit more learning first.
Roughly, it is the relationship (pump efficiency) between displacement (how much air a pump can hold) and how much of that air actually makes it out the exhaust.
It is the largest variable (other than IAT) influencing the pressure/load/flow relationship.
Also, there is no single VE map in modern ECUs. I am using it shorthand to describe VE's influence on the load->boost and boost->load relationship.
I do not know the concept of VE, and yet my cars are driving long and very well. I see that this is a very important concept because there is one topic on the forum about it. http://nefariousmotorsports.com/forum/index.php?action=search2In my environment, there is the concept of EMP. |
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