ottosan
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« on: February 28, 2018, 01:06:46 AM »
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Hello, On my 1.8T after a turbo upgrade engine load is higher than load request although I'm not over boosting. As far as I understand when engine load exceeds load request ignition is retarded. I have read the wiki about fupsrl but I'm not sure if I need to alter KFURL in order to decrease calculated engine load or I just need to request more load.  Another issue I have is the tighter WG I have installed. 0% WG duty cycle is making more boost as boost request at part throttle. S4 wiki states that: Below WG pressure TB needs to regulate boost and that is done by tweaking KFVPDKSD and KFVPDKSE Still trying to understand how to tweak this maps. A WOT log and a screenshot is attached. Any Help is appriciated. Regards, |
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prj
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« Reply #1 on: February 28, 2018, 04:49:31 AM »
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Your VE model (pressure to load conversion) is not right because ECU is requesting too much boost to reach target load.
VE model is adjusted by:
KFURL - base
KFPBRK/KFPBRKNW - multiplicative correction
KFPRG - additive correction
Which one to change I can't tell you based on the data you have - you need to check on part throttle also how it is behaving.
If you have the problem in the entire range, then KFURL will help, if it's only on high boost then KFPBRK/NW should be changed at higher load.
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ottosan
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« Reply #2 on: February 28, 2018, 07:43:53 AM »
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Your VE model (pressure to load conversion) is not right because ECU is requesting too much boost to reach target load.
VE model is adjusted by:
KFURL - base
KFPBRK/KFPBRKNW - multiplicative correction
KFPRG - additive correction
Which one to change I can't tell you based on the data you have - you need to check on part throttle also how it is behaving.
If you have the problem in the entire range, then KFURL will help, if it's only on high boost then KFPBRK/NW should be changed at higher load.
Hello prj, Thank you for your reply. I think that load calculation is false thru all RPM ranges, here is the screenshot of part throttle log in visual logger where from my point of view same as during WOT pull can be observed. I will try to decrease KFURL and log again. Regards, |
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prj
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« Reply #3 on: February 28, 2018, 09:42:23 AM »
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KFURL is pressure to load conversion.
If you decrease it, then the same pressure will result in even less load, and the ECU will request even more boost for the same load.
Also, obviously make sure you don't have boost leaks by pressure testing intake.
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SB_GLI
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« Reply #4 on: February 28, 2018, 11:35:51 AM »
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Also, obviously make sure you don't have boost leaks by pressure testing intake.
Yes. If your MAF readings are higher than they should be (boost leaks, bad MAF readings), your load will also be affected. Did you rescale MLHFM or modify KFKHFM? These could be culprits. |
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nyet
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« Reply #5 on: February 28, 2018, 12:36:24 PM »
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Yes. If your MAF readings are higher than they should be (boost leaks, bad MAF readings), your load will also be affected.
Did you rescale MLHFM or modify KFKHFM? These could be culprits.
I have a habit of slightly numbing KFKHFM in high load areas and compensating in KFLF if needed .. i find an underscaled load is safer than an overscaled load If you see that going on in a file, it's probably mine  YMMV, i'm sure prj will tell me it is bad practice, but it can also avoid problems with load/ps_w caps on cars not running the 5120 hack. |
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ottosan
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« Reply #6 on: March 01, 2018, 12:07:51 AM »
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Hello, After increasing KFURL by 8% everything vent to normal again. I was assuming that my load problems where there due to turbo that is capable of more flow but I could not see a clear reason. (lack of FR reading for sure)  Anyway I would like to thank you all for your help! There is still one more question I would like to ask you and that is KFVPDKSD and KFVPDKSE. Do I need to touch this maps or no? I'm asking because a tighter gate is installed that opens fully at 0.5 bar. I'm attaching a WOT log from today (8% increased FKURL) and a screenshot of excel table of boost linearization I have made last Saturday. Thank you all in Advance, |
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SB_GLI
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« Reply #7 on: March 01, 2018, 08:59:09 AM »
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I have a habit of slightly numbing KFKHFM in high load areas and compensating in KFLF if needed .. i find an underscaled load is safer than an overscaled load If you see that going on in a file, it's probably mine YMMV, i'm sure prj will tell me it is bad practice, but it can also avoid problems with load/ps_w caps on cars not running the 5120 hack. I do the same, so we can be sucky "tuners" together.  |
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nyet
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« Reply #8 on: March 01, 2018, 12:01:53 PM »
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Do I need to touch this maps or no? I'm asking because a tighter gate is installed that opens fully at 0.5 bar.
Can the car hold rpm stably at part throttle near wg pressure? If not, yes, you might need to adjust it. |
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ottosan
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« Reply #9 on: March 14, 2018, 02:48:44 AM »
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Hello, It's been a while since I reported my progress on issue described. As it turned out the problem is not completely solved. Engine load is still sometimes higher than load request I have adjusted KFVPDKSD/E axis to new gate cranking pressure ratio. What I can tell from logs is, that I'm not over-boosting anymore. Still my engine load is sometimes higher nevertheless I have adjusted KFURL up 10% increased KFPBRK/KFPBRKNW at low load areas as prj suggested. I would like to understand WHY my VE model is not right. So if somebody could tell me what to log and how to understand the core of this behavior I would be very thankful for that. I'm attaching a screenshot of a log taken today. Where you can see the issue I'm reporting above. Your opinion-advice is highly appreciated! Thank you in advance. |
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nyet
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« Reply #10 on: March 14, 2018, 10:53:37 AM »
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I can't make out a damn thing.
Post ecuxplots or the original csvs.
You can always underscale your MAF a bit more.
compare ps_w to actual boost during wot, and see how close they are as a sanity check.
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ottosan
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« Reply #11 on: March 14, 2018, 12:31:46 PM »
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I can't make out a damn thing.
Post ecuxplots or the original csvs.
You can always underscale your MAF a bit more.
compare ps_w to actual boost during wot, and see how close they are as a sanity check.
Thank you for your answer Nyet I will try to log tomorrow as suggested and post CSV. Could you please tell why to underscale MAF? Until now I did't touched MAF. Also it would be great to know what variables to log in addition to what I'm logging right now in order to understand more. My config file is attached. |
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ottosan
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« Reply #12 on: March 16, 2018, 07:16:25 AM »
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I can't make out a damn thing.
Post ecuxplots or the original csvs.
You can always underscale your MAF a bit more.
compare ps_w to actual boost during wot, and see how close they are as a sanity check.
Hello, I'm posting as suggested by Nyet some CSV logs, two of them are normal driving and one is WOT log. Could somebody please look at this logs and tell me what is wrong with the tune. As I said above on part throttle Engine load is more than load request. From my point of view this is the cause of low ignition at this moment. KFURL is modified. Thanks in Advance, |
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SB_GLI
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« Reply #13 on: March 16, 2018, 08:43:03 AM »
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I'm not seeing anything in any of your logs where rl_w > rlsol_w.
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ottosan
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« Reply #14 on: March 16, 2018, 09:40:34 AM »
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I'm not seeing anything in any of your logs where rl_w > rlsol_w.
Hi SB_GLI, Thank you for your Answer. Well that would be great if so. But....Please see attached screenshot. That is just one spot if you look at the files provided, you are going to see that this condition repeats it self. Right now I think that I need to tune KFWDKMSN and it's inverse, because every time it's happening MassAirFlowAtThrottlePlate is lower than MassAirFlow. I might be wrong... Even if I'm right, still don't know how to tune this maps.  Regards |
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« Last Edit: March 16, 2018, 11:50:57 AM by ottosan »
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