igo300
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« on: October 07, 2014, 02:51:01 AM »
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Running RS6 turbos on an RS4
Actual boost meets requested boost (28lbs) but Engine Load (210) not meeting Requested Load (250)
After much reading and searching I'm still lost
Car runs great just like to know if this is a limit in Motronic or something in the map
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phila_dot
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« Reply #1 on: October 07, 2014, 06:14:02 AM »
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Didn't look at your logs, but there's many ways this can happen.
First, keep in mind load realization is calculated and not really regulated, so actual load will not follow desired load perfectly.
Your file is 5120'ed and ps_w isn't capped at 2560 mbar?
My first guess then would be that your MAF may be slightly underscaled.
Does plsol_w == pssol_w?
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nyet
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« Reply #2 on: October 07, 2014, 10:23:59 AM »
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Agree 100% with phila.
In fact, unless you can find other real problems, having load not meet requested isn't a bad thing.
IMO having load close to correct in idle in part throttle is far more important than at WOT.
And even then, having load consistently under requested isn't a bad thing.
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igo300
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« Reply #3 on: October 07, 2014, 12:38:49 PM »
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Agree 100% with phila.
In fact, unless you can find other real problems, having load not meet requested isn't a bad thing.
IMO having load close to correct in idle in part throttle is far more important than at WOT.
And even then, having load consistently under requested isn't a bad thing.
Do you mean load close to "correct"ed or requested in the line above. Attached is an image of the various loads. Your comments would be much appreciated. |
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nyet
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« Reply #4 on: October 07, 2014, 12:52:14 PM »
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I think you're fine, as long as idle load looks close to stock.
Before I go further, lets make sure we are on the same page:
The problem is the ECUx aliases are mostly misnomers, but they persist because people are used to using them (which makes purists cringe)
In this case:
EngineLoadCorrected - rlmax
EngineLoadSpecified - rlmx
EngineLoadRequested - rlsol
rlmx is "corrected" (by IAT, etc) to generate rlmax, which caps rlsol (which is the driver requested load)
The only one that matters in this context is rlsol.
LoadCorrected/LoadSpecified should really be renamed to EngineLoadRequestedCap and EngineLoadRequestedCapCorrected or something.
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carsey
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« Reply #5 on: October 07, 2014, 06:04:01 PM »
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Had a quick look from one of the logs I managed to work out in your CSV as there was a few, and could see ECU pulling throttle back around 2500rpm and also 5750rpm. Something is causing it to drop off after 5700rpm....quite a bit.
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nyet
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« Reply #6 on: October 07, 2014, 06:36:13 PM »
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Had a quick look from one of the logs I managed to work out in your CSV as there was a few, and could see ECU pulling throttle back around 2500rpm and also 5750rpm. Something is causing it to drop off after 5700rpm....quite a bit.
Yes, that would be him letting off the throttle  Also, you should really log ps_w... you are running WAY PAST the MAP limit which is not a good idea unless you know what you are doing. |
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igo300
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« Reply #7 on: October 07, 2014, 07:01:29 PM »
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Had a quick look from one of the logs I managed to work out in your CSV as there was a few, and could see ECU pulling throttle back around 2500rpm and also 5750rpm. Something is causing it to drop off after 5700rpm....quite a bit.
Thanks for taking the time to look at these. I think the big drop at 5700 on the first run was me running out of road and jumping on the anchors. I'm still trying to work out the load from the S4 Wiki calculation. |
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nyet
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« Reply #8 on: October 07, 2014, 07:08:44 PM »
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Thanks for taking the time to look at these. I think the big drop at 5700 on the first run was me running out of road and jumping on the anchors.
I'm still trying to work out the load from the S4 Wiki calculation.
Forget worrying about load right now, you need a plan of action before doing anything else. It doesn't look like you have a plan... stop tuning immediately. What pressure are you planning on running? If past 2550 mbar, you need to rethink what you are doing, and you'll need an external boost gauge, or you have to run the 5120 hack. If not past 2550 mbar, your WGDC is completely ridiculous... not sure what you did with the PID, but it isn't even remotely right. |
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nyet
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« Reply #9 on: October 07, 2014, 07:10:45 PM »
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Actual boost meets requested boost (28lbs)
Requested boost is not 28lbs. Step back. Something is very not right with your approach. |
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igo300
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« Reply #10 on: October 07, 2014, 08:09:14 PM »
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Forget worrying about load right now, you need a plan of action before doing anything else. It doesn't look like you have a plan... stop tuning immediately.
What pressure are you planning on running? If past 2550 mbar, you need to rethink what you are doing, and you'll need an external boost gauge, or you have to run the 5120 hack.
If not past 2550 mbar, your WGDC is completely ridiculous... not sure what you did with the PID, but it isn't even remotely right.
I'm not tuning this. It has been done by a very experienced tuner. Runs like clockwork and has done for 18 months. DD, trackwork, etc 2.5 FATS and over 500WHP. I do run Zeitronix and it does runs 28lbs - 26lbs at redline. I'm just trying to understand the logs and tuning generally so from your comments I guess there are many ways to approach tuning. |
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nyet
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« Reply #11 on: October 07, 2014, 09:51:56 PM »
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You're not going to be able to make head or tails of anything you log from that tune  Anything past the MAP limit is going to be a huge hack. |
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igo300
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« Reply #12 on: October 07, 2014, 09:57:21 PM »
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You're not going to be able to make head or tails of anything you log from that tune Anything past the MAP limit is going to be a huge hack. Bummer. Was hoping to get some insight from a practical perspective. Guess I'll have to do with high power (not complaining) - but will watch with interest as the Community project progresses and hope to contribute down the line with some logs as my daughter has an S4 (but with bigger injectors running E85). |
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nyet
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« Reply #13 on: October 07, 2014, 10:30:18 PM »
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Never a good idea to try to learn from somebody else's tune, especially in this case, where it is going to be a big hack. Not that they did it wrong, but that you'll never know all the random crap they did to get it working right.
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Lost
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« Reply #14 on: October 11, 2014, 01:59:35 AM »
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I think you're fine, as long as idle load looks close to stock.
Before I go further, lets make sure we are on the same page:
The problem is the ECUx aliases are mostly misnomers, but they persist because people are used to using them (which makes purists cringe)
In this case:
EngineLoadCorrected - rlmax
EngineLoadSpecified - rlmx
EngineLoadRequested - rlsol
rlmx is "corrected" (by IAT, etc) to generate rlmax, which caps rlsol (which is the driver requested load)
The only one that matters in this context is rlsol.
LoadCorrected/LoadSpecified should really be renamed to EngineLoadRequestedCap and EngineLoadRequestedCapCorrected or something.
This is a really good explanation. Is it possible too use this way of "explanation" in Wiki? I am thinking the way you used to describe this. What is actually depending on what and what the output is. Did it make any sense?? |
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