Help with PID tuning (logs inside)

Sava666

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Dec 14, 2020
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Good day, folks.

I'm doing self tuning. Almost got everything in place except the throttle closures and weird boost line. Somehow related with P tuning. I didn't get what is the x axis is? Any one can provide clear instructions based on logs?

What I'm trying to achieve is a flatline 18.5 psi but I see that WGDC after PID is damn close to the BASE.

Shoud I down BASE or Should I work out this with P?

Thanks!

@carabuser @RSL @all4bspinnin
 

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  • 2022-05-19 01_32_06 I8A0S v4_corrP.bin.csv
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  • 2022-05-19 01_38_04 I8A0S v4_corrP.bin.csv
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carabuser

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Oct 2, 2019
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P factor and base won't alter the boost target.

If you want boost target to stay at 18.5 regardless then set boost limit multiplier to 4, load limit factor to 0.3, load target to 327 and boost ceiling to 18.5PSI.
 

wheela

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Jun 4, 2021
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P factor and base won't alter the boost target.

If you want boost target to stay at 18.5 regardless then set boost limit multiplier to 4, load limit factor to 0.3, load target to 327 and boost ceiling to 18.5PSI.
I'm curious, what is the significance of 327? Is that the highest value you can enter into the cell? Basically setting the load target arbitrarily high enough so that it will never target a boost below the 18.5psi boost ceiling? Same for the other two items mentioned?

PS - sorry for the nube-ish question
 

carabuser

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I'm curious, what is the significance of 327? Is that the highest value you can enter into the cell? Basically setting the load target arbitrarily high enough so that it will never target a boost below the 18.5psi boost ceiling? Same for the other two items mentioned?

PS - sorry for the nube-ish question
Yes, just max values for everything.

The boost target will then cap out at the ceiling value before going forward. There will still be some reductions afterwards but if it'll be close enough.

I don't recommend doing it though. You should shape the load curve to match what the engine is able to fulfil. No point to target 18.5PSI at 7k on stockers as you'll likely only make 13.
 
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Sava666

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Dec 14, 2020
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P factor and base won't alter the boost target.

If you want boost target to stay at 18.5 regardless then set boost limit multiplier to 4, load limit factor to 0.3, load target to 327 and boost ceiling to 18.5PSI.
No, my target is flat. I want my TCs gone and boost mean line flat as possible. As I see P error goes negative, and mean climbs up. What part of P factor table should be touched?
 

carabuser

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Oct 2, 2019
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Depends what your curve looks like. You can embed the logs using the built-in charting function in the forum.

Best to start by copying the PID parameters from an INA0S bin as they work much better as a base than what comes standard in other ROMs. I've never had to adjust the P factor in INA0S, they got it spot on.
 

Sava666

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Dec 14, 2020
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Depends what your curve looks like. You can embed the logs using the built-in charting function in the forum.

Best to start by copying the PID parameters from an INA0S bin as they work much better as a base than what comes standard in other ROMs. I've never had to adjust the P factor in INA0S, they got it spot on.
 

Sava666

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Sava666

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corbanistan

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Jul 26, 2021
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Depends what your curve looks like. You can embed the logs using the built-in charting function in the forum.

Best to start by copying the PID parameters from an INA0S bin as they work much better as a base than what comes standard in other ROMs. I've never had to adjust the P factor in INA0S, they got it spot on.
Read somewhere that they changed the way PID works slightly from MSD80 to 81 so P-factor shouldn't be copied if on I8A0S. Any truth to this?
 

Sava666

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Dec 14, 2020
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Im slightly moving my P table back and forth, but things never change. Guess I have to play with Dfactor to raise it little bit against Base? Any ideas?

Also will try Inaos.
I tried to lower a bit Base table and it helped with TCs but I don't want to happen since it drops boost.
 

wheela

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Jun 4, 2021
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Here's a graphic showing how P, I, and D influence response of control systems in general. P-term speeds up response (actual hits target faster), but can cause over-shoot. I-term eliminates offset between the actual and target, but can also contribute to over-shoot. D-term acts as a damping factor on the response to tame over-shoot and ringing, but too much D-term can slow response.
 

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  • PID_Compensation_Animated.gif
    PID_Compensation_Animated.gif
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Sava666

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Dec 14, 2020
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Here's a graphic showing how P, I, and D influence response of control systems in general. P-term speeds up response (actual hits target faster), but can cause over-shoot. I-term eliminates offset between the actual and target, but can also contribute to over-shoot. D-term acts as a damping factor on the response to tame over-shoot and ringing, but too much D-term can slow response.
This not giving me any hint to be honest. Can you elaborate on how to raise after pid against wgdc base?
 

carabuser

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Oct 2, 2019
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This not giving me any hint to be honest. Can you elaborate on how to raise after pid against wgdc base?
That's exactly the information you need. If you don't understand how a PID operates then we can't help.

Honestly looking at those logs you are best to just find a tuner or use an OTS map.
 

Sava666

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Dec 14, 2020
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That's exactly the information you need. If you don't understand how a PID operates then we can't help.

Honestly looking at those logs you are best to just find a tuner or use an OTS map.
I've tried coupe of tuners they aren't fit my requirements. Better to make it DiY. Can you tell me what's wrong? You mean the boost control part? Tune is made by your recommendations, all across different boards )
 

Sava666

Corporal
Dec 14, 2020
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Lots of people say that its better to zero out PID and to sort out base table. Is this reliable info?
 

Sava666

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Dec 14, 2020
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So I have reverted back for couple of revisions and applied INA0S PID but nothing much changed. Curious it is not PID related then what it can be? Any ideas?

INA0S PID
 

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  • 18psi_v1.1_city_PIDinaos.bin
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Sava666

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Dec 14, 2020
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This is stock PID. Board is allowing only one graph per message.

 

Sava666

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Dec 14, 2020
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I'm trying to understand wether I need to make wgdc base table areas (TCs) lower by 10% or should I raise ceiling and play with blm?
 

carabuser

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Oct 2, 2019
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The over boost looks like it's being caused by too much base. What do your two adder tables look like? The airflow and PID one.

The INA0S PID was working fine but i suspect the adder is low so it has little weighting. The airflow adder might be too high also. Either that or the base table is way over.
 
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