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Old 04-01-2016, 03:14 AM   #1
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Default Closed loop boost control starting numbers

I've tuned open loop, ran this for 4 years. Max boost I look for is 12psi
Interested in trying closed loop but after several failed attempts thought it was worth asking for help.
I've a ms2 rev enhanced ecu, FM2 turbo set up on a 1.8.
Does anyone running a similar set up on closed loop boost control have a basic set of numbers I can start on ?
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Old 04-01-2016, 03:21 AM   #2
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It's different for every setup. You need to tune.
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Old 04-01-2016, 08:48 AM   #3
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Quote:
Originally Posted by aidandj View Post
It's different for every setup. You need to tune.
Ok, but ......

Is there at least a starting point?
PID values ?
I had these numbers but they were from another guys set up and the car keep overboosting cutting.
My open loop map is fairly good so I figure if I can get close with PID and start dropping P until it stops over boosting I'm heading in the right direction.

P=145
I=40
D=100

Do you start at 0-0-0 or 100-0-0 or 100- 50-0 ?
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Old 04-01-2016, 12:26 PM   #4
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this may help or it may not
PID for Dummies - Control Solutions
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Old 04-01-2016, 12:33 PM   #5
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Quote:
I had these numbers but they were from another guys set up and the car keep overboosting cutting.

P=145
I=40
D=100

Do you start at 0-0-0 or 100-0-0 or 100- 50-0 ?
I'm surpirsed you even got past wastegate with those settings, sometimes tells me you dont even have your EBC plumbed/configured properly in the first place.

start at 100-0-0.
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Old 04-01-2016, 12:57 PM   #6
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Quote:
Originally Posted by Braineack View Post
sometimes tells me you dont even have your EBC plumbed/configured properly in the first place.
Not sure if he was using those settings before or after he moved the EBC source to pipe before TB. Also known as 'B' from Joe's you don't need EBC thread.

Currently his setup is charge pipe before TB -> EBC -> Wastegate
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Old 04-01-2016, 01:08 PM   #7
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Quote:
Originally Posted by Braineack View Post
I'm surpirsed you even got past wastegate with those settings, sometimes tells me you dont even have your EBC plumbed/configured properly in the first place.

start at 100-0-0.
Just a quick question before I start, I've got boost protection set up. Works fine with my open loop tuning.
So here's what I had my settings at for open loop control
<br >

This is now my closed loop, just changed the PID settings to my starting numbers. Am I right in that's all I need to change to get started ?


<br >
Attached Thumbnails
Closed loop boost control starting numbers-80-image_c108b1b3d94a4dce03a16d7df316f3b2fcceeb8d.jpeg   Closed loop boost control starting numbers-80-image_283b08b4a99b78e222efbf4258c60c8611785e84.jpeg  
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Old 04-02-2016, 02:40 PM   #8
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Followed the guide below with settings
P = 100
I = 0
D = 0

Held it at 2000rpm Wot runs in 3rd

No matter what I lowered P to nothing changed. Fairly slow spool up gets the wastgate.
The boost duty figure is changing but the same with any PID number.

Followed these guidelines:

Set Integral and Differential Gains to 0% - To make tuning the Proportional gain easier, set the Integral and Differential gains to 0%.
Set Proportional gain to 150% and slowly lower - While tuning Proportional gain, higher numbers mean slower boost climb and lower final boost. For safety, start with a very high gain (150% should be sufficient). Find the RPM that typically spools quickly, and fully and quickly depress the accelerator. Note how much boost is reached. If boost overshoots the target, increase the Proportional gain. Otherwise, reduce the Proportional gain and try again. Do this until boost reaches the target with little or no overshoot.


Switched back over to open loop and all back to normal working from my OL boost control duty table spools upto target 10psi
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Old 04-03-2016, 12:21 PM   #9
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so you could go to 0-0-0 and not get any boost above wastegate?
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Old 04-03-2016, 03:07 PM   #10
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Quote:
Originally Posted by Braineack View Post
so you could go to 0-0-0 and not get any boost above wastegate?
I'll give it a go tonight, hadn't realised it would make any difference after dropping it so much with no effect.
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Old 04-03-2016, 04:33 PM   #11
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yeah youll need to drop P closer to 15-10 or so before you start seeing boost going above the wastegate and approach the target.
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Old 04-04-2016, 03:25 PM   #12
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Quote:
Originally Posted by Braineack View Post
yeah you'll need to drop P closer to 15-10 or so before you start seeing boost going above the wastegate and approach the target.
That worked, ended at 10.0.0 and it hit the target. Dropped 8.0.0 and it overshot.
Then started tweaking I and went to 10.05.0 and it overshot
Went to 10.02.0 and it overshot
Went to 10.01.0 and it didn't seem to change anything
Ended up back at 10.0.0

Log attached
Attached Files
File Type: msl 10_modified.msl (39.9 KB, 32 views)
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Old 04-04-2016, 03:30 PM   #13
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Glad to see the progress...

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Old 04-04-2016, 05:53 PM   #14
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Logging - Can anyone confirm if my goal is to get my MAP to be matched with the my Boost Target, as much as possible. If that's correct how close should I be aiming for, whats achievable ? Thanks
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Old 09-26-2017, 09:53 AM   #15
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Got back onto this after a year hill climbing the car in England.
Found an old thread from Braineack and did the following:

1) Ran some WOT runs in 2nd gear with no boost control to get the wastegate pressure which on mine is 9psi (approx 165 MAP)
2) Set the boost control to closed loop and the rate to 40
3) Set the boost target table to a higher pressure than wastgate - 185 MAP (approx 12 psi)
4) Set P.I.D to 200.0.0
5) Ran 2nd gear pulls nice and steady and allowed boost to build the revs
6) Checked the log to see if the MAP was getting close to target boost.
7) Repeated steps 5 & 6 and reduced P until it overshot slightly.... on mine it was 11.0.0
8) Next step I believe is to increase I until it maintains the boost target better, oscillation to be tuned out with D. Will try again at the weekend.

What I like about the open loop is that it appears to give a consistent boost level through the gears and doesn't fluctuate by +2 psi dependent on ambient temps.
Previously if my target was 14psi I had to tune this for 4th gear pulls which gave me about 11psi in 2nd gear. Seems not to vary with closed loop.
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