closed loop boost control aka Boost kpa targets
#1
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closed loop boost control aka Boost kpa targets
Has anyone had success with the Boost kpa target table 1?
Meaning got rid of the oscillation when controlling boost with that option instead of the duty targets table.
I hate the idea that my boost control is so temperature dependant.
or is it a processor speed limitation of the MSI?
Meaning got rid of the oscillation when controlling boost with that option instead of the duty targets table.
I hate the idea that my boost control is so temperature dependant.
or is it a processor speed limitation of the MSI?
Last edited by paul; 07-26-2008 at 09:58 PM.
#2
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I also have the problem with temp, when it gets below 60 degrees I overboost bad, I would love the closed loop to work. I cant figure out the closed loop, like you said nomatter what I tried it would keep oscillating and just acting weird.
#3
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Paul,
my experience is that it will over and under shoot target boost in a sine wave type pattern, no different than closed loop fueling. Must use the same algorithms. I recommend avoiding it.
my experience is that it will over and under shoot target boost in a sine wave type pattern, no different than closed loop fueling. Must use the same algorithms. I recommend avoiding it.
#4
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hmmm http://www.msextra.com/ucp.php?i=pm&mode=view&p=62556
edit for correct link. that link is to the post only. here is the thread. http://www.msextra.com/viewtopic.php...st=0&sk=t&sd=a
edit for correct link. that link is to the post only. here is the thread. http://www.msextra.com/viewtopic.php...st=0&sk=t&sd=a
#8
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The open loop EBC code is considered to be fairly stable code by the developers, though the closed loop code is considered experimental- They'll do more with the MS2 with the additional hardware resources they have I'm sure, however the MS1E closed loop EBC always has been experimental code and I've never bothered to try and dial it in to perfection, though I've always been very happy with the open loop EBC functionality. I get slight (1psi or so) boost increase on a cold day, but in my case at least, it doesn't hurt me any as I've laid out my tables with this in mind, and the cooler air is less detonation prone to boot. If it was 3-4 psi I'd be concerned, and different setups may vary. In my config I see about 1psi or so and it has never been an issue.
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'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
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Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
#9
Stupid noob question, What is the difference between open and closed loop?
From what I vaguely remember it was the difference between the MS using gego correction against the fuel table and not. But I have no idea what it means when in reference to EBC.
I have my DC table setup perfectly, but like some here on colder days it spikes. Using boost targets would be pretty slick.
From what I vaguely remember it was the difference between the MS using gego correction against the fuel table and not. But I have no idea what it means when in reference to EBC.
I have my DC table setup perfectly, but like some here on colder days it spikes. Using boost targets would be pretty slick.
#10
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Open Loop means the boost duty cycle is static based on a table. The ECU is not trying to read what the current boost level is in real time and target a certain amount of boost.
Closed loop means that the ECU is not targeting a static duty cycle, but instead has a table programmed to allow it to target boost levels at different areas of the tables and dynamically attempt to adjust duty cycle of the EBC valve to attain the desired amount of boost on the fly. The 'loop' is closed as it's reading from the sensor, and using this data to determine how it controls the EBC valve, which is turn effects how much boost is made, which effects the reading at the sensor that it again reads, makes another adjustment if needed, etc, in a constant loop.
Closed loop means that the ECU is not targeting a static duty cycle, but instead has a table programmed to allow it to target boost levels at different areas of the tables and dynamically attempt to adjust duty cycle of the EBC valve to attain the desired amount of boost on the fly. The 'loop' is closed as it's reading from the sensor, and using this data to determine how it controls the EBC valve, which is turn effects how much boost is made, which effects the reading at the sensor that it again reads, makes another adjustment if needed, etc, in a constant loop.
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Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
#11
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open means it simple reads your DC% map and controls the solenoid to your table exactly.
close loop means it reads your kPa targets table and your current conditions and tries to control the valve on the fly to achieve and maintain your target.
#13
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Considering we have 20+ degree differential throughout the day this time of the year in NJ I get a bigger change in my max boost than just 1psi so I was hoping to find a way to make KPA targets work better.
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