MS EBC Duty Cycle question - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

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Old 05-08-2014, 10:02 AM   #21
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you also should be hooked up in a way that 0% duty cycle = wastegate and only anything about that adds boost.

otherwise this suggests the MS has to be running in order to run wastegate and if the solenoid/ms fails you will overboost.

when the solenoid is depowered you should be able to bloe directly through it to the wastegate actuator. in turn, this will open the wastegate. So if the solenoid fails, which they do, it will default to wastegate pressure.

when the MS rapidly toggles ground, only then should you raise boost.

p0i0d0 should overboost intensely.
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Old 05-08-2014, 10:22 AM   #22
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Quote:
Originally Posted by mlev View Post
I set up my EBC last night. I have heard "you don't want to make it so that MegaSquirt has to intervene in order for your wastegate to open" which makes perfect sense...

I hooked up my EBC (DIY Auto Tune one) according to the directions on DIY Auto Tune...and then tested by blowing into one end of the EBC. with no power hooked to the EBC, air flowed through correctly from one barb to the other, and the 3rd hole (with no barb) was blocked...
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Originally Posted by Braineack View Post
you also should be hooked up in a way that 0% duty cycle = wastegate and only anything about that adds boost.

otherwise this suggests the MS has to be running in order to run wastegate and if the solenoid/ms fails you will overboost.

when the solenoid is depowered you should be able to bloe directly through it to the wastegate actuator. in turn, this will open the wastegate. So if the solenoid fails, which they do, it will default to wastegate pressure.

when the MS rapidly toggles ground, only then should you raise boost.

p0i0d0 should overboost intensely.

Duuuudeee.
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Old 05-08-2014, 10:26 AM   #23
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dont ever assume I read.


can you even in OL mode, set your DC to say 50% and hear it cycling?
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Old 05-08-2014, 11:44 AM   #24
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Quote:
Originally Posted by mlev View Post
Sorry, beating a dead horse here, but this isn't true for me. At least not with the default settings.

Am I supposed to have the polarity set to "Normal"? Because it defaults to Inverted.

As of right now I'm still running open loop...Duty Cycle - 100 I'm at WG pressure. I dropped Duty Cycles to 70 across the board (basically using my ebc as an mbc kindasorta) and i hit about 9-10psi pretty consistantly on a 6psi wg.
I have not personally put my ear on the solinoid, but based on the above information I assume it is cycling correctly.
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Old 05-08-2014, 03:18 PM   #25
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Ok, so I switched back to open loop and then switched my polarity to "normal" and now 0 duty cycle is WG pressure. 35% duty cycle had me holding about 9psi after spool.

I read through the prior linked thread on the new CL PID EBC tuning and i'll give it a shot this evening after work.
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Old 05-08-2014, 05:18 PM   #26
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So when you say switch polarity, are you swapping the +12V and ground wires or is there a simple setting to reverse?

EBC noob I is. Just got my DIYAutoTune unit too and will be setting it up soon. 'Scribin for your eventual success to mirror.
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Old 05-08-2014, 05:23 PM   #27
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I mean the "polarity" setting under the boost control settings in tunerstudio/megasquirt.

I _believe_ all it actually does is change the way that MS reads the numbers.

For example, when my polarity was "inverted" and my duty cycle was 100 I was at WG pressure. When my polarity was "normal" and my duty cycle was 0 I was at WG pressure.
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Old 05-08-2014, 05:31 PM   #28
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Looks like you are on the right track mlev. I switched to open loop because I couldn't get closed loop working to my satisfaction and I wanted a fall-back solution until I got it right.
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Old 05-08-2014, 06:18 PM   #29
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OK sweet that's a simple enough fix. I'm really excited for the spooling goodness of the EBC but it sounds like everyone has teething issues setting it up just right, open loop delivers variable pressures, and closed loop transitions are tricky. I've read hornetball's threads but still.

My MS1 will undoubtedly make it even easier lol.
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Old 05-08-2014, 08:01 PM   #30
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This is ******* stupid and i'm about ready to switch back to open loop.

In open loop 100% duty cycle is now infinity pressure (closed solinoid) and 0% duty cycle is now WG pressure (4-5psi on a 6psi WG after pressure loss). 35% duty cycle holds me pretty steady at about 9psi.

CLOSED LOOP: I have my polarity set to Normal, with P100,I0,D0. To the best of my knowledge that should be WG pressure, right? Wrong.



I spool up to about 11 1/2 PSI before lifting. 180ish kpa. My target boost is 150kpa across the board btw.

In my log file it looks like my boost duty cycle goes from 0 to 100 right around 112 kpa.

What am I missing here?

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MS EBC Duty Cycle question-logged-pull.png   MS EBC Duty Cycle question-boost-control-settings.png  
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Old 05-08-2014, 08:17 PM   #31
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Do I need to flip-flop my closed duty % and open duty %? Would be stellar if there was some documentation on this.
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Old 05-08-2014, 09:44 PM   #32
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I'm glad you're doing this closed loop stuff. I was just about to do it and only barely figured out how my wastegate was acting up when I went over certain boost levels, between that and the whole 0 = 100, 100 = 0 thing I spent two weeks doing open loop.

Based on what you are seeing it seems like you need to go with the instructions they have here where PID starts off at 0 across the board? Or is the firmware not new enough?

Megasquirt MSEXTRA / MS3EFI • Boost control change testing (MS2 and MS3) (View topic)
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Old 05-08-2014, 10:10 PM   #33
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Where is this "initial value" table they keep talking about?
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Old 05-08-2014, 11:43 PM   #34
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Initial values table must have been added after your firmware version.



Quote:
5. Boost Control
To make things more intuitive we have now changed the firmware so that
- "Normal" is the most typical output polarity setting
- larger boost duty% numbers mean more boost.

If you are upgrading from a previous firmware version, then the Boost Output polarity setting will be the opposite. For most users it will now be "Normal".
This is true whether using open- or closed-loop boost control.

If you are using closed-loop, you will need to retune your PID settings and alter the sensitivity slider as required.

Open loop boost users most likely need to set their table so that:
new_cell_value = 100 - old_cell_value

Remembering that more duty = more boost.

I still say you should be set to normal polarity. What happens if you set P to 0?
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MS EBC Duty Cycle question-qk4vuil.png  
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Old 05-09-2014, 02:25 AM   #35
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Show us your boost target and initial value tables...
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Old 05-09-2014, 08:15 AM   #36
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Quote:
Originally Posted by mlev View Post
My target boost is 150kpa across the board btw.
Quote:
Originally Posted by mlev View Post
Where is this "initial value" table they keep talking about?
I'll try updating my firmware this weekend, but I'm on 3.3.0 so idkwtf.
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Old 05-09-2014, 09:54 AM   #37
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it's an MS3 thing. I forget people still even run ms2. (ms2 got the initial duties thing in one of the 3.3.2 betas)


You should be using the 35% freq. value for the DIY solenoid.

and try starting at P 200.


also...do you have overboost protection on? another ms3 thing, CL won't work without overboost turned on.

Last edited by Braineack; 05-09-2014 at 10:10 AM.
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Old 05-09-2014, 10:33 AM   #38
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Quote:
Originally Posted by Zaphod View Post
Show us your boost target and initial value tables...
Boost target is 180kpa everywhere. Initial value is pretty much a guess based on a couple pulls with open loop enabled and 100% untested. I expect lots of tweaking will be needed. But I just noticed timing is stuck in fixed mode so that needs to be worked out first.
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Old 05-09-2014, 10:46 AM   #39
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Quote:
Originally Posted by Braineack View Post
it's an MS3 thing. I forget people still even run ms2. (ms2 got the initial duties thing in one of the 3.3.2 betas)


You should be using the 35% freq. value for the DIY solenoid.

and try starting at P 200.


also...do you have overboost protection on? another ms3 thing, CL won't work without overboost turned on.
Thanks Brain, I'll give it a shot. I didn't even realize I could do 200%...?

I have a feeling I'll end up building an ms3x here pretty soon...
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Old 05-09-2014, 03:34 PM   #40
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That's the other thing I was thinking last night, you might have to go to 200% for P. Makes little sense when they list it as a percent value.
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