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-   -   EBC duty cycle never changes (https://www.miataturbo.net/megasquirt-18/ebc-duty-cycle-never-changes-86818/)

whinin 11-28-2015 11:23 AM

EBC duty cycle never changes
 
So I'm trying to get the EBC going. I have it in open loop. I have tried normal and inverted polarities, with both 100% open AND closed, and 0% open AND closed. Yet, no change in boost, boost duty cycle stays at 35% at full tilt, which is what the initial value table is set to. But I have it in open loop, and that table is greyed out. So I'm kind of lost....

Any helps? ms3x running the DIY solenoid.

whinin 11-28-2015 11:30 AM

2 Attachment(s)
https://www.miataturbo.net/attachmen...ine=1448728216


https://www.miataturbo.net/attachmen...ine=1448728216

Left is settings at normal, 100% and 100%. Right is inverted, 40% and 40%

stefanst 11-28-2015 01:10 PM

It's doing exactly what you're telling it to do. 35% duty cycle as per your settings.
Are you possibly confusing open and closed-loop? Because it sounds like your complaining about closed loop not working while you have it set to open loop.

whinin 11-28-2015 02:49 PM

I thought open loop doesn't use initial duty tables? I'm trying to get my ebc duty values. I haven't touched closed duty yet



Originally Posted by stefanst (Post 1287357)
It's doing exactly what you're telling it to do. 35% duty cycle as per your settings.
Are you possibly confusing open and closed-loop? Because it sounds like your complaining about closed loop not working while you have it set to open loop.


acedeuce802 11-28-2015 03:20 PM

Not sure where the misunderstanding is, but look at the table you have there. Boost Control Duty 1. This is the ONLY factor in open loop control. If you're at full throttle, you're at full load, and your boost duty is in the top row. That row is all 35.

whinin 11-28-2015 03:41 PM

Ok. I thought under open loop it doesn't use the initial duty table. I will make the changes! Thanks for the help. Should be able to get it from here.


Originally Posted by acedeuce802 (Post 1287384)
Not sure where the misunderstanding is, but look at the table you have there. Boost Control Duty 1. This is the ONLY factor in open loop control. If you're at full throttle, you're at full load, and your boost duty is in the top row. That row is all 35.


acedeuce802 11-28-2015 04:12 PM

They are two different tables.

Open loop means: Megasquirt see's you're at 5500 RPM and 100% throttle, so it looks at the Boost Control Duty 1 table and sets your EBC DC at 35 because that's in the cell.

Closed loop means: Megasquirt see's you're at 5500 RPM and 100% throttle, so it looks at the initial value table and sets your EBC DC at 35 because that's in the cell. It then looks at your desired boost level table, and see's that 5500 RPM and 100% throttle desires 180 kpa. Then it looks at your map sensor and realizes that the 35% that it commanded only nets you 178 kpa, so it bumps the DC up slightly to achieve that.

Cliffs: closed loop uses feedback, open loop doesn't.

shuiend 11-28-2015 04:22 PM

What firmware are you on? If not running 1.4 then you need to update to it before continuing to tune EBC.

whinin 11-28-2015 04:56 PM

You guys are awesome. I understand completely now.

I updated it around a year ago. Not sure, don't have my laptop with me right now. Will check when I get home.

Savington 11-28-2015 05:30 PM

1.4.0 was released a few months ago. Update before continuing to tune.

whinin 11-28-2015 05:40 PM

:bigtu: ty!


Originally Posted by Savington (Post 1287397)
1.4.0 was released a few months ago. Update before continuing to tune.


whinin 11-28-2015 09:38 PM

OK. Updated to 1.4v firmware. Most of the settings migrated over, just had to re-enable closed loop idle control. So question, in open loop, to find my duty cycle values where the EBC starts to affect psi, I need to 0 out the initial duty table right? Then increase by 5-10% until I see a change? Then do so at 100% going down 5-10%? Kind of like how you would find the duty cycle for the IAC?

acedeuce802 11-29-2015 12:05 AM

The easiest way is to tune open loop first. Start with 0 DC, then increase by 5-10 until you're close to your target. Then dial it in by increments of 1. Your initial value table isn't a range like the IACV is. Then once the open loop runs fine, then use those values for the initial value table, and tune closed loop.

aidandj 11-29-2015 10:40 AM

Yes you are correct on how to find the min and max values for EBC. But you have a lot more reading to do. Go read the instructions on tuning boost control. And search for EBC on this forum. Then come ask again.

whinin 11-29-2015 11:27 AM

I did plenty of reading a link you posted in another thread. link

I got my target psi in open loop, faded the tables down, copied them over to the bias tables, and changed to closed loop setup mode. It hits 170kpa and stays within 5kpa the whole time. It oscillates a bit, but I can tune that out with either the slider or PID. I have developed sync issues, I have red vertical lines in MLV where it didn't capture the log. I will be deleting the driver for my serial to usb and re installing hoping that fixes it. Then I will be able to get a good log on it.

aidandj 11-29-2015 11:37 AM

:bigtu: You're on the right track.

whinin 11-29-2015 01:43 PM

1 Attachment(s)
https://www.miataturbo.net/attachmen...ine=1448822619

Think I got setup mode pretty dang close. Target is 170kpa. Now onto basic mode.


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