I am having an EBC issue that I cannot find a solution for using google/this site. My CurrentTune is attached.

Car setup:
- MS3x (1.4.0 release)
- TunerStudio (3.0.28)
- DIYautotune EBC kit
- boost control enabled, Tuning Mode = Advanced (see full settings below)

When tuning EBC, changes I make to the PID values seem to make no difference in turbo spool or boost levels. I can set the P value to 25 or 150 and it makes no difference in turbo spool rate or final boost level. However, very small changes to the sensitivity slider (485-500) take me from not even meeting targets to hitting overboost protection very quickly after full throttle application. Is there something wrong with my settings that would be causing this issue?

P = 100, I = 0, D = 0, and Sensitivity = 485
- boost stays around 9-10psi to redline from a pull starting at 3500RPM (target boost gets up to 13psi by redline)

P = 100, I = 0, D = 0, and Sensitivity = 490
- boost hits the overboost protection limit of 195kPa very quickly after full throttle application at 3500RPM

Boost Control Settings



Boost Control Target Table

 

Post your initial values table.

 

https://www.miataturbo.net/megasquir...7/#post1465372

We have a thread for this.
Your target table needs work. Take a look at the post I linked.

 

yes we do

 

Sorry about that, I did search but did not find that thread. Thank you!

 

And does that get you close when you run open loop?

Dann

 

Yes. I started in open loop and copied the open loop duty cycle values to the initial value table once I switched to closed loop.

I think the thread by 18psi that leboeuf linked is going to help a lot. I wish I had found that sooner. I will update here after work today once I have had a chance to do some tuning.

 

I read through 18psi's EBC thread linked above. I am well ahead of where I was a week ago.

However, I am having an issue that I cannot figure out. When I was dialing everything in, I found that my car ignores the lower limit delta and activates EBC as soon as manifold pressure passes 100 kPa. Below is a data log where I set my targets all to 190kPa and my EBC Lower Limit Delta to 20kPa. As you can see, EBC activates as soon as MAP reaches 100kPa, not 170kPa as it would if it were following the EBC Lower Limit Delta.

One other thing that is confusing me, if EBC Duty Cycle = 100, doesn't that mean the valve is closed (fastest possible spool)? The data log shows that Duty Cycle goes from 0 to 60 (60 is my Max. Duty %) and not from 100 to 60.

 

If this should be going in 18psi's thread let me know. I was not sure which place would be more appropriate.

 

I went out a few more times since posting and changed around some settings. I still have not found a solution to the EBC Lower Limit Delta problem that I posted about above.

Has anyone encountered this problem before?

 

I made mine about 90, so it never really occurs. I have very aggressive settings otherwise, and I get all the fast gain I need. Then I tend to get less overshoot because the PID is controlling all the time, not only when boost is within 30 (to use your value posted above).

You are also mis-understanding the lower control value. It means go directly to 85% DC until you are within 30 (or 20, your newer number) of target.

Don't go smaller, go bigger.

 

Your not understanding how lower limit delta and the 100kpa line works.

Your EBC is SUPPOSED to be at 100% after 100kpa UNTIL you hit to 20kpa below your target. At that point, assuming you are in "setup" mode, your EBC would default to whatever your bias table said was the proper boost duty in order to attain your target.

If you are running basic or advanced, the megasquirt will adjust your EBC duty in order to reach your target.

I'll look at your log/tune in a few.

 

Ok, IF that log was done on the tune you posted I am at a loss.

First, your TPS is all screwy. Do you have a variable TPS installed? You pretty much jump between 0-5% and 99%. Acceleration doesn't seem to be tied to TPS at all. You go "full throttle" for .3 seconds. Then sit at 0-20%. Something isn't right here.

Second, your Boost Duty is showing 60% or ZERO. And your boost target is shown yo be 190kpa at all times. That doesn't cross with how closed loop boost works in my understanding. Your lower limit delta isn't even coming into play for as much as I can tell.

Turn off boost control completely and do a 4th gear run at waste gate and show us what happens.

You got lots going on here and you are nowhere NEAR ready to start tuning closed loop advanced mode.

Post your MOST CURRENT TUNE plus a couple recent logs. Please.

 

That is what I thought. EBC duty should be 100% until I am within the Boost Control Lower Limit Delta of my target. In the example above, this means that EBC duty should be at 100% until I hit a MAP of 170kPa. However, what is actually happening is that as soon as I pass 100kPa MAP, EBC duty goes to 60%.

Or do you and DNMakinson mean that it goes to the Max Duty value that I have set and not 100%?

 

Well, you said earlier that you set your max to 60%. So then it will max out at 60.

 

I am not sure what is causing the TPS you are seeing. I pulled TPS into the same datalog and it looks correct (screenshot below with TPS).

Ignore everything I said in post #8. I was misunderstanding how EBC works. I get it now though. I will attach more data logs in the next post.

 

Attached are the following data logs:

2018-05-21_19.22.42_EBC-DC-0,100,10 = Full throttle pulls with EBC Duty Cycle set from 0 to 100 in steps of 10.

2018-05-21_19.31.12_MaxSpoolByTPS-20,100,20_EBCduty100 = EBC Duty cycle is set to 100% for the duration of this data log, with pulls at TPS of 20 to 100 in steps of 20.

Max spool with the wastegate closed can be found in either of those two data logs.

 

Can I see the tune you had with the above logs?

 

Ok, based on your pulls, I did a histogram and interpolated a better bias table.



Try entering this:

 

Ok, load the settings as you see here: (after loading the bias table above)

In the boost control targets, set the target 77% and above at 160kpa, 170kpa, 180kpa, etc... Do a continuous log of each of these, to as high of an RPM as you can safely do so.