Boost Control not working
 

Hi,

Just finished installation of a GT2554r onto a 1.8 with begi cast mani, begi downpipe into a 3" exhaust and ms3x. I'm looking for some help to get my boost control working correctly. I have the DIYAUTOTUNE boost controller connected and was targeting about 5lbs of boost to get me started. I set the overboost protection to about 12lbs. Overboost seems to be working, in the attached 3rd gear run i didn't get into protection, but I ended up with over 10psi of boost so something isn't right with my controller....hoping somebody smart might know what I did wrong with my settings or next things to test. I did try the controller on normal and inverted but that didn't appear to make a difference..Thanks in advance

https://www.miataturbo.net/attachmen...ine=1425958673

https://www.miataturbo.net/attachmen...ine=1425958673

I would guess that your wastegate is set at 10psi, and you can't use boost control to make less boost than wastegate pressure. Do a log without EBC and see what boost you end up at. You can't go any lower than that with EBC.

Wastegate is set to around 6 psi if I plumb it directly

Whats your open loop map look like?

Just for reference this is what it looks like bypassing the EBC, plumbing straight to the wastegate - 6.6psi max.

https://www.miataturbo.net/attachmen...ine=1425986764

To be honest I went straight to working with closed loop - do I need to go back a step or two ?

spark cut. lol.

Last TS version I tuned closed loop used the open loop table as a base lookup table.

Yup ! lots of it too, I don't seem to have any issues getting lotsa boost...problem is controlling it....

Would you recommend Spark and fuel ? - Never done this b4, I need wisdom...

No, there is a different table for that.

either fuel only or fuel/spark. never spark only.

what does your closed loop boost targets table look like? have you tuned it? what about your intial values table?
and have you tuned the closed-loop senestivity at all?

except it appears that's how he's configured his boost control to work.

Done, thanks !


You are giving me way to much credit - I'm not really sure what the optimal way to configure this is - is there a better way ? I'm open to suggestions.

Initial map table is all set to 100, but I just turned that on and had the same problem running with it off.

Closed boost table is basically 135 in all cells except at 0 throttle, I have not tuned it, i was just looking to see when/if it worked.

I haven't played much with the closed loop sensitivity much yet either - I moved it from the middle of the bar to full and then back to about 3/4's that all so far....

135psi = what 5psi?

how is that going to work? :P


set the closed loop targets table up to what you actually wanna hit. so like 170kpa, then try again.

Ok, will do, thanks, I was perhaps being too conservative.... How should I handle the initial boost table, not totally sure what this does relative to the closed loop table ?

You have quite a bit more searching to do. There are some good how-tos about setting up EBC on this forum and on msextra. I can link you the ones I used when I get home but someone else will chime in too.

I would go open loop and figure out what you need to run at around 9psi. Once that is done, transfer those values to your initial values in closed loop and your closed loop target to the values you want as stated above. My open loop values at around 4000 to 4500 rpm have to be set very low on boost duty or it will spike well past my intended value. The lower values in closed loop kept it from spiking there as well.

Update
 

Thanks for all the help. I managed to confirm it all works in open loop, and am now starting to play with the closed loop settings. I'm following Mr Brianeak"s guide here

here's how I tune CL EBC.

1. Make sure the solenoid is hooked it up and properly configured. This means selecting the correct output pin, freq. (39Hz for DIY solenoid), polarity, etc.
2. Populate CL targets
3. Set PID to 100 0 0
4. Log, do a quick pull to spool up the turbo.
5. If CL targets are not reached, then lower P, repeat #4. (will probably need to go to ~15 0 0)
6. Once PID CL EBC is hitting your CL target lower it slightly so it peaks over it 1-2psi, log and do redline pulls.
7. Increase I until your target is maintained through the revs. Increasing I will lower the sensitivity to P, so P must be added back in as I is increased.
8. Add D to smooth out the boost plot. Increase I and P where necessary.

Through step 5 all is well - my P = 13 doing 2nd gear pulls, 14 would take me just over my target. Now I'm starting to play with I, It seems to be great in 2nd gear but 3rd or 4th I get into a overtarget situation again.

Ran out of time last night but I assume I keep in tweaking up I (an P) until 3rd and 4th gear behave, and I'm reaching my boost target reliably...

I currently have a totally flat boost table - basically 176kpa at all throttle openings and rpm's - I don't totally understand the principals of what to setup here - I don't see why i wouldn't want max boost at all rpms and speeds - can somebody please enlighten me on the principals for setting up the boost target table ? Thanks

that guide is old, and i suggest not plugging in the PID and just using the sensitivity slider.

I wrote that before they made a lot of improvements to the CL PID code.


You'll want to start limiting boost by TPS%. you'll see when you're on the highway and you're hitting 12psi at 5% throttle on a small incline.

That a good help to start with, thanks - I have tried searching but I can't really find any good info on setting this table up, most posts seem to be about getting EBC to work properly....

Making progress
 

OK, Making progress - I think....Tuning with the slider I seem to be way left - down to 26 in order to get a run without oscillation. Here are my settings and boost table now..

https://www.miataturbo.net/attachmen...ine=1426899874

And here is the resultant Boost im getting

https://www.miataturbo.net/attachmen...ine=1426899874

I appear to be a little low to my boost target - max I'm seeing is 10.5psi with a target of 12...any thoughts ?