HOW TO - Control boost using ECUFLash and 3 port GM boost solenoid

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Oct 23, 2018, 08:19 PM

#556

Raptord

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You can log Boost Error in Evoscan, then add a column to the log in Excel afterwards where you would subtract Boost Error from the logged boost. That should give you an idea of what the ECU is (or think it is) targeting. Note that I think Boost Error only has a +/- 3psi range if I remember correctly, so you'll have to be in the right ballpark for it to work. However if boost error stays pinned at -3 the whole time for example, then you'd know the ECU is targeting a higher boost, so you can adjust the desired boost tables to eventually reach the right number.

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Oct 24, 2018, 07:32 AM

#557

MR Turco

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Quote:

Originally Posted by Raptord

Understood and logging that. Hoping i can narrow down why there is a delta. That is how i'm working around it but i would like to be more precise or understand what is influencing the discrepancy.

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Oct 28, 2018, 01:44 PM

#558

Evo_Jay

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Quote:

Originally Posted by MR Turco

So a couple of oddities i haven't seen before. I've only deeply tuned this on a 9 but working to get this setup on a buddy's car (05 8) using PSI controlled boost on 9653 V7 rom w/ OMNI 4 bar and stock maf.

On the Boost desired PSI table - minimum value is 7.4. Not an issue but it's odd.
I am targeting 30psi but i notice i am getting boost error correction at <30 PSI - starting around 2-3psi lower than expected - AEM boost gauge is showing under target PSIa as well.
- Can't tell if logs aren't granular enough or if the ecu is attempting a different target
- Is there a way to log what my boost target is - what the ECU thinks it is

I ended up turning off all downward correction including IAT just to get a boost curve set. But trying to understand the discrepancy since I would like to enable error correction. I can workaround most of this I just dont recall seeing this years ago when i tuned this, it was very on par.

Thoughts?

Thanks in advance
-Mike

Check the map sensor settings for the boost control tables. Thats most likely your issue.