Transient/Tip-In help wanted

[TJ Folse]

Ive been having some trouble figuring out what I need to adjust and how much to get my Transient fueling to look a little better.

Ive done MAF calibration and gotten it fairly close, so my issue seems to be isolated mostly to Tip-in and exaggerated by being in low rpm, as if i roll onto the throttle nice and slow my AFR follows commanded decently.

Ive tried adjusting the VVE table but it seems to undo most of my changes when I click "calculate coefficients". Ive also tried adjusting table "13624 Impact Factor Gas" but im not seeing any significant changes.

Attached are a couple of events i could find and isolate for an example, as well as the full log and current tune. If there is any more information that would be helpful, or a particular scenario/channel you'd like to see logged, please let me know.



2014 Camaro
Texas speed LS3
Magnusson TVS2300 Heartbeat
Texas speed stage 3 SC cam
PRC CNC heads
LT headers

[hjtrbo]

others have more experience, but just for a test try and run back to back identical scenarios where the 2nd run has the manifold volume +20%.

[07GTS]

the VVE will be alot of it when ur blended so that will have to be right, it has to calculate out so u can adjust the boundary's so its more even for your working rpm/load areas then it should calculate out closer to your changes

[eXo3901]

MAP sensor offset looks incorrect. What MAP sensor (the part #) are you using? Offset should probably be -11.25 for the GM 3bar.
What injectors? Was the injector data input correctly??

[TJ Folse]

07GTS,

Is it normal for the changes i make to the VVE to be somewhat "reverted" upon calculating coefficients? at one point i tried making a dramatic change (like 30 or 40% change) just to know if i was adjusting the correct table and when it calculated coefficients the values end up nearly unaffected...

[hjtrbo]

That's how it works. The coefficients are generated based on a best fit algorithm. You can't just paste special multiply % and walk away. You have to blend those changes in. Then you will find the coefficients work better for you. Also as 07gts said, if you find a shitty area that after blending you still can't get right, then adjust zone boundaries like he said.

[hjtrbo]

And also please double check as per eXo3901s post.

[pannetron]

If you haven't already adjusted the enrichment rate, try this: enrichment_rate.jpg

[TJ Folse]

That's how it works. The coefficients are generated based on a best fit algorithm. You can't just paste special multiply % and walk away. You have to blend those changes in. Then you will find the coefficients work better for you. Also as 07gts said, if you find a shitty area that after blending you still can't get right, then adjust zone boundaries like he said.

OK, i knew that the changes had to be blended in, just wasnt sure how aggressive i needed to be with my changes.

[TJ Folse]

the VVE will be alot of it when ur blended so that will have to be right, it has to calculate out so u can adjust the boundary's so its more even for your working rpm/load areas then it should calculate out closer to your changes

By "changing the boundary" are your referring to the max kpa/rpm in the vve table? like changing them so that it doesnt read off the table when it goes into boost? if so i've done that. or do you mean changing the numbered zones?

[07GTS]

changing the actual boundary zones, ive noticed that if u change the axis so u suit what boost and rpm u will see or even little over, then look at the zone numbers and adjust the boundary's rpm/map so they are more even throughout the whole table, seems after changes when u calculate it can help it stay smoother, it dosnt have to be perfect tho as its not an actual VE so the calcs will work

[TJ Folse]

changing the actual boundary zones, ive noticed that if u change the axis so u suit what boost and rpm u will see or even little over, then look at the zone numbers and adjust the boundary's rpm/map so they are more even throughout the whole table, seems after changes when u calculate it can help it stay smoother, it dosnt have to be perfect tho as its not an actual VE so the calcs will work

Ok, so I made some changes, but even with about a 30% change in values after calculating coefficients, i see no/little change in the logs, attached is an example. you can see that at low rpm, after going into boost a bit, the car just leans out.. the left is before the changes, and right is after the 30% change in the vve table. I've got to be doing something wrong.

[pannetron]

I chased this for a long time in my tune. Since I have a good MAF location, my final workaround was to lower the dynamic airflow settings. This works well for me, your mileage may vary!

2022-08-18_08-22-26.jpg

[07GTS]

if ur running blended always log the maf g/s ve g/s and dynamic aiflow g/s and put them together in the chart v time they should almost follow each other, if u see a lean or rich spot look at the dynamic and then see which other is the same as it, during throttle movements it will bias to ve and after a few sec of steady it will go back to maf

[GHuggins]

VE going into boost is your problem - if you have to copy out of a ctsv and go from there. It keeps reverting it because of the factory dips in the boost areas. Click on the axis on the left and change to a 2 bar view once you have the VVE tables open - also might want to make the open and closed tables the same - those ridiculously high values in the closed table may be throwing the os's comprehension for a loop when it's referencing the open table - never know....