HOW TO: Setting up Fuel Trim Graph in VCM Scanner V3 on Virtual VE Vehicles

[ctsvnut]

ok im doing something wrong, I tuned the car into running like shit, lol and went back to where I started before messing with the VVE tables and its much better. It was idling bad with large hesitiations and my trims were not getting any smaller.

making the MAF fail made it even worse.

should I be doing the multiply by % - half maybe??

[steve-0]

Paste special, multiply by % (or half)

If you got a value of +2% that means increase that cell of VE/MAF tables by 2%, same as fuel trim values work.

-2% would mean decrease it by 2%

do i have to disable MAF ?

[5FDP]

If you want to tune just the VVE, then yes you do.

If you want to tune mainly the MAF, then set the dynamic airflow setting much lower at like 200rpm, then switch it back when you are done with both to have the best of both.

[DCM1]

i have on the row axis map/baro (pressure ratio) on vve table instead of mainifold absolute pressure (kpa) on 2017 chevy silverado what do i do to make it match graph in hptuner scanner

[schpenxel]

Uh, use pressure ratio instead..?

[obd2]

i have on the row axis map/baro (pressure ratio) on vve table instead of mainifold absolute pressure (kpa) on 2017 chevy silverado what do i do to make it match graph in hptuner scanner

have the same issues too with ctsv lt4. map/baro (pressure ratio. has anyone found the right one to pick. tried pressure ratio to no avail

[schpenxel]

Post a log, tune and your current layout and I'll fix it

The most common problem is people not logging barometric pressure. Have to have that to calculate pressure ratio.

[8850]

Haven't read though all the replies in this link but does this configuration look correct?

Also what my log looks like and the log. Not quite like shepenxel's.

[8850]

I think my problem I can't get the row in my file to match the example in reply 17. I have Map/Baro (pressure ratio) in the row in my file but not finding Manifold Absolute Pressure as per instructions.

[schpenxel]

If you can post your layout I can show you what it should look like but what you posted is just a channels list which I can't really do anything with

And the current tune wouldn't hurt either.

[8850]

If you can post your layout I can show you what it should look like but what you posted is just a channels list which I can't really do anything with

And the current tune wouldn't hurt either.

Here's my layout.

[schpenxel]

All you have to do is change row axis (that you currently have set to MAP) to pressure ratio... that's it. It just needs to match your tune (which is pressure ratio on gen 5 ECM's). I also adjusted the colors to ones that work better for me. Attached is the updated one

Variable VE layout.Layout.xml

PR.JPG

[8850]

Thank you schpenxel!

[schpenxel]

If you're not going to be running boost then I'd change the pressure ratio axis in virtual VVE editor to just go up to 1.0, then make Scanner the same.. you'll get more resolution in places you'll actually use vs. how it is now. Just click on the label of the pressure ratio axis and change it in VVE editor

[8850]

If you're not going to be running boost then I'd change the pressure ratio axis in virtual VVE editor to just go up to 1.0, then make Scanner the same.. you'll get more resolution in places you'll actually use vs. how it is now. Just click on the label of the pressure ratio axis and change it in VVE editor

Good point. Although it is boosted I will only be checking my VVE table up to about 3000-4000 rpm and no WOT. Above that I will be going into PE.

[8850]

Maybe something like this? I limited the rpm too 4500 also.

[schpenxel]

Give it a go and see how it works

I didn't know you were going to be running boost.. if that's the case I'd still try to get the rest of the VVE table to be in the right ballpark.. it's still referenced somewhat even in MAF only, especially for quick changes (transients) so it's not a bad idea to have it close

[8850]

Will do. Another good point. Thanks for all your help schpenxel!

[mightyquickz28]

Thanks for this! I'm just starting to tune a friends Turbo 416 cubed 2011 Camaro. I'm done fine with my own Gen III E85 tuned 3 bar SD Turbo 5.3 (96 Z28, Transbraked TH350) but I've seen that the E38 computer of Steves car is quite different from my 0411 and I was wondering how to setup his graph for attenuating his MAF. His still has the stock MAF settings even with the bigger cubes, aggressive cam, large heads and Turbo. I scanned it and read the logs and could see swings of...
Bank One:
LTFT = -5.47 to 6.25
STFT = -15.63 to 14.84

Bank Two:
LTFT = -4.69 to 2.34
STFT = -14.84 to 14.06

[schpenxel]

This is pretty basic

All graphs only really have 3 things you have to know

1. What do you want on the column axis? i.e. What is the column axis on the table you're trying to tune?
2. What do you want on the row axis? i.e. What is the row axis on the table you're trying to tune?
3. What is the parameter you're wanting to see reported? What are you using to tune whatever you're tuning? i.e. fuel trims, EQ Ratio error, etc.

Answer those few things and your graph is basically done

For MAF tuning:

1. Column axis parameter = mass airflow FREQUENCY. That's the column axis on your MAF table
2. Row axis parameter = LEAVE BLANK, there is no row axis in the MAF table
3. Parameter you want is fuel trims. V3.6 has a built in math parameter called LTFT + STFT which, as the name would suggest, adds together LT and ST fuel trims to give you a total. I usually use that one for part throttle tuning

Obviously you'll need a wideband for WOT tuning.