Can't seem to tune VVE

[SFM]

Hello All,

I have been taking my time learning and trying to tune my car which is swapped with a stroked LS3 10.5:1 CR, Ported Heads, BTR STG3 NA +400ci camshaft.

Car has been previously tuned but the drivability is crappy and the only good thing in that tune is the power. Decided to tune myself and I just got done with MAF tuning and I did notice a HUGE improvement in drivability, However when I switch to VVE tuning the car wont even Idle even if I tried throttling it a bit. I have tried adding and subtracting 20% on the Vve table but without any progress.

So since I started with this tune OVER the previous tuners file im guessing I may be missing something that causes this issue.

Please do take a look into the tune and let me know if you notice anything different.

my current issues are :

1) cant start tuning VVE
2) surging idle (With AC ON/OFF and car dies if AC was on and coming to a stop)


Thank you.

[kevin87turbot]

Hello All,

I have been taking my time learning and trying to tune my car which is swapped with a stroked LS3 10.5:1 CR, Ported Heads, BTR STG3 NA +400ci camshaft.

Car has been previously tuned but the drivability is crappy and the only good thing in that tune is the power. Decided to tune myself and I just got done with MAF tuning and I did notice a HUGE improvement in drivability, However when I switch to VVE tuning the car wont even Idle even if I tried throttling it a bit. I have tried adding and subtracting 20% on the Vve table but without any progress.

So since I started with this tune OVER the previous tuners file im guessing I may be missing something that causes this issue.

Please do take a look into the tune and let me know if you notice anything different.

my current issues are :

1) cant start tuning VVE
2) surging idle (With AC ON/OFF and car dies if AC was on and coming to a stop)


Thank you.

Oh my. That's a mess.

Here ya go. I loaded stock VVE tables in it for you. It'll be a much better starting point that what you had.
base 2_maf tuning step 1 with lambda on exhaust_MAF DONE 2 STOCK VVE.hpt

[blindsquirrel]

What's the actual, current engine bore & stroke? Because if it's a stroked LS3, the cylinder volume should be bigger than stock 6.2L.

The file you uploaded looks to be set up still for MAF-only, do you have one showing the settings you used for failing the MAF?

[SFM]

What's the actual, current engine bore & stroke? Because if it's a stroked LS3, the cylinder volume should be bigger than stock 6.2L.

The file you uploaded looks to be set up still for MAF-only, do you have one showing the settings you used for failing the MAF?

current Bore & Stroke

Pistons are 4.080
rods are 6.125
Crank is 4.100

thanks

[blindsquirrel]

Then your cylinder volume needs to be 878.42cm3, not 774.99.

[SFM]

So I have been working on tuning the VVE whenever I get the chance and so far the car drives much better but I am still in the process of VVE tuning, Every revision fixes the cells to stoich for about 2%~4% and that is just taking so many revisions.

The process I go through is drive the car for around 30 mins or so and then I copy the cells over to Excel and cleanout the cells with small counts (Filtering out the cells of anything under -2.5 and the cells that have very low counts and then copy them over to VVE table with multiply by half, calculate torque and then proceed to copy/paste to the manifold switch open.

Am I missing any steps or is there any faster steps in doing so? Please take a look at the log and the last tune its just that I haven't yet copied the logged cells over in the last tune attached. And if you can please point me at the right direction of working on fixing the following issues.

1) cold start still needs a lot of work as I have to keep revving the car for about a min or two before is settles and idles fine.

2) during the datalogs I did notice that around 3200 rpms while accelerating there is a slight hiccup on the throttle (Which I think will be gone once I smooth out the zone areas on the VVE table.

3) while idling, turning ON the acc seems to get the idle to swing around 500 rpms Tried messing with the AC ramp out a bit but didn't help.

4) on some of the revisions while datalogging, and while slowly accelerating (to be able to get good cell counts) it feels like something is holding out the car from responding as should. and on other cells it seemed perfectly fine.

5) car is equipped with a Varex electric muffler and the AFR is hooked on the exhaust around 4 inches before that muffler, so lets say i'm on 3k rpm and the exhaust cuttout is open with AFR reading for example 14.1 and at that same RPM when I do close the exhaust cuttout it goes around 1 afr richer which is to 13.1. (should I keep it that way or try to do some changes ? )

6) last but not least, I have tried to work on the idle AFR alone, kept it idling for sometime, then did the changes needed and started the car again, car idles exactly at stoich and everything looks perfect, after the 30 min datalog drive i come to a stock and the idles AFR is a bit richer than what it was. (Is there any fix around this issue ?)


and please do compare the screenshot attached to my last datalog, there were like 4 or 5 revisions in between them but as you can notice that some cells have gone richer than previous tunes even though I made sure that the actual rpm/map cells are not hitting different zones at that certain rpm.


I still think I have a long way to go perfecting the drivability and any shared help is highly appreciated.

ps: couldn't upload the datalog file as it was a drive for about an hour i think, here is the link of tune,datalog & screenshot of the files.

https://drive.google.com/drive/folde...usp=share_link

Thanks.

[gtstorey]

I’ll take a shot at #5.
I guess by AFR you mean your wideband o2 sensor? This needs to be about 16” from open air or as you see it will read leaner than actual. I guess by electric muffler you mean cutouts? If so leave them closed. And hope they are sealing tight.

I would suggest posting much shorter logs. I’m not sure you will get anyone to dig through 1hr log. You may need longer logs to get good data, but post logs that show enough to show it in all conditions or that just show a problem area.

[GHuggins]

Just a couple of comments I'm going to make to hopefully make things a little easier on you. First your MAF curve should be smooth - a little smoother than what you have. Temperature in the intake and combustion chamber will change VE fueling. Just try to do it as cool of an intake air as you can - it'll register richer with heat, but better off to be on the richer side. Inj timing and temperature settings/corrections for the VE table will bring things in tighter, but you'll always have some swing.

Next - why not make this easier? There are some good maths out there that will allow you to back calculate the VE table based off of airflow. Leave the MAF in the equation setup to run primarily off of it and make corrections that way... Here's two.

This one uses temperature and airmass to calculate the VE table - entirely depends on how you work the pedal on how close it'll get things...
(([50041.223]*(273.15+[50011.241]) * (1000/[50030.91]))

This one uses MAF with fuel trim correction to make VE the same airflow as your MAF... You can modify it to further use lambda as the correction factor. You'll paste special multiply by percent or half percent with this one.
100 * ((([50040.71] * ([50114.156] + [50116.156])) - [2311.71]) / [50040.71]

Now of course you have to log the channels in the math formulas for them to work. Your goal is to have dynamic, VE and MAF all agree with one another, so why not work with that?

The MAF one relies on fuel corrections via trims being close to a lambda of 1 - in other words if I'm adding 30% fuel via fuel trims the wideband needs to show something close to a lambda of 1.

[SFM]

I’ll take a shot at #5.
I guess by AFR you mean your wideband o2 sensor? This needs to be about 16” from open air or as you see it will read leaner than actual. I guess by electric muffler you mean cutouts? If so leave them closed. And hope they are sealing tight.

I would suggest posting much shorter logs. I’m not sure you will get anyone to dig through 1hr log. You may need longer logs to get good data, but post logs that show enough to show it in all conditions or that just show a problem area.

Yes, I was referring to the WB as the AFR, Couldn't hook it up after the (Electric muffler - https://xforceusa.com/products/vmk11-350/ ) as there is no proper space to fix the lambda sensor. I also had the lambda snsor hooked on the exhaust tip before starting everything and the reading was all over the place for some reason which I assume being the 19.5* overlap cam.

Also leaving the cutouts closed never helps in datalogs especially when keeping the rpm hanging for some time for proper data.

I apologize for the long log, I went for a drive on the highway and just kept collecting whatever cells I could. I will be taking another log tonight and a shorter one for sure.

[gtstorey]

The wide band is typically hooked up close to the engine in the area that the stock front o2 sensors are located. I'm having trouble picturing your set up.

[SFM]

Just a couple of comments I'm going to make to hopefully make things a little easier on you. First your MAF curve should be smooth - a little smoother than what you have. Temperature in the intake and combustion chamber will change VE fueling. Just try to do it as cool of an intake air as you can - it'll register richer with heat, but better off to be on the richer side. Inj timing and temperature settings/corrections for the VE table will bring things in tighter, but you'll always have some swing.

Next - why not make this easier? There are some good maths out there that will allow you to back calculate the VE table based off of airflow. Leave the MAF in the equation setup to run primarily off of it and make corrections that way... Here's two.

This one uses temperature and airmass to calculate the VE table - entirely depends on how you work the pedal on how close it'll get things...
(([50041.223]*(273.15+[50011.241]) * (1000/[50030.91]))

This one uses MAF with fuel trim correction to make VE the same airflow as your MAF... You can modify it to further use lambda as the correction factor. You'll paste special multiply by percent or half percent with this one.
100 * ((([50040.71] * ([50114.156] + [50116.156])) - [2311.71]) / [50040.71]

Now of course you have to log the channels in the math formulas for them to work. Your goal is to have dynamic, VE and MAF all agree with one another, so why not work with that?

The MAF one relies on fuel corrections via trims being close to a lambda of 1 - in other words if I'm adding 30% fuel via fuel trims the wideband needs to show something close to a lambda of 1.

during the MAF curve tuning, specifically when I hang the the rpm for some time, the Lambda just jumps full lean mode and skews the written data and would not go back to normal unless I floored it for a second, and doing that messed up my time of datalogging. So I did what I could into getting it close to stoich and was planning to come back to fine tuning the MAF after im done with VVE.

I did what I could to keep the temps down. ( I did have issues with the engine bay heat soaking with temps over 167F ) so after a couple of fixes and managing to get more air flowing I was able to get the temps down and it is almost around 40f higher than the current weather. still planning to lower the temps but needs a lot of work so i guess this does it for now. and now before taking any logs I just drive around a bit to make sure I got rid of all the extra engine bay heat.

I'll be more than happy to try out the methods you mentioned with the formulas above, If you have any article or a post helping me out setup those math formulas I'll be more than thankful.


Will try to set them up on my own as well hoping they work out and will let you know with what I come up.

thank you.

[blindsquirrel]

If the wideband is located too close to fresh air it'll be useless at anything but WOT, if it even reads right then.

[SFM]

I finally decided to give the MAF + VVE a try and would like to get your opinions if I did the maths correct or may have missed something, I know the log should be at steady state throttle but I just thought I'd give it a try and see how it turns out and to make things easier as vve Alone took over 20 revisions to get me anywhere from 14% lean down to almost 4% using paste special > multiply by half. there were some spots that really got me frustrated as the changes I made barely made any difference on those certain cell spots.

------------------------------------------------------------------------------------------------------------------

GMVE_CL Maths : (STFT enabled / LTFT Dissabled )

(([16.71.avg(200)]*(1+(.01*[6.156.avg(200)]+.01*[8.156.avg(200)])/2)-[12.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)])/([12.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)]))*100

Closed loop Filter used : [2517.161.avg(1500)]=0 and [2517.161.avg(-200)]=0 and (abs([50090.156.slope(1500)])+abs([50090.156.slope(-500)]))<2 and ([6310]=9 OR [6310]=14 OR [6310]=15)=0

------------------------------------------------------------------------------------------------------------------

GMVE_PE maths : (Single wideband)

(([16.71.avg(200)]*((1+([50127.238.avg(200)]-[50118.238.avg(200)])/[50118.238.avg(200)])+(1+([50127.238.avg(200)]-[50118.238.avg(200)])/[50118.238.avg(200)]))/2-[12.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)])/([12.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)]))*100

PE Filter used: [2517.161.avg(200)]=0 and [2517.161.avg(-200)]=0 and (abs([50090.156.slope(250)])+abs([50090.156.slope(-250)]))<2 and [6310.avg(250)]=9

-------------------------------------------------------------------------------------------------------------------

Maths created using Smokeshows excel cheat sheet over this post.

https://forum.hptuners.com/showthrea...ight=smokeshow


if you can see in the logs now that I set up the GMVE_CL (on narrow bands) & GMVE_PE (external wideband) no should I copy the CL or the PE ? they both look different and as for the MAF I am not using any filters as I did not know which to use or what to put in the formula and for some reason it is a bit leaner than what I last saw when I was tuning the MAF.


Maf flow / VE Airflow / Dynamic Airflow are kind of close but would like to get them on point if somepne could please point me in the right direction.

Notice also How I had to spread few MAP zones in order to get the best possible reading. ( is that Okay ? )

thanks

[Cringer]

I finally decided to give the MAF + VVE a try and would like to get your opinions if I did the maths correct or may have missed something, I know the log should be at steady state throttle but I just thought I'd give it a try and see how it turns out and to make things easier as vve Alone took over 20 revisions to get me anywhere from 14% lean down to almost 4% using paste special > multiply by half. there were some spots that really got me frustrated as the changes I made barely made any difference on those certain cell spots.

------------------------------------------------------------------------------------------------------------------

GMVE_CL Maths : (STFT enabled / LTFT Dissabled )

(([16.71.avg(200)]*(1+(.01*[6.156.avg(200)]+.01*[8.156.avg(200)])/2)-[12.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)])/([12.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)]))*100

Closed loop Filter used : [2517.161.avg(1500)]=0 and [2517.161.avg(-200)]=0 and (abs([50090.156.slope(1500)])+abs([50090.156.slope(-500)]))<2 and ([6310]=9 OR [6310]=14 OR [6310]=15)=0

------------------------------------------------------------------------------------------------------------------

GMVE_PE maths : (Single wideband)

(([16.71.avg(200)]*((1+([50127.238.avg(200)]-[50118.238.avg(200)])/[50118.238.avg(200)])+(1+([50127.238.avg(200)]-[50118.238.avg(200)])/[50118.238.avg(200)]))/2-[12.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)])/([12.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)]))*100

PE Filter used: [2517.161.avg(200)]=0 and [2517.161.avg(-200)]=0 and (abs([50090.156.slope(250)])+abs([50090.156.slope(-250)]))<2 and [6310.avg(250)]=9

-------------------------------------------------------------------------------------------------------------------

Maths created using Smokeshows excel cheat sheet over this post.

https://forum.hptuners.com/showthrea...ight=smokeshow


if you can see in the logs now that I set up the GMVE_CL (on narrow bands) & GMVE_PE (external wideband) no should I copy the CL or the PE ? they both look different and as for the MAF I am not using any filters as I did not know which to use or what to put in the formula and for some reason it is a bit leaner than what I last saw when I was tuning the MAF.


Maf flow / VE Airflow / Dynamic Airflow are kind of close but would like to get them on point if somepne could please point me in the right direction.

Notice also How I had to spread few MAP zones in order to get the best possible reading. ( is that Okay ? )

thanks

This should help, let me know.
base 2_VE_Tuning_40_MAF On - Cringer.hpt

[SFM]

This should help, let me know.
base 2_VE_Tuning_40_MAF On - Cringer.hpt

Appreciate the fix, If you don't mind letting me know based on what were the changes made ?

I noticed that MAF,VVE, Idle rpm, airflow minimum, oxygen sensor > (Mode vs. Airflow) had changes made in them.

Because I have tried copying the MAF log multiply by half or just multiply and that did not reach your changes.
VVE looked smoother in the 3D graph yet I don't know which did you copy.. EQ ERR, GMVE_CL or GMVE_PE ?

and those Airflow changes ? based on ?

trying to get things clearer so I can make my changes with the right steps instead of the all the trying and guessing.

Thank you.

[Cringer]

Appreciate the fix, If you don't mind letting me know based on what were the changes made ?

I noticed that MAF,VVE, Idle rpm, airflow minimum, oxygen sensor > (Mode vs. Airflow) had changes made in them.

Because I have tried copying the MAF log multiply by half or just multiply and that did not reach your changes.
VVE looked smoother in the 3D graph yet I don't know which did you copy.. EQ ERR, GMVE_CL or GMVE_PE ?

and those Airflow changes ? based on ?

trying to get things clearer so I can make my changes with the right steps instead of the all the trying and guessing.

Thank you.

Its a lot to explain, but this is all based on my experience with my surging cam issues...which is the reason why I even bought HP Tuners in the first place. I won't go into detail with the changes I made because that would be a super long post.

I used to go with the GMVE_CL and GMVE_PE, but I don't do that anymore. Getting VVE settled at low RPM is going to help a lot. With a cam that big, at idle, there is going to be too much reversion to rely on the MAF, so VVE is key. In the end, the VVE is always a balance of smoothness and accuracy. So use the numbers to get it into the rough shape it wants, then blend and smooth by hand for each zone and the transition to/from each zone to the next. It is going to be hard to dial in VVE on a 17 minute log though. I would suggest driving around for at least an hour and getting as much variability in throttle position, RPM, and gears 1-6. Also, sit and let it idle for 2-3 minutes too.

The airflow min is probably going to help the most here IMHO. As the RPM's drop, the previous tune was trying to slam in more air. Combined with the overall shape and erratic VVE curve, it was causing a lot of air and fuel. And to make matters worse, the idle spark was 25*. When the spark is that high, there is not a lot of reserve torque left to help raise the RPM when it needs it. At idle (when the RPMs drop), there is a huge difference between advancing timing from 12* to 15*...but there is NOT a lot of difference between 25* to 30*.

I also changed [ECM] 12466 to shift the zones down into your idle area to help prevent wild fuel oscillations from the proportional gain (based on what I see with your wide band).

So really, this is just trying to tone down extreme changes in fuel and air, as well as reducing the timing to give room for better idle control torque.


Here are some videos I made that should help:

• Here is a video I made regarding MAF (and VVE airflow): https://youtu.be/xRZaTblSQ_0
• Here is a video I made about a program I wrote to help tackle VVE tuning: https://youtu.be/_Eiyy460C_k

Future suggestions:

• You are most likely going to have to re-zone the VVE boundaries to make the transitions smoother as you get closer to the final shape. (tables [ECM] 3066 and [ECM] 12172)
• You are going to need to add more channels in your log.Cringer.Channels.xml
• You may still need to address the adaptive idle section as well as the throttle follower