GMVE Help

[Dave_In_VA]

If anyone is struggling with the formula(s) here is a cheat sheet to put it together for you.

Edit:
5 Nov 2021, version 2 sheet attached. If you've successfully used revision 1 there is no change to the formulas it spits out. Just made it easier for guys who hate long math parameters to get up and running.

I found Hjtrbo's spreadsheet (Very Cool...) to create the GMVE parameter. I created the correct parameter.

The full math is: (([16.71.avg(200)]*(1+([50119.238.avg(200)]-[68.238.avg(200)])/[68.238.avg(200)])-[50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)])/([50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)]))*100

Then I attempted to create a graph. I used my VE AFR % Error graph as a model.

I got GMVE Error created, but I don't see the option to set units to percent.

Anybody got any ideas?

[GHuggins]

This is what I use. Keeps fueling errors out of the picture (90some percent anyway). It's been checked and after a few passes can get within 2 to 5% errors. Just make sure to get some good 30 or so minute driving around logging. I had a really fancy equation years ago that used afr or lambda error, but it was constantly anywhere from 2 to 15% off, so I stopped using fueling as it rely's on being in open loop and a near perfect MAF curve that won't ever exist because of multipliers and offsets, so....

(([50041.223]*(273.15+[50011.241]) * (1000/[50030.91]))

[hjtrbo]

@Dave_In_VA
This is how mine is set, see if it works for you.

Capture.JPGCapture1.JPG


@GHuggins
I always like the new things you pass on. Looking at the screen shot of the (shamelessly cherry picked of course) run pictured below, I have all the 3 airflows lining up (MAF, DYN, VE) with EQ error +/-1%. If I plot the VE Airflow against the calculated VE I have a small discrepancy. How would I bring all those together?

Capture3.JPG

[GHuggins]

You've got it that good then there's no point in getting them identical That's honestly the best I've seen any especially with the way fueling can change. Not even an OE calibration has them that close

[Dave_In_VA]

@Dave_In_VA
This is how mine is set, see if it works for you.

Capture.JPGCapture1.JPG

@hjtrbo - Many thanks. I hadn't selected Percent in the Math Parameter setup. Thank you for the picture. Hopefully all works well now.


So If I understand this concept properly, I keep the car in MAF mode and adjust VE table values based on the GMVE error percentages. Is this correct?

Also, I assume that after a tune drive, I should only change either MAF or VE, not both. It seems better to change one variable at a time.

[hjtrbo]

Nope, keep car in normal blended air flow mode. I.e. maf and dynamic enabled like stock. A good filter and pillow like throttle transitions is key to good results.

Smokeshows and GHuggins formulas will work. In any case make sure that any channel involved with those formulas is polled at least 20Hz.

[midTnMike41]

Nope, keep car in normal blended air flow mode. I.e. maf and dynamic enabled like stock. A good filter and pillow like throttle transitions is key to good results.

Smokeshows and GHuggins formulas will work. In any case make sure that any channel involved with those formulas is polled at least 20Hz.

Can you share the filters you are using for GMVE and MAF for open and closed loop?

In the spreadsheet the filters reference [2517.161], what is that? On my gen4 its coming up as Torque Mgt Advance. Is that correct?

[hjtrbo]

Haven't got them handy but if look a few pages back in the simultaneous gmve thread I've posted them there.

Yes. Filters out the shift in an auto. If manual you'd need to adjust the filter to suit.

[Dave_In_VA]

So, I'm making progress in both my tune and my attempt to use the GMVE method.

In the attached pic, My GMVE error, which I believe should be a percentage is in the 30K to 50K range, whole numbers. I'm obviously doing something wrong. :-(

Pics of my graph layout and EQ Ratio and GMVE math parameters are attached. In the Scanner GMVE View pic the GMVE value is 50,919.


The formula in my math parameter is: (([16.71.avg(200)]*(1+([50119.238.avg(200)]-[68.238.avg(200)])/[68.238.avg(200)])-[50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)])/([50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)]))*100

In the examples in this thread, instead of 50119 the value is 36. I think I am using the correct value. My 50119 is EQ Ratio Sensor and the unit is Lambda, the same for 36 used in @hjtrbo's pic.

My GMVE Error MathParameter.XML file is also attached.

Anybody got any ideas what I am doing wrong?

Thanks, Dave

[Leva]

Are you sure you copied your column and row axis correctly unto the graph? Im using an 08 Vette tune and column is RPM and row axis is MAP. Maybe the VE table was the opposite in 05. Also you need to click percent % as the unit in the graph and 1 for decimals.

And the channels you are logging should match the math's units. MAF should be logging in g/s, MAT in K etc.

[blindsquirrel]

Are you sure you copied your column and row axis correctly unto the graph? Im using an 08 Vette tune and column is RPM and row axis is MAP. Maybe the VE table was the opposite in 05.

E40 is the odd duck with the axes flipped from everything else.

[eXo3901]

In the attached pic, My GMVE error, which I believe should be a percentage is in the 30K to 50K range, whole numbers. I'm obviously doing something wrong. :-(

Pics of my graph layout and EQ Ratio and GMVE math parameters are attached. In the Scanner GMVE View pic the GMVE value is 50,919.


The formula in my math parameter is: (([16.71.avg(200)]*(1+([50119.238.avg(200)]-[68.238.avg(200)])/[68.238.avg(200)])-[50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)])/([50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)]/[2126.240.avg(200)]))*100

In the examples in this thread, instead of 50119 the value is 36. I think I am using the correct value. My 50119 is EQ Ratio Sensor and the unit is Lambda, the same for 36 used in @hjtrbo's pic.

Parentheses matter and 50119 reports something like 500-600 lambda in the channels at idle. You need to apply the correct math conversion/transform to this PID/Channel in the user math as well. Enter the correct conversion to 1 lambda for your sensor within the bold parentheses below.

((([16.71.avg(200)]*(1+((([50119.238.avg(200)])-[68.238.avg(200)])/[68.238.avg(200)])))-(([50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)])/[2126.240.avg(200)]))/(([50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)])/[2126.240.avg(200)]))*100

[Dave_In_VA]

Gotta love HPT. Now it isn't seeing my wideband. Some channels don't show at all.

Again thanks to @eXo3901...

[hjtrbo]

Lol, yep. Try repolling parameters from one of the scanner menus.

[Dave_In_VA]

Parentheses matter and 50119 reports something like 500-600 lambda in the channels at idle. You need to apply the correct math conversion/transform to this PID/Channel in the user math as well. Enter the correct conversion to 1 lambda for your sensor within the bold parentheses below.

((([16.71.avg(200)]*(1+((([50119.238.avg(200)])-[68.238.avg(200)])/[68.238.avg(200)])))-(([50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)])/[2126.240.avg(200)]))/(([50070.56.avg(200)]/60*4*[11.92.avg(200)]*[2312.avg(200)])/[2126.240.avg(200)]))*100

So, in this part of the formula highlighted by @eXo3901: ([50119.238.avg(200)])

I need to enter the correct conversion to 1 lambda for my sensor. To do this, I believe I transform it the same way I transform the LM2 input to get my AFR (I Think ???).

If my hypothesis is correct then per the attached pic, the new formulae would be:


(([50119.238.avg(200)]/68.05)+7.36)


Am I smoking something green, or could I be on the correct path???

Again, thanks to @eXo3901, @bjtrbo, @blindsquirrel and all others for helping...

Dave

[Dave_In_VA]

If my hypothesis is correct then per the attached pic, the new formulae would be:

(([50119.238.avg(200)]/68.05)+7.36)

This is what I use as a math parameter to convert my EQ ratio to AFR. That's not lambda. And, it didn't work.

I also tried: (1/[50119.238.avg(200)]) this didn't seem to work either.

So, how do I convert the following to lambda?

([50119.238.avg(200)])

I've tried anything I can think of and everything I found in a post. All to no avail.

Could this be on the right track: https://forum.hptuners.com/showthrea...l=1#post563085

[hjtrbo]

Nothing you do to the math parameter will work until you get the wideband reading right in the channels list first.. Based on the AFR reading at the top of the channels list that lambda reading should be around 1.00 not 509!
Capture.PNG

[Dave_In_VA]

Nothing you do to the math parameter will work until you get the wideband reading right in the channels list first.. Based on the AFR reading at the top of the channels list that lambda reading should be around 1.00 not 509!
Capture.PNG

Well Damn.... Another thing to figure out

In looking at the owners manual (see attached pic). This could be a simple change.


However, I'll also betting that once Lambda is being output my other variables and maths will change as well.

[Dave_In_VA]

In looking at the owners manual (see attached pic). This could be a simple change.

Ok, I connected and my LM-2 is already outputting lambda.

2022-04-28 (1).png


Then I guess its my math that is converting lambda to the fluxuating 500 figure

[smokeshow]

Ok, I connected and my LM-2 is already outputting lambda.

2022-04-28 (1).png


Then I guess its my math that is converting lambda to the fluxuating 500 figure

I sent you a message saying exactly that

Even if the calculation looks realistic, everyone should be checking all inputs to see if they make sense. In the case of a wideband, leave it in open air and see if the reading with key on engine off generates the maximum value that the manufacturer says it should. Fat fingering can cause issues that aren't as easily noticeable as a lambda value of 500.