General Motors Volumetric Efficiency.
General Motors Volumetric Efficiency.
Thank you!Originally Posted by eXo3901
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.
Last edited by hjtrbo; 11-05-2021 at 04:59 AM. Reason: Revision 2
Nice! Great cheat sheet.
This is for the E38 correct? My issue is trying to convert these to values for an E67. There are a few choices in the E67 for these different values that I don't know which will work. Trial and error on my part I suppose. If I figure it out, I will post my formula here for the E67 guys wanting to try this.
Thank you for the chart.
It is for both. The numbers in there are for my E67.
Thanks, I was able to build the User Math. I'm so new at this and so old that I forget how to run this thing.
You and me both.
Please direct all gratuities to hjturbo
Sorry Smoke, I wasn't intending to side step your much deserved credit for the thread. My inability to understand what was wrong was from my own inexperience with tuning. I'm still showing some highlighted PIDS in the math so I need to find it whats going on. Screenshot 2021-10-05 233658 copy.jpgIMG_4433 copy.jpgYou and me both.
Please direct all gratuities to hjturbo
Last edited by marksrig; 10-06-2021 at 01:51 AM.
oh no you don't lol. I'm just the spreadsheet guy.You and me both.
Please direct all gratuities to hjturbo
For any red parameter, click on it in the formula and follow the steps attached to get it to suit your vehicle.
Notes:
Clicking the gear icon in step 4 is very important as it restricts the channel choice to those that you are logging.
The parameter unit must match those already outlined by smokeshows formula in post #1.
After using it for a few months this will start to happen. Nice overlayed lines.
That’s friggin beautiful. I’m not there yet. Assuming this is just steady state in one gear.
Last edited by ttz06vette; 10-06-2021 at 09:47 AM.
So I have the PIDs from the math logging so why are the zeros there? They should have values. I am logging the correct WB's, 2312 and 2126 from the beginning. This is confusing, should populate
Many thanks. I've been trying to use this method and your spreadsheet just adds more useful tools. Thank you very much for sharing.
Agreed!
Can you post a log?
Thanks. Yes steady state cruising. Good filtering and smooth throttle changes are mandatory to tune using this method.
Are you manual or auto? Care to share your filters? That is impressive. Im getting there, but it has been a battle being manual.
I think I see whats wrong. The math says 50070 is Engine Speed. My E67 doesn't have 50070 only 12 or 2135 for RPM. I plugged it in and its logging error
Thank you
Auto with a high stall that is unlocked until 6th. Manual will be much harder for sure. Here is another example of what we need to try and achieve. Accelerating through the gears, this snippet is 60 to 90km/h at a constant 40% throttle. Only the closed loop filter is active so open loop GMVE is ignored in my histogram. Also note that the gear shift is ignored for some time either side to allow things to settle again.
A good tip given to me by 07GTS is to put your filters into a math parameter and plot them so you can see when they are active or not. Its a bit more maintenance when making filter tweaks as you have to keep them in sync across math parameter and histograms but it's worth it once they're all dialled in as you can have a lot of confidence in the data you are capturing.
Closed loop filter
[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
Open loop filter
[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
Great.
Probably should have added instructions so I'll add them here.
Find out what the IDs are that you are logging for these parameters:
- Mass Airflow
- STFT Bank 1
- LTFT Bank 1 (Optional depending on tune config)
- STFT Bank 2
- LTFT Bank 2 (Optional depending on tune config)
- Wideband Bank 1
- Wideband Bank 2 (Optional)
- EQ Ratio Cmd
- Engine Speed
- Intake Manifold Absolute Pressure
- Volumetric Efficiency
- Manifold Air Temp
Head across to the spreadsheet and plug your IDs into the blue ID column.
Copy smokeshows formula(s) back into your math parameter(s)
The use of average is optional. I use an average of 200 for closed loop in all my logs as it seems to line up the GMVE data with the O2 sensor swings nicely. For open loop I do not use average. Play around with it to suit your own tastes.
Last edited by hjtrbo; 10-06-2021 at 03:48 PM.
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