So lost on Calc.VE tuning

[Babydeuce]

My brain is totally fried. For the last 2 days, I have been reading everything I can on the Calc.VE method of tuning. If I go to the main post and attempt to follow it, it is completely different than the PDF in the tutorial section. Which one would be the better choice to follow for a beginner like me? Also, neither reference is really clear on what to do if you are not using a WBO2 sensor.

I have a V1 with the most current scan/tune software. I am running a 0411 pcm with 12212156 OS

Somebody please walk me through this.

Jack

[joecar]

Hey Jack,

Calc.VET was named differently than Calc.VE because it is different (it goes further).

Any pdf's you see are always out of date (yes, I'm slowly working on a new pdf).

Follow post #1 of the Calc.VET thread (https://forum.efilive.com/showthread.php?15236-Calc-VET-correcting-MAF-and-calculating-VE-%28in-single-log%29) this is the Tutorial... follow any links in this post as needed.

You should be using a wideband... if you're not then you can't correct MAF (and can't calculate VE) for non-closed loop conditions.

If you have FlashScan V1 then you will need to edit the pid CALC.WO2BEN to use lambda from your wideband (I can do it for you)... which wideband do you have...?

[joecar]

Which year/model/vehicle do you have this transplant into, what does the MAF/filter plumbing look like (are you pulling in cold air...?)...?

[Dirktdolman]

I have been trying for a year and still can't get it to work

[Babydeuce]

Joecar, I was really hoping you would chime in! This is not a transplant, I have a small fleet (3) of ZR2 blazers with the 4.3L that I am trying to squeeze a few more MPG out of. My teenage kids drive them, and pay for their own fuel, so any help I can give them in the efficiency department is well worth the effort on my part. All vehicles are completely stock, minus completely new exhaust with magnaflow catalytic convertes, and Gibson catbacks.

I do not have a WBO2, which is a problem. I have read (others have claimed) that the CALC.VE procedure could be done without the WBO2. Is the CALC.VE tutorial found herehttp://download.efilive.com/Tutorials/PDF/Calc.VE%20Tuning%20Tutorial.pdf not current?

Jack

[statesman]

I do not have a WBO2, which is a problem.

Why have you chosen to tune without a wideband?

[Babydeuce]

They are not exactly cheap, and couple that with having to have bungs welded into 3 different vehicles, it seems cost prohibitive.

[joecar]

I have been trying for a year and still can't get it to workPost a new thread, let start again from scratch...

[joecar]

Joecar, I was really hoping you would chime in! This is not a transplant, I have a small fleet (3) of ZR2 blazers with the 4.3L that I am trying to squeeze a few more MPG out of. My teenage kids drive them, and pay for their own fuel, so any help I can give them in the efficiency department is well worth the effort on my part. All vehicles are completely stock, minus completely new exhaust with magnaflow catalytic convertes, and Gibson catbacks.

I do not have a WBO2, which is a problem. I have read (others have claimed) that the CALC.VE procedure could be done without the WBO2. Is the CALC.VE tutorial found herehttp://download.efilive.com/Tutorials/PDF/Calc.VE%20Tuning%20Tutorial.pdf not current?

JackHey Jack,

Without a WBO2 you can only tune Closed Loop (i.e. stoichiometric fueling)... i.e. you won't be able to tune for excursions away from stoich (e.g. PE).

So with NBO2 only you can correct some of the MAF curve, and then you would have to guestimate the rest of the MAF curve (luckily it is supposed to have a particular curve to it)... and then the VE table is calculated from this MAF.

The pdf is out of date... the most up-to-date tutorial is post #1 of the Calc.VET thread (https://forum.efilive.com/showthread.php?15236-Calc-VET-correcting-MAF-and-calculating-VE-%28in-single-log%29)

[joecar]

They are not exactly cheap, and couple that with having to have bungs welded into 3 different vehicles, it seems cost prohibitive.If you get something like the LC-2 it provides an NBO2 signal for the PCM to digest, and at the same time it provides an analog WB signal and serial comms WB output...

you can wire it up with connectors in a manner that allows you to drive it from the vehicle's NBO2 harness (as long as the PCM does not do PWM on the power circuit to control heating of the NBO2), this allows you to easily move it between vehicles.

[statesman]

So with NBO2 only you can correct some of the MAF curve, and then you would have to guestimate the rest of the MAF curve (luckily it is supposed to have a particular curve to it)... and then the VE table is calculated from this MAF.

If you're going to tune with narrowbands, that's the way to do it.

[statesman]

They are not exactly cheap, and couple that with having to have bungs welded into 3 different vehicles, it seems cost prohibitive.

I understand what you're saying, but engine rebuilds are not cheap either. While it is possible to tune with narrowbands only, it's not something I'd recommend to novice tuners.

[Babydeuce]

Hey Jack,

Without a WBO2 you can only tune Closed Loop (i.e. stoichiometric fueling)... i.e. you won't be able to tune for excursions away from stoich (e.g. PE).

So with NBO2 only you can correct some of the MAF curve, and then you would have to guestimate the rest of the MAF curve (luckily it is supposed to have a particular curve to it)... and then the VE table is calculated from this MAF.

The pdf is out of date... the most up-to-date tutorial is post #1 of the Calc.VET thread (https://forum.efilive.com/showthread.php?15236-Calc-VET-correcting-MAF-and-calculating-VE-%28in-single-log%29)

Thanks for clearing that up Joecar! I would assume that when you talk about the MAF curve not being able to be cal'd with NBO2, you are referring to WOT above 4K RPM. If that is the case, I am fine with only getting the lower areas where the vehicle spends the majority of its time.

If I were to try and do this routine with NBO2's, do I need to add or delete anything in the CALC.txt file? Any deviations from the procedure that I should be aware of?

Also, thanks for the suggestion on the LC-2, would I be able to run that post cat, or does it have to go pre cat in one of the banks?

Jack

[Babydeuce]

I understand what you're saying, but engine rebuilds are not cheap either. While it is possible to tune with narrowbands only, it's not something I'd recommend to novice tuners.
Thanks for the input, I appreciate it.

[joecar]

+1 not recommended with narrowbands only.

statesman is alluding to what happens when engine runs lean at load, ignition knock takes over and quickly damages engine (the higher the load the quicker it happens).

[joecar]

Thanks for clearing that up Joecar! I would assume that when you talk about the MAF curve not being able to be cal'd with NBO2, you are referring to WOT above 4K RPM. If that is the case, I am fine with only getting the lower areas where the vehicle spends the majority of its time.

If I were to try and do this routine with NBO2's, do I need to add or delete anything in the CALC.txt file? Any deviations from the procedure that I should be aware of?

Also, thanks for the suggestion on the LC-2, would I be able to run that post cat, or does it have to go pre cat in one of the banks?

JackNot just WOT and/or high RPM, but any time the commanded fueling was not stoich (you can still induce high load by opening throttle a fair amount at low rpm).

You don't have to edit the calc_pids.txt file, but your transient filter will now have to exclude data for which CALC.CL != 1 (i.e. not equal to 1).

Run it precat.

[Babydeuce]

OK, I think you talked me out of it...

Is there a procedure that does not require a wideband to get the VE table better than factory?

[Road]

Joecar, I was really hoping you would chime in! This is not a transplant, I have a small fleet (3) of ZR2 blazers with the 4.3L that I am trying to squeeze a few more MPG out of. My teenage kids drive them, and pay for their own fuel, so any help I can give them in the efficiency department is well worth the effort on my part. All vehicles are completely stock, minus completely new exhaust with magnaflow catalytic convertes, and Gibson catbacks.

I do not have a WBO2, which is a problem. I have read (others have claimed) that the CALC.VE procedure could be done without the WBO2. Is the CALC.VE tutorial found herehttp://download.efilive.com/Tutorials/PDF/Calc.VE%20Tuning%20Tutorial.pdf not current?

Jack
Unless your fuel trims are excessive then there is no need to calibrate the ve. If you do then you can log your fuel trims instead of wideband in your maps and copy and paste multiply by %. You will be safe using factory open loop tuning on stock motor. In my experience calibrating the MAF corrects fuel trims best. You might try adjusting stoick to the fuel blend you are using first and log fuel trims and tune from there.

Mike

[joecar]

OK, I think you talked me out of it...

Is there a procedure that does not require a wideband to get the VE table better than factory?There isn't...


( you can play with adding/subtracting the LTFT's and/or STFT's...

but the thing is, in CL the load is typically light and trimming usually takes care of any errors in VE and/or MAF as said by Road/Mike above...

i.e. at light load, driveability is not very sensitive to VE/MAF errors, and is still fairly good;

sure, any positive LTFT's are carried over to CL->WOT transitions, but if this portion of the VE/MAF is not correct then you're running the risk of incorrect fueling (lean).

)

( when you snap throttle open and load significantly increases, this is when incorrect fueling affects driveability (e.g. you will feel/see the effects of:f lean misfires, rich bogging, lean knock, rich fouling) ).

[Babydeuce]

Got it, thanks for all the input!

Jack