Wideband Transforms

[anniversaryss]

I'm setting up a wideband in VCM and I'm pretty sure I got it right. Just a few questions running my LC-2 over analog.
When I transform I use eq ratio to run lambada. Under function it says (v/5) + .05 = output

I'm assuming this is the correct function and I do not have to create a user defined parameter?
I noticed every other wideband has a different function most likely per manufacturer, so I assume this is the correct one for mine?

Also when I set up my graph and error I know what axis I use but for high , mid and low do i input my lowest lambda i plan on reading, mid as 1.0 and my high as what my highest lamabada I want to record?

Thanks in sure I'll have more questions.
Bobby

[mowton]

Grab the Wideband manual and use our Wideband transform generator....Basically the transform is the voltage range divided by the AFR/Lambda range...If another manufacturers transform is the same then yes you can use it. The only time you would have to generate a User defined is if you can't find an HP Tuners provided can transform or you need to adjust the offset to get the gauge/HP Tuners to match.

Ed M

[anniversaryss]

Thanks Ed but I'm not seeing an offset in the directions. Maybe they would show up in the LM programmer? I am unsure.

[anniversaryss]

Wait now I get it.
So the DEFAULT function offset for the wideband in VCM is for the DEFAULT wideband setup.

So if I was to keep the volts at 0 to 5 v but change the ratio to a different number I would plug the new numbers into the offset calculator and then put the offset in as "user defined"?

[mowton]

I could have been clearer in my above explanation. The Transform Offset value is actually the 2nd number in the transform equation. It represents the lowest AFR/Lambda value from the WB spec sheet. The offset I spoke of above should have been stated as analog offset developed based on the difference of the WB output and the MPVI input voltage. This can experieince noise, voltage drops etc which can cahnge the value the MPVI actually records. You adjust the Transform Offset value up or down to move the reported HP Tuners WB value to get them in-line.

Then there is one more confusing thing...Most Widebands are "programmed" to display 14.68 at Stoich...but, when we fill our tanks with anythin other than E0 fuel (pure gas), then the actual stoich AFR value will begin to drop. For example we normally change the stoich AFR value in the tune to 14.1/14.2 to compenate for the 10% ethanol being used today. So immediately your commanded AFR wil be 14.2 while the wideband analof value supplied to the HP Tuners transfoem will be 14.68. So now you have to adjust the Transform Offset value accordingly. It is not a perfect linear relationship so you may see minor variances as you go up in airflow but it is the best we can do.....unless you use Lambda. This is the actual format that the WB controller/sensor uses and arbitrarily assigns the 14.68 when ever it sees a lambda value of 1.0. So usintg Lamba will preclude the AFR variances..much easier.

Ed M

[anniversaryss]

So the limits stay the same as defined by the user manual but the offset is only needed if the wideband and VCM do not match up?
And to change the offset it's the second number that changes.

[mowton]

So the limits stay the same as defined by the user manual but the offset is only needed if the wideband and VCM do not match up?
And to change the offset it's the second number that changes.

Yes sir....

Ed M

[anniversaryss]

Yes sir....

Ed M

See i would get it eventually hahahah

[DSteck]

If you have to compensate for a ground offset, your wideband is wired poorly.

Treat the problem, not the symptom.

[mowton]

If you have to compensate for a ground offset, your wideband is wired poorly.

Treat the problem, not the symptom.

Hey Dave, hope all is well...the Calculator I posted above defines Offset and includes the wiring issues and how to correct.....

Ed M

[anniversaryss]

If you have to compensate for a ground offset, your wideband is wired poorly.

Treat the problem, not the symptom.

Good to know. I'm not having offset issues that I know of bc I have not even tried logging my wideband yet. I'm trying to learn what I need ahead of time in case the issue arises.

I also noticed that there is an "external section" to this part of the forum. Thanks for putting up with me lol.

[anniversaryss]

Is it possible or is it ok to leave the gauge reading AFR but log Lambada VCM and histogram..

[mowton]

Is it possible or is it ok to leave the gauge reading AFR but log Lambada VCM and histogram..

Yes if you have a gauge hooked to your LC-2. The yellow wire is analog 1 and the Brown wire is Analog 2. Go into the LM Programmer while connected to the LC-2 and configure Analog 1 and 2 accordingly.

Ed M

[anniversaryss]

Thanks Ed that's how I have it wired. I still gotta go into log works and do the brown wire outputs when I'm around the vehicle.