Trouble when tuning with LM-1 and Wideband commander (VEC2)

[Schulmann]

Hi Tuners,


Finally Innovate released the new XD-1 gauge that I installed in my Viper.
I have now two wide band oxygen sensor tools in the viper connected to my VEC2.

On the driver side I have a Wideband Commander.

On the passenger side I have an XD-1 connected to an LC-1.

To my surprise the AFR output doesn't much between the tools.
First I thought that I had a trouble with the supercharger but quickly I elliminated this point.
To compare the two tools, I have connected both of them to the passanger side.


WBC indicates always 0.6 AFR higher values when under boost.
I can see this difference on the VEC2 log sheet and on the gauges.

(WBC is in my header and the XD-1 is in my tail pipe in place of the rear oxygen sensor).


At vacuum this trouble is not noticable.

In addition the values logged by the WBC, the value displayed on the WBC gauge, and the values on the WBC analog output doesn't match (+/- 0.2AFR). I have the impression that this WBC is only a toy.

Anybody has an idea what is going on ?

 

[KenH]

What makes you think it is the WBC that is reading incorrectly rather than the LM-1? Have you compared either to a dyno A/F reading? Also not sure how you can really compare the gauge reading to the logged reading. I know I can't watch the gauge close enough to tell .2 AF difference between the two.

I have used the WBC on one bank and a dyno WBO on the other bank and seen a similar difference as you are seeing, but I assumed the banks were running different. Now you have me wondering.

 

[Viper Specialty]

Three questions:

1. Is your ouput for the LM-1 configured correctly for the VEC2 input? (0V/10.00 AFR, 5V/18.00 AFR)

2. Are you using Sean's default log file set up specifacally for the LM-1? I have it if you need a copy.

3. Have you done a free-air calibration on both systems in the same place/time?

Lastly, a comment- It does not surprise me that you are getting different readings between two 02 sensors, especially if the sensors have a vastly different age. as they age, they begin to read lean... hence, free-air calibration. If the two systems were calibrated in separate places, the O2 content in the air could have been just a little different, causing your issues as well.

Have you swapped sensor locations to see if the difference follows the sensor, or remains common to location? That would eliminate leaks, temp differences, atmospheric bleed-back into the exhaust, etc...

 

[Schulmann]

1. Is your ouput for the LM-1 configured correctly for the VEC2 input? (0V/10.00 AFR, 5V/18.00 AFR)

Very good point. Yes I have configured correctly the logs. In fact I have compared the Volt output also. There is 0.4-0.5 Volt difference under boost.

2. Are you using Sean's default log file set up specifacally for the LM-1? I have it if you need a copy.

Yes and I strongly believe that the issue is not here.

3. Have you done a free-air calibration on both systems in the same place/time?

Yes on the XD-1 I did.
On WBC it is not available. Likely it is integrated within the internals.

Lastly, a comment- It does not surprise me that you are getting different readings between two 02 sensors, especially if the sensors have a vastly different age.

Good point.
On WBC I have roughly 5000mi.
However they both move on the same pattern.
In fact the way they move I can even tell the location within the exhaust. The rear one is always late a few 0.1(boost) - 0.4(vacuum) seconds.
At vacuum (cruising) there is not a such issue. At least I can't notice it.

I have 3 new Bosch sensors. I even swapped them in the XD-1.
Next step would be to change the sensor on the WBC (and use the same as on the XD-1) but it is more complicated.

as they age, they begin to read lean...

This might be true.
My WBC has only 5000mi.
The oxygen sensor should be sluggish also and it is not the case.
I will try to install a new sensor (the same as on the XD-1) when I have time.

Have you swapped sensor locations to see if the difference follows the sensor, or remains common to location? That would eliminate leaks, temp differences, atmospheric bleed-back into the exhaust, etc...

Not really but from the readings I elliminated this issue.
WBC is in the header and reads leaner values.
XD-1 is in the location of the rear oxygen sensor: read rich and is always late a couple of 0.1-0.4 seconds.

 

[Schulmann]

Am I the only tuner ?

 

[Jack B]

Schulman:

1. Do you have cats and is the LMI after the cat?

2 The WBC I does not calibrate each time the car is started as does the LMI. This is important as the sensor ages.

3 The OEM systems and the WBC are set to one calibration point (air pressure, humidty and temp). The LMI calibrates on each start-up.

4. The LMI has a cycling rate far greater than the WBC.

5. Innovate will take your O2 and test it on preset a/f mixtures at no charge to verify the accuracy.

6. If you get the LM3 aux box (Innovate) you could run the WBC thru the same native log as the Innovate A/f is logging. Like Dan said there may be some interpretive difference when running thru the Roe log.

7. At wot no one can accurately access the a/f from a gauge accurately, it has to be logged.

8. On the LM1 side, since it is back in the exhaust system any air leak in the piping system will cause distorted readings.

9. Make sure you down-load the Innovate software version 2.0. Run a log thru the Innovate software and compare it with the Roe log, that should answer some questions. If you install the LM3 (aux box) you can also log hp/torque via embedded accelerometers. You can also calculate hp with the Roe logging system, however, any calculations based only on rpm rate of change tend to be inaccurate.

10. Lastly, I have my O2 five ft from the collector, to make sense of the a/f readings I have to offset the log .1 seconds, in other words the a/f at 4000 rpm's didn't happen at 4000, it happened .1 seconds earlier.