A Special tip for Wideband Users....

[S2H]

A little tip to help everybody who owns a wideband or who will be buying a wideband....
there are many companies selling wideband kits for aftermarket performance use.
when deciding on one to buy something that should always be considered is if that company's priduct comes with some sort of softare/hardware option to change how the wideband reports data....

For my Example I will use the innovative motorsports LC1 kit ( this is my example because I use this one in particular)
It comes with some software they call logworks...not much use to us as its pointless software without adding an upgrade that we dont need since we get all of our other data thru the scanner anyways....
but it also comes with some software they call the LM Programmer...which is very useful and it is the whole reason I have made this post.
In the LM programmer it allow you to change several setting of the LC1...
the setting that I am going to focus on is under an advanced setting tab...
a seting that allow you to change the report rate of the output from the default factory setting of instant to a slower setting.
the slower settings on the LC1 are 1/12th - 1.6th - 1/3rd

when we log the scanner reads data as it sees it... but if your wideband can report fast enough to be able to read faster than the exhaust puffs(like the LC1 can) then the instant response could be outputting between a puff resulting in the scanner getting data that says its way lean...a false lean spot...

so whats the fix??

change the output resolution of the wideband

I taked directly with innovative about this setting and asked them what it does...

The LC-1 samples internally with the highest speed the sensor itself can sustain, controlled by the sensor's internal response time. This is about 200-300 Hz(200-300 times a second) on the LC-1. This is also the update rate of the analog outs in instant mode.
When set for example to 1/12th, the LC-1 sums together all samples for a 1/12th second period and counts the number of samples summed so far. When a 1/12th second period has passed, it divides the collected sum by the number of samples collected and outputs that value, which is then the average value over 1/12th second, on the analog outs and resets the sum and counter for the next 1/12th second period. As the logging speed on the serial port is also 12Hz, what's logged is also that average over 1/12th. With 1/6th speed the average over two 1/12th periods is output every 1/6th second. With 1/3rd speed the average over four 1/12th periods is output every 1/3rd second'

with this in mind we should consider this

It's the basic sampling theorem (Nyquist).The sampling frequency to correctly sample a signal must be at least twice as high as the highest frequency contained in the signal

With 1/12th averaging the highest signal frequency would be 6 Hz(or 6 times a second).

in general when I am tuning I am logging enough stuff that the scanner records at 10 frames / second...

What I have noticed is a considerably better tune with using the 1/12 or 1/6th outputs....
1/12 appears to be fast enough to not get a false lean pulse in the middle...
1/6th was just a little better....
No difference when I tried the 1/3rd rate

technically... by the Nyquist theorem we would need it to logat least 24frames a second for the 1/12 output... and at least 12 frames / second for the 1/6th output... and atleast 6 frames /second for the 1/3rd output

I also noticed with LC1 set to the factory default of instant... that if you checked it vs LTFT/STFT it always comes up way rich...like -8 to -12 everywhere And if you check it with the 1/12 or 1/6th setting it is right at 0..+/-2

[Keith@HPTuners]

Good post..

Let me add to it...

Our software also polls the EIO quite often for A/D input as well..

If you are logging at 10 frames per second.., then each frame of data will have EIO data that consisted of 4 polls..

meaning, every frame the scanner builds will be 1 frame from the PCM, and 4 EIO frames that have been averaged into 1 frame for accuracy.

This means that for every 1 second period, 10 frames of data, you will have polled the EIO 40 times for A/D inputs...

If you log at 5 frames per second in 2.0 on a vehicle that can support more than 24 PID's, you will receive 8 EIO frames that make up each individual scanner frame...


Also, with the LC-1 a good idea would be to reprogram its output algorithm to a more useable span. I'm not sure how many people are concerned about logging single digit AFR numbers, or AFR numbers over 18.. Instead of trying to cram a rather large range of AFR (like 7 to 22) into a 0-5v span, a better way would be to log numbers like 10-18 afr in a 0-5v span.

This will help reduce the error effect of ground offsets an other voltage offset issues as well as increase the resolution for the smaller AFR range.

Hope this makes sense, its pretty late here..

[S2H]

With that said.....

knowing that the EIO polls 4x per frame means that at 10 frames per second we have a rate of 40 samples per second on the EIO inputs...
at which point the 1/12th of a second output would be well within the realms of the Nyquist Theorem mentioned above

[xonelith]

Thanks guys for the info!!! This is really going to help me an others who will be purchasing a WB.

I was looking into this info myself when trying to setup my LC-1 and was just about ready to post a question... .

[TRex]

I have noticed similar effects when using the output for NB simulation. Set on instant the WB reads so fast that the PCM thinks it is constantly rich (monitoring EIO input and comparing to PCM 02 channel). The voltage is actually switching, but it is switching too fast for the PCM to catch it. I think it is due to the pulses in the exhaust as well.

I also found that to get the correct resolution I had to slow it down to 1/6th - at that setting it virtually mirrored the NB in the other bank.

Good stuff !

[walterd]

If you program the lc1 for 10-18 afr at 0-5v and set it for 1/6th report rate should you do another free air calibration?

Thanks!

[S2H]

If you program the lc1 for 10-18 afr at 0-5v and set it for 1/6th report rate should you do another free air calibration?

Thanks!

sorry it took so long to respond

you dont need to do a recalibration of the wideband..you only need to recalibrate when you change the actual sensor
Innovate suggests that you recalibrate the sensor periodically even if its the same sensor..especially when you have not used it in a while...if you use it every day..then there is no need to recalibrate until you replace it

[zinner]

So if you have it welded into the cat pipe (before the cat) and it's powered on every time the car come in you should never need to do another free air calibration?

[S2H]

So if you have it welded into the cat pipe (before the cat) and it's powered on every time the car come in you should never need to do another free air calibration?

many companies suggest that you do a recalibration in free air(or after 12-16 hours of sitting in the exhaust with the car off) every couple of months...but your initial heater calibration only needs to be done when you first plug the sensor into the wideband device.


do you need to do the every couple of months free air?? its up to you..I recalibrate mine for every car/truck I tune

[MeentSS02]

Riddle me this...is the EIO polled at 4x any data rate? I log 40 frames per second (or whatever logging 6 bytes will give you)...so is it polling the EIO at 160 frames per second?

[S2H]

yes...
EIO samples at 4x the other stuff

[MeentSS02]

Schweet

[Keith@HPTuners]

EIO will poll 40 times a second or more (varies)...

If you are logging 40 frames per second of vehicle data, chances are each frame represents 1 EIO frame.

If you are logging 10 frames per second of vehicle data, chances are each frame represents 4 EIO frames averaged together.

[Joe6pt0]

(or after 12-16 hours of sitting in the exhaust with the car off)

That's how I calibrated mine since its such a pain to get to to remove. I just waited overnight then calibrated it before starting the car. Everything is reading 14.7 when expected so it seemed ok to me.

[MeentSS02]

EIO will poll 40 times a second or more (varies)...

If you are logging 40 frames per second of vehicle data, chances are each frame represents 1 EIO frame.

If you are logging 10 frames per second of vehicle data, chances are each frame represents 4 EIO frames averaged together.

Ahhhhhhhh...that makes sense. So 40 frames/second looks like the max...

[Luweegy]

What is the setup if I'm using a AEM wideband?

[wesam]

i have the same question ??

[00000D0101]

Same question on the NGX

[afasttransam]

X2 for the ngk

[Millam]

Thinking about this "free air calibration" I get to wondering how often the Honda V-Tec had to recalibrate these during the years that these cars ran?