# Wide Band O2 sensor voltage chart....



## WackyWabbitRacer (Apr 24, 2001)

I am a rookie in terms of using a "Wide Band O2 sensor" but have been SCCA racing since 1991. Have been thinking about using a Wide-Band to fine tune the A/F on a VWMS CIS mechancial fuel system.
Does anyone have a link to a "voltage output chart or graph" for a Wide-Band O2 sensor. 
Can the output of a Wide-Band O2 sensor be captured by a data acquistion unit, using one of the available channels. I am guessing that a Wide-Band O2 sensor outputs a max of 5 volts???
Thanks in advance, WWR.


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## Fox-N-It (Jul 23, 2003)

Some WB sensors are linear(Bosch LSU) and some are non linear(Zetronix). The Megasquirt site has some good info on the different WB options.
The Innovate can output 0-2V or 0-5V to a standalone unit. It can all be logged by the LM-1 unit and later acquired through a laptop for inspection.


_Modified by Fox-N-It at 4:24 AM 6-7-2005_


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## aspro (Jun 18, 2004)

*Re: (Fox-N-It)*

If you are using CIS injection then i think you can only effect the overall mixture not individual LOAD / RPM bins.
Wouldn't this be an expensive purchase to do what you could acheive with the seat of your pants.
You are best of converting to a standalone ecu like megasquirt first, and then you can get all the benefits from a wideband.
For output charts check http://www.wbo2.com  i use the 2EO to send a signal to megasquirt.
0V = 9AFR then linear line to 5v = 19AFR



_Modified by aspro at 10:28 AM 6-7-2005_


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## need_a_VR6 (May 19, 1999)

*Re: (aspro)*

You can tune CIS with the idle screw, shims for control pressure, as well as with different bowl profiles for different flow. It's tuneable enough.
The point though is different WB's have different voltage/afr conversions so which one you're using is important. The Techedge I have has two different 0-5v outputs even, one linear, one non.


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## Scirocco14gp (Feb 9, 2004)

*Re: (aspro)*

Ol' Ryan knows what he's doing! http://****************.com/smile/emthup.gif 
You guys have to think outside the box here...if you make removable inserts for the airflow plate with various cone angles you CAN adjust the A/F ratio at various RPM/airflow rates. 
The wideband O2 sensor is about the only way to record the A/F, and if you add it to a data logger like Race Technologies' DL1 unit, you can store/print RPM vs. A/F charts, the same as if you were on a chassis dyno but even better because now you're recording data in the real world environment the system in operating in, not just sitting there in a shop.
MC


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## WackyWabbitRacer (Apr 24, 2001)

*Re: (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_You can tune CIS with the idle screw, shims for control pressure, as well as with different bowl profiles for different flow. It's tuneable enough.

Paul, I understand the tuning of a CIS mechanical fuel system. I have an adjustable Control Pressure Regulator and have shimmed the System Pressure relief valve. All of the pressures have been set with the CIS Pressure Tester.
Although I use an EGT dual gauge to measure exhaust temperatures on cylinder #1 and cylinder #3, I need more precise information in regard to the A/F mixture.
A WB O2 sensor should provide that information. I am looking at the DL-1 data acquisition and want to make sure that a WB controller is compatible with a DA unit.
According to some study last night, a 12.5 A/F mixture is the ideal power setting. 
By varying the amount of Control Pressure, I can fine tune the Control Pressure to get the best A/F ratio.
Thanks for the feedback, Ryan.


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## aspro (Jun 18, 2004)

*Re: (WackyWabbitRacer)*

I didn't realise that you could fine tune CIS like is stated above http://****************.com/smile/emthup.gif 
The Techedge 2EO works great for me but i am not sure it has logging software like the LM1.


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## need_a_VR6 (May 19, 1999)

*Re: (WackyWabbitRacer)*

I know you know, but other people didn't








Any good 5v A/D can take the signal, but you'll need the curves of that specific wideband to make sense of it. They're all different!
12.5 is a good baseline, but depending on compression, timing, chamber design, etc that changes a bit. My big problem with CIS was that if I got the top end to be about that A/F my midrange was too rich, killing the torque. I think it dipped down under 11:1 AFR at about 4500 if at 6200 it was 12.2:1. Happy tuning!


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## WackyWabbitRacer (Apr 24, 2001)

*Re: (need_a_VR6)*

Paul, thanks for the feedback. Although I use an EGT, the exhaust temperature reading is too "general" to determine the fine tuning of the CIS. At WOT on a long straight, the EGT is about 1325 to 1350 degrees (F).
I just need to save some $$$ to get the new toys. Cheers, Ryan.


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## need_a_VR6 (May 19, 1999)

*Re: (WackyWabbitRacer)*

Ryan, no problem. I'm also using a Techedge 2AO and it works nicely. It does have onboard logging of O2 as well as RPM, a few analog inputs, and EGT (though my board was too early for that it's done now). Paid ~200 shipped for it but had to assemble it myself. 
The newer Innovative might be the way to go for you as it's made to go direct into an ECU or datlogger and doesn't have its own display. 
Hope that helps.


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## WackyWabbitRacer (Apr 24, 2001)

*Re: (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_ I'm also using a Techedge 2AO and it works nicely. It does have onboard logging of O2 as well as RPM, a few analog inputs, and EGT (though my board was too early for that it's done now). Paid ~200 shipped for it but had to assemble it myself. 

What is the degree of difficulty to assemble the "motherboard" of the 2AO?
I have a good electronics background in the computer industry.

_Quote, originally posted by *need_a_VR6* »_The newer Innovative might be the way to go for you as it's made to go direct into an ECU or datlogger and doesn't have its own display. 

Who manufactures the Innovative, or is that the name of the company? It would probably be good to have a display that is "sight inline" with the driver in the event the A/F tuning was off.
Thanks again. I now need to do some research and study of WB sensors/controllers. ...Ryan.


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## need_a_VR6 (May 19, 1999)

*Re: (WackyWabbitRacer)*

Depends on what you've assembled/disassembled before. It's all through hole stuff, so it's not that "hard" just time consuming. There are a lot of resistors in the board and they take forever to stuff and hand solder. Took me about 2 hrs, but I have about a billion and a half hours of soldering experience. I would think a noob would take at least 3-4hrs. If you like this kind of thing it's 'fun' on a level though.
The 2AO has the display which is good in a racecar where you might be interested in realtime AFR. Unfortunately there's no alarm output that can be configured, like low AFR wired though the WOT switch. Fancy but would be cool. I know how you racecar guys like warning lights








Innovative is the name of the company, can't find the website real quick but it's out there. LM-1 is the normal unit I think the LC is the new one. 
Hope that helps.


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## klatinn (Oct 30, 2003)

*Re: (need_a_VR6)*

Hi,
If your CIS system is CIS Lambda, there is a way to tune/control WOT with a wideband (at least with an LM-1 or LC-1







).
I just did that on my daughter's 86 VW Cab.
The LM-1/LC-1 have 2 programmable analog outs. I programmed output 1 to simulate a regular narrowband sensor with a switchpoint at 14.7 AFR. Programmed the second analog out to simulate another narrowband sensor with a switchpoint at 12.8 AFR. Then disconnect the WOT switch at the throttle body so the Lambda computer stays at closed loop all the time. Instead use the WOT switch to drive a relay that switches the lambda computer's O2 input between output 1 and output 2 of the WB. As the Lambda computer does not know any better, it will regulate the control pressure of the CIS with the frequency valve to the 450mV switchpoint of the O2 sensor. But with the output 2 of the WB having a switchpoint at 12.8, it will regulate the CIS system to 12.8 or whatever I program. Still experimenting with the slope of the simulation so it regulates fast enough but without overshooting.

Regards


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## WackyWabbitRacer (Apr 24, 2001)

*Re: (klatinn)*

Thanks for the feedback. My CIS system is purely mechanical with a VWMS fuel distributor.
I am looking at the LM-1 or the LC-1 so I can subsequently capture data on a data acquisition such as a DL-1 unit.
Once I have some AFR data, I can then adjust the Control Pressure and System Pressure. At the time, I only have an EGT reading at WOT, and the EGT is too general for fine tuning. I know I am rich enough to keep the EGT at about 1325 to 1350 degrees (F) at WOT but it may still be too rich.
Thanks again, WWR.


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## Jefnes3 (Aug 17, 2001)

*Re: (klatinn)*

re: 'slope' of the simulation....
Scan the internet for a narrowband response curve.
(no ~too diffcult to find)
copy this into your 'simulator'

the lambda coputer is looking for a ~switching signal.
so you need an almost 'verticle' slope.

BTW: your idea does work...
(I did this on obd2 stuff a while back)
I made the 'simulator' output boost dependent so as to control
afr at cruze, zero boost and ~good boost.
-Jeffrey Atwood


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## plohip (Sep 12, 2001)

*Re: (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_ 
Innovative is the name of the company, can't find the website real quick but it's out there. LM-1 is the normal unit I think the LC is the new one. 
Hope that helps.


It's actually innovate, I thought it was innovative too for the longest time.
Website is http://www.innovatemotorsports.com/

Oh and the new LC-1 looks cool!


_Modified by plohip at 10:59 AM 6-18-2005_


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