It's still in it's infancy, but a DIY WB O2 is now public domained.
Trouble is I kinda hide it.
If you *know* me you'll know where and what to look for.
If you don't then your going to have to read the archives at the DIY_EFI, and GMECM lists. Just too many folks been trying to make money on what I've been trying to do (get the word out on efi and home programming). It's for home use and not meant to be a lab grade deivse. It does get around all the switching type sensors problems, and uses a TRUE WB as a WB. There are no guarantees, and it's not a lab grade unit but one that you can take some confidence in it being repeatable. I have over 20 hours on mine, and it's still fine. Your results may / will vary, and not to be used without adult supervison, yada yada.
This is not to be used in lieu of reading the plugs and using other tuning aids.
In it's current form the display is a DVM, hopefully in rather short order there will be a display (maybe in the next week), and maybe a interface to a gmecm
If I hear of anyone passing it around It will be taken down and torn up. Folks are going to have to do there homework to find it. Considering all the commerdial units are over a grand, and the other egor is $600 plus sensor, at $30 (plus sensor) kinda hard to beat this one.
Already guys working on a PCB and kit so hopefully an easy kit will be around (also, this is a NO profit kit).
It's designed for a mechanic that knows who to solder well can build it, it got a little complex to keep it analog, but it's the best answer I could come up with, also being a freebe your on your own for support but I imagine won't be long till there are some in use. That's why there are lists

 

I guess I don't understand what all the bickering is about on the gmecm list regarding this EGOR project. So someone came up with this project (was it you?), decided to make it public domain, and then withdrew support for it when they heard that others were planning on profiting from it?

Is this not a risk accepted by anyone releasing their work to the public? I've seen "legal-looking" disclaimers on other public domain stuff warning against the sale or profit from the free info, wouldn't that suffice in this case?

I guess I don't understand what you're telling us in your message above, either. So, the information on how to build an EGOR is still available somewhere on the web, and is still freely available to anyone that can "find" it? But you'll delete the web page if you find out that the info is getting into the "wrong" hands?

I apologize if I don't have my facts straight, I've been skimming through the gmecm messages fighting over this project. Please correct my mistakes if they exist. I guess I just don't see why everyone is getting so upset about this, over on the mailing list.

 

There have been a few list projects at the DIY_EFI area. Promgramming 101 was the first, there are thousands of hours in that project. I offered to lead the charge to get the 747 hac'd. Now remember this is a few years ago, there was no gmepro as we know it no tunercat no ecmguy.

Then the 808.

Then I started the DIY-EFI Wide Band project. The initial proposal was for it to be a community effort. Rather early Gar coined the name EGOR for this effort. Along the way there were alot of off list emails I might add, researching things. One list member Steve G., mentioned making a few for friends, and Gar went ballistic, then in the researching of EGOR the SAAB stuff for ION was found well *we* the list were at the stage Gar was testing the EGOR, and a Mr Harris tired of Gars chest pounding made some veiled mentions of alerting SAAB and then things really got ugly. Again there was some stuff of list.
It got to where Gar left, and a group of use went off list to get EGOR done, eventually there were just 2 of use, and it took 2+ years for us to get this far.
2+ years, there is a huge amount of time, and I've bought a number of sensors to get this far. Not many folks would put any where near that much time in for a list project. I might add, or you may have noticed about my comments on AFRs and not using WBs as a sole judge, it not like I needed a WB, just though might help others.
So far I have more hours in the DIY_EFI area then in any car I've ever owned. I do it to get folks interested in hotrodding. It's my way of "giviing it away".

Yes, to a large degree I consider it mine to share. I have alot of time, and was the only one to step forward and put my money where my mouth was to get this going. I don't mind spending a little only like this, I just resent folks making money off of my work, and investment.
I expect a man to be true to his word.
This needing lawyers is BS.
If I post something that says not for comercial use, and some low life dweeb reads it and does that, then they are less then slime in my book and I have no druthers in saying so. Legally I ain't gonna get a lawyer, just I hope they rot in the info.. What goes around comes around. It's really funny to watch......

Shortly there will be all kinds of arrows to where it is.
I'm just having it's display rewritten some so that my position is better understood about this as an education exercise, etc..
I'm trying to do good things, and it just gets old seeing some of this chit happen.
Even here on this list a few years ago I couldn't get 6 people interested in Beta Testing the GMEPro stuff. I dare say I've made a difference, so yes, I figure I intitled to be *chitheaded about things*.
Specially when someone uses my work, and then acts like they want to take credit for it. Yep, it's an ego thing, so what?. everyone has one, and I dare say mine's in alot more check then some folks around here

 

I was just wandering, because i've heard talk over the past few month, what is the difference in wide band and standard? This is just for my own personal understanding, heh, i'm one of those messed up guys curious of how things work and what they do when they do work...know what i mean?

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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-Future:
-383 Stroker?

 

The stock O2s are designed as switch O2 sensors. Meaning an output of over .44v is rich, and less then that leaner then 14.7:1. Some firms in order to make a make have extrapolated some numbers to try and make read an Air Fuel ratio. Trouble is there are flaws in that sytem.
A wide band is just that, it will out pur for a specific AFR if it's good, they do wear out and can be killed with silicone like any other O2 sensor. But you can read about 17:1 to 10:1 with some accuracy.

 

This brings up another question. Is it the silicon that affects the sensor or something else (curing agent, etc) in the silicon? I thought there was sensor-safe silicon sealers on the market?

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Aerosol silicon lubricants kill em, so I doubt it's the curing agent.

 

Well thanks for getting me up to speed, I only joined the list a few weeks ago so I didn't have the background info to draw a conclusion. It sounds like you've put up a lot of your own time and money to benefit all of us, you should be congratulated for that.

BTW.. Since we're talking about the operation of WBO2/switching O2 sensors, is the real difference that the WB sensor has a linear response, while the switching sensor is nonlinear? Is that why people caution against using the stock sensor as a tuning device, because people would assume a linear response of O2 vs. volts?

 

Neither of them are any where near linear.

they both have twists and turns in them.
That's why displays are so tricky.
If you do it all digitial not tooo bad but that quickly gets away from anything DIY
Specially if you want an accurate AFR down to 18:1, or 9.5:1 hence why the DIY is not lab grade since so far it looks like were gonna prune it off at 11.5 and 16...
If you can tune to 16:1 (properly)then your at a leave where you want a Lab grade, and if your richer then 11.5 with anything DIY your probably just way off in your tune.
The GN likes 12.2:1 and that might be a little on the rich side.

 

I don't visit this board too often, just happened to be browsing a bit and found more info on the WB o2 sensor schematics I found yesterday. I love it when a plan comes together!! I'm glad you decided to release your plans and hope the "heathkit" version with A/F mixture display and 0-1V interface for replacing my factory "switch" o2 sensor get released very soon.

Anywhoo... I'm curious about a few things,

How were the values for the af/voltage table in the spreadsheet derived? Were they from measurements of air and fuel flow on a test engine under controlled conditions or by comparison to a "known" WB sensor and controller.

The voltages listed in the spreadsheet go from negative to positive. Can I assume this is in reference to chassis ground?

My (limited) understanding of the workings of a wideband is it compares EGO to atmospheric o2 levels. Does this circuit allow for recalibration of the WB sensor or the sensor essentially "self-calibrating"?

Would you characterize this sensor and controller package as "accurate" or "repeatable"? Must exhaust temperature and battery voltage be taken into consideration when evaluating the output of this sensor or are the output numbers pretty consistent given those variables? It looks like there's a reasonably wide spread across the area I'll be tuning for so can I assume that if I'm in the "window" that things are okay as long as battery voltage and EGT are within normal ranges?

Do I ask too many questions?

Again, thanks for sharing the "fruits of your labor" with us.

Rob_O

 

There are two *grounds* chassis, and then an artificial one.
It's been run in unison with several other commercial WBs both on engines and sample gases.
Tehy all seem to got to about 12mv as a *standard* during warm up.
No one has killed one yet so we really only of them dieing and going open like a standard one would.
They are not very temp sensitive as they use their own heater, and that current draw is part of the way they work.
The car that uses them has no provision for recalibrating them, so this is one of those cases where if it keeps the EPA happy for 100K miles it more then likely should be fine long term for us.
I've just been using mine so far as a probe type, where I have a section of muffler pipe with a bung welded in it for the sensor. With one hose clamp I can run it or not, and use it for tuning. Have to admit so far at low speed it is hard to read, since it is so fast. At higher engine loads speeds, then it is easy to read

 

On further inspection of the diagram, I now see that circuit ground and chassis ground are seperate from each other. The few brain cells I haven't killed off with Alcohol are sometimes slow to notice the obvious.

I ask about the calibration because I'm not sure the EPA test cycle includes 30 PSI of manifold pressure on a witches brew of toulene, xylene, tetraethyl lead and other stuff "For off-road use only". I have no doubt that under "normal" situations these sensors will last 100K miles but the stuff we do is only considered "normal" by the company we keep.

Again, thanks for releasing this info. If everything comes together maybe you'll see me at Edgewater/Tri-State/Killcare next year using it.

Rob_O

 

I think its great that someone is doing something like this. It would really suck to spend a couple hundred on a wb02 and blow a head gasket and have it ruined. This would be a great way to keep things cheap for the sport and help with the tuning of fi cars.

 

Just a lil FYI, it is the curing agent in some silicones that will ruin an O2 sensor. I am trying to remember what the name of it is... I got the information from a Permatex technical rep about 5 years ago. The aerosols sometimes have a curing agent in them too, so that doesnt really make a difference. Damn... I just cant remember what the stuff is. It also has a nasty tendency to eat aluminum parts besides screw up sensors. If I remember the name of the curing agent, Ill let ya know.

 

Your asking two different questions.
One is calibrating, and the other the design limits of the sensor.
Boost skews it several hundreths lean, so it is better to read lean then rich, kinda neat inna way for what ever .03 difference in AFR might mean. At 2000dF you probably will hurt it, but you'd already hurt the engine.
Leaded fuel is gonna hurt any exhuast sensing devise. Lead coats stuff, period. Witches brews your on your own. Noone has a crystal ball for that stuff.
Normal is more then just a given few that associate with each other, that's just agreement (their reality) <g>...
I'm easy to find, I have to wear a mask in public, and the car has a *got boost* decal on the rear window under the 3rd brake light.