With PowerFC DataLogIt (hack box to mimic the proper software, for those not following the progress on this ECU) just about available people in that forum are discussing wideband O2 sensors.

Someone posted this link http://www.techedge.com.au/vehicle/wbo2/default.htm
to a site selling a build it yourself "wideband" sensor controller for about $40 (the board and the electronics and display). Coupled with a specific O2 sensor (used in "lean burning" Hondas) that can be had for ~$150, you've supposedly got a working wideband.

I'd much rather spend $200 and a few hours soldering than $1200 for an off the shelf solution.

But I don't want it if it's not worth it.

Anybody know anything more about this project that what the website says?

 

We use the Motec wide band, I bought this (very expensive) kit as I have minimal electronic knowledge and it would be used commercially and hence hopefully pay for itself. had i got DIY electronic skills and plenty of spare time i'd have had a go building this kit. I am a member of the diy_efi forum that instigated its manufacture, and have not read any bad feedback so far. For the money it has to be worth a go, surely?

 

A friend and I have bought a bunch of the circuit boards (in case of mistakes) and have soldered 2 of them already and are waiting for the o2 sensors.

Total cost is approx $150 USD each. I will be tuning with it on the street as will he (just finished turbocharging his 3400 powered Fiero which will be ungawdly fast).

We are just in the process of burning a board that will have either a lookup chart/or inverting and rescaling the output to allow us to use an A/F gauge (for example autometer) and have it read onto that for an analog display, as well as an LCD display. You could also use a voltmeter if you don't want to spend any more cash.

Just a matter of waiting for the sensors to arrive any day, and then weld in a nut to screw in the sensor.

THe only problem I have to wait for is spring as the 5 inches of snow will make it difficult to drive the FD.


I will let you know how it goes.

the_saint

 

Uggh. I wanted to beat myself senseless the first time I found that link. We paid big $$$ for a real broadband here at the shop less than a year ago. I am an Electrical Engineer/Physicist by trade, so I had to spend some time studying the schematics in detail. The design is very straightforward, and would only benefit from an imbedded calibration curve (linearization of the output) -- which is basically what the_saint is alluding to above with a lookup table. The biasing of the design favors accuracy on the RICH side, which is where we need it! Probably within .1 lambda in the 10:1 to 11:1 range, but probably double that below stoich where rotary owners could care less. Now that I reverse engineered their design, I am tempted to crank out a few completed units with linearized 1volt & 5volt output, in addition to bar graph + numeric output. The would allow you to use it as a broadband data logging source on cheap ECU's without any post-processing required on the output, although TEC's and MOTEC's allow for calibration curve entry in the software. Anyone want our old unit so I can build TEN new ones for the same price?

George
sevenspeed.com

 

Hey George,
Nice to see you around the forums, been a while. How's the shop doing? Got any good RX-7 business? I've been meaning to stop by sometime but just really haven't thought of it when I'm out and about. How late are ya open? And if you ever need an extra hand you know who to ask ;-)
Anyways maybe you can pass along the "namebrand" wideband to a gullible *cough* supra owner or something of the likes and put the money down towards a dyno ;-)

 

all o2 sensors vary their voltage output for a give A/F ratio depending on EGT. I'm not talkin about when it's cold tho i'm talkin about when it's hot cos you've got the hammer down. So unless it has circuitry to compensate for this then it's gonna be inaccurate. You will not get an accurate reading at WOT.
Motec, Autronic and now Fueltronics in Oz have temp compensation...

For more info see this link

http://www.autospeed.com/A_0618/page1.html

 

Ahh, here's where my thread went. Whichever mod moved it, why not link to it here from back in the Single Turbo forum? I posted in there because all the really serious tuners are in there, and there's MUCH less signal to noise ratio than in the general forums. Oh, well. Either way. I got enough replies to make me happy.

Thanks to everyone that replied, by the way.

For the price, I'm gonna check it out. It won't be hard to run this one in an extra bung, and then use the known accurate wideband at the dyno up the tailpipe and compare their results with a couple passes.

 

I'm going to order the Oz DIY-WB. My brother is experienced at assembling PCBs and he has volunteered to put it together for me. I know, I'm very lucky.

It will probably be awhile before I get it up and running, but I'll post the outcome/story when it is completed.

Does anyone have any leads on a place to get the best price on a NTK oxygen sensor?

 

Exit13B,
Why don't you build the 10 new ones and we can buy them from you?
Don.

 

To Exit13B,

I just ordered the Oz DIY-WB. Where can I get the best price on a NTK oxygen sensor?

Would you please share a little more detail on your calibration thoughts/advice with me?

 

JONESBORO......This seems to be the cheapest one I have found yet The Parts Bin, or go to their catalogue entry - C5010-75044 for 121 bucks. I got that off the techedge site in the Sensor section. Had no idea there were so many people doing this project. I've got one on the way and another on order. I've limited skills so I've found a trained professional to do the work. He works for peanuts.

 

Yeah I'm trying to get the O2 sensor... gave up on NAPA and just placed an order with thepartsbin. Hopefully that will work out. I need this thing working!

Brian

 

WARGASM...YOU TOO????? I want to take this opportunity to thank you for the lead for the compression tester. It was 125 bucks and he had a new one for 225. Have not used it yet. Too many projects going on like this OZ wideband. Is yours built yet??????

 

Nah, I haven't gotten all the parts yet. I'm looking forward to it though! I can't wait!

Brian

 

I understand what a wide-band o2 sensor is and what it is used for, but answer me this, when this thing is finally assembled, how are you supposed to use it? Can someone give me some detailed instructions lets say for someone to use it on their stock third gen, and for somebody that just installed a T78, how are you supposed to use it to tune the car? Thanks a lot guys.

 

Got my kit in the mail today. This is a nice little setup. Much more polished than I was expecting. Hopefully I'll be able to assemble it and get it working soon.


Papa Smurf, I can't give you detailed instructions. It depends on the rest of your setup what you'd wind up doing exactly. Ideally you'd plug the output of the wideband into a data logging device, and record it during a dyno or street run, along with rpm, boost, air temp, exhaust temp, whatever else you can log that's relevent. And then you'll use that data to adjust your setup (fuel maps, timing, maybe fuel pressure, etc). The data logging device could be as simple as a video camera pointed at your guages recording the run, or as complex as a laptop hooked up to your Haltech.

I'm a novice, this'll be the first time I've done anything this advanced, so I can't offer any more information. Yet.

 

Could you use this to replace your stock O2 sensor or will this have to be a totally seperate 02 sensor?

 

I got my kit the other day... I've built the PCB for the O2 sensor and tomorrow I'll build the display unit stuff... I hope it works when I'm done with it !

Brian

 

OK,

I got the whole thing built. I have NOT installed it in a car yet... Has anyone else built one of these yet? If so, what does your display read when you run it on a tabletop?

Brian

 

I just thought that if you were to have a big single setup and you went for a fun or boosted it that it might be enough to blow your motor, that is one question that I would like answered. Like I was saying, how do you go for a run and not have your motor go pop?

 

I just ordered the kit with led display today. Anyone know how long they take to ship?

Also, where is the best place to get the sensor, say, online?


-Les

 

I got my PCB and display in two weeks. I found the sensor at "thepartsbin.com" (NAPA was backordered).

Brian

 

Make sure you tell us how it works!

 

ok, this is gong to be a dumb question, so bare with me. I dontundertand what you are talking about and what it is for. Would someone like to take the time and explain for me. I'm not new working on my can but i dont get what you are doing to the o2 sensor.

thanks Kimo

 

Here it is in a nutshell:The O2 sensor that is in most cars, like the Mazda,
is only able to read well around the 14.7 Air to Fuel ratio. Those little blinky lights that people add to the car are really only good for very very rough tuning. The RX-7 likes to run at closer to 11:1 mixture under power. The stock O2 sensor is pretty much useless for that range.
No matter what meter or gauge you read the stock o2 sensor with, it's readings are still 'wild'.

The wide band o2 meter some of us are going to make from that kit, is able to read a much wider range, and with a more stable reading that is not as suspectible to temp. variations.
The wide band o2 can therefore be used to tune a car, and better dyno shops have such instruments.
A wide band meter uses a fairly complex set of circuitry to control it, and to read it's value. You can't just screw in a wide band sensor into the stock location, and read it with a simple meter. It's the whole package that is needed. The cool thing about this 'kit' is it is very cheap. They usually cost from $700 to $2000. This kit costs about $300 or so.
The sensor is from a ultra low emissions Honda.

I hope this helps answer some questions!
-Les