what is the relationship between a narrowband o2 sensors voltage readings and the air fuel ratio other than that .5v is stiochiometric.
are the readings above and below linear, is there a voltage to AFR ratio?


also posted on tech.

 

it is not linier. it has good resolution from about .2 to.8v. rich enough for boost (12:1) roughly corelates with .9v which is on the very edge of the usable part. not ideal.

 

yup, the narrow band is fairly accurate from 14:1 to 15:1 but outside that range, it blows.

 

thanks alot guys, finally people who can give me intelligent responses.


have u guys seen this, im undecided if its complete cack yet, not like id every buy one, but id just wire a bunch of resisted leds in parallel so one comes on progressively after another as voltage increases , same way as these things are, take a look,

http://gadgetseller.com/gauges/

heres also a site for a DIY wideband controller! GOO ACCURACY!

http://www.diy-wb.com/

 

I'm in the process of building the DIYWB controller. can't wait for the parts to get here I only have 98 bucks into it including materials and a used sensor.

 

i cant get a grip on what the gadgetsellers/com deal is......

DIY-wb.com is kind of lost its previlance. The sensor it uses, the L1H1 is very hard to find under $150. and the needed stuff is around $100 plus hours of soldering so basically its not all that great of a deal anymore.

Basically from what ive seen the best way to go is find a WB that uses a LSU4 sesnor. They basically have the same accuracy as the L1H1 sensor but the LSU4 is only about $35 shipped to your door. you really cant beat that price. I'm still trying to find a device that is reasonable in price and does a good job with wideband readings and such. The PLX device is moderately priced at $300 or less but lacks many options. but the one great option it has is a conversion to narrowband. this will allow you to datalog through your ECU accurately. not to mention the display is huge and the unit is small. I would still like to find a unit almost exactly the same for $200 or less.......We can only dream

 

u can use the $35 VW sensor with the techedge.

 

With the V.2 techedge yes. And I trot out the tired old wideband thread that is in dire need of an update:
https://honda-tech.com/zerothread?id=635792
-PHiZ

 

the techedge unit doesnt have wideband to narrowband output so it cant be used as the lambda reading for DIY datalogging through DIY ecu-editing programs.

PLX device is fast, big ******* display, and has both narrow and wideband.

I would like to find something like the PLX device for like $150-200 with the sensor. that would be grand.

 

has anyone thought about a diy on LSU4?

how many wires come out of that,

voltage 0-5?

how does the voltage correspond to ratio on those ones?

 

http://www.cmperformance.com/techinfo_oxygen.html

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18b1hmtlove &raquo;</TD></TR><TR><TD CLASS="quote">the techedge unit doesnt have wideband to narrowband output so it cant be used as the lambda reading for DIY datalogging through DIY ecu-editing programs.</TD></TR></TABLE>
misinformation.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nickromeo &raquo;</TD></TR><TR><TD CLASS="quote">has anyone thought about a diy on LSU4?
how many wires come out of that,
voltage 0-5?
how does the voltage correspond to ratio on those ones?
</TD></TR></TABLE>

It's not that simple at all, it takes a very sophisticated calibration circuit and a circuit to maintain the proper sensor temperature.
-PHiZ

 

what im tihnking is that

0v = 100% fuel
2.5v=stioch
4v=100% air

seems linear to me!
(even tho i didint calculate values in between) please correct me, im prolly wrong.

as for calibration get a circuit to make sure that its comparing it to 100% oxygen.
as for temperature, like you said a seperate circuit can maintain a constant temp on the o2!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18b1hmtlove &raquo;</TD></TR><TR><TD CLASS="quote">the techedge unit doesnt have wideband to narrowband output so it cant be used as the lambda reading for DIY datalogging through DIY ecu-editing programs.
</TD></TR></TABLE>

it has a simulated narrowband output, besides which you can use it to datalog the wideband values in any case together with RPM and three 0-5v inputs

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kpt4321 &raquo;</TD></TR><TR><TD CLASS="quote">http://www.cmperformance.com/techinfo_oxygen.html

</TD></TR></TABLE>

Hey that place is only 1/2 hour from me. That little article sums it up pretty succinctly. notice how they say the stock O2 is like a switch as far as the voltage signal.

nickromeo - It took a long time to develop the current diywb. I agree that the LSU4 DIY would be great but it won't come quickly i'm sure.

I'm gonna stick with the L1H1 DIY WB for now. There is no other way I can get a WB for under $150 so i don't feel that it isn't an option like others do. Although a used sensor may be a waste of time but for 45 bucks i'm gonna take the risk.

 

Just doing a little searching and I found this. I bought the PLX m-300 a couple days ago for $320 shipped form streetrays.com. It's a plug-and-play unit so install is as simple as screwing it in and running a power wire. I am going to make a setup so I can plug the unit into my cig lighter. Also, I bought a converter for my AutoMeter Air/Fuel that turns it's readings into wideband, it was only $40. As you can tell I don't want the bright *** red PLX monitor in front of my face all the time. Oh, and I was wonder about what air/fuel mixture would be ideal for my H22 turbo. I am running .45 bar and on a stock bottom end with E-manage. I was thinking 13.0, but I have seen alot of H22 people on here running around 12.0. Damn that's pretty rich, but I guess you should rather be safe then sorry.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nickromeo &raquo;</TD></TR><TR><TD CLASS="quote">has anyone thought about a diy on LSU4?

how many wires come out of that,

voltage 0-5?

how does the voltage correspond to ratio on those ones?

</TD></TR></TABLE>

I'm using Techedge LSU4 wide band meter. It's 5 wire Bosch sensor.
The A/F reading from 5 wire sensor is not linear, that's you can't just take the sensor voltage reading as A/F ratio readings.
It's accuracy is fine. I try to put an HKS wide band meter to run paraell, the readings are nearly same. HKS is using NTK sensors.

 

Oh, here's the link if any of you are interested in the PLX Wideband Unit.

http://www.streetrays.com/cata...728a8

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EK Ferio &raquo;</TD></TR><TR><TD CLASS="quote">

The A/F reading from 5 wire sensor is not linear, that's you can't just take the sensor voltage reading as A/F ratio readings.
</TD></TR></TABLE>

What do you mean exactly, just the LSU? The L1H1 5 wire O2s voltage DOES corespond exactly with a set AFR scale shown in this chart I stole from http://www.diy-wb.com/v_out.htm

The DIY-WB Controller
Vout Table for Gasoline
Vout Lambda AFR FAR
1.40 0.685 10.08 0.099
1.45 0.695 10.23 0.098
1.50 0.706 10.38 0.096
1.55 0.716 10.53 0.095
1.60 0.727 10.69 0.094
1.65 0.738 10.86 0.092
1.70 0.750 11.03 0.091
1.75 0.761 11.20 0.089
1.80 0.774 11.38 0.088
1.85 0.787 11.57 0.086
1.90 0.800 11.76 0.085
1.95 0.813 11.96 0.084
2.00 0.827 12.17 0.082
2.05 0.842 12.38 0.081
2.10 0.857 12.60 0.079
2.15 0.872 12.83 0.078
2.20 0.889 13.07 0.077
2.25 0.905 13.31 0.075
2.30 0.923 13.57 0.074
2.35 0.941 13.84 0.072
2.40 0.959 14.11 0.071
2.45 0.979 14.40 0.069
2.50 1.00 14.70 0.068 *
2.55 1.037 15.25 0.066
2.60 1.077 15.84 0.063
2.65 1.121 16.48 0.061
2.70 1.168 17.18 0.058
2.75 1.219 17.93 0.056
2.80 1.276 18.76 0.053
2.85 1.337 19.66 0.051
2.90 1.405 20.66 0.048

4.00 Free Air
* = Stoichiometric Point
AFR = Air/Fuel Ratio
FAR = Fuel/Air Ratio

 

I mean the V output vs AF ratio is not a straight line ratio. Try to see the V. output vs Lamada graph in techedge.

http://techedge.com.au/vehicle/wbo2/wblambda.htm

 

oh, I gotcha now