Sorry! A/f Ratio Hook Up ??????

[jbj454]

Sorry, but I've searched and cant seem to find the answer. I need to know which o2 wire to connect my A/F ratio guage to. I think there is 3 of them on stock o2 sensors. Thanks in advance.....

 

[tunedin302]

I believe it is the black wire but not 100% sure. Take a volt/ohm meter and put one prong to ground (anywhere metal - door jamb etc.) Take the other prong and test each wire. The wire you need will show a constantly changing voltage. Good luck.

 

[flyinghi3]

there should be two black wires and one white wire off the 02 sensor. the wire from the A/F gauge gets hooked up to the white wire on the o2 sensor. if its two white wires and one black wire that comes off the o2 sensor, then hook it up two the black wire.


hope this helps

 

[Daggar]

The reason you can't find and answer is because you're spinning your wheels. Just hooking a guage up to a narrow band sensor gets you nothing but a light show. Your nose is a better indicatior of your actual air fuel ratio than that setup will be. hehe

Good luck with it.

 

[flyinghi3]

its two white wire and a black that come off the o2 sensor. hook it up to the black wire. i found and old post about this.

 

[jbj454]

thanks fellas. I've heard that its a waste of time, but I have a buddy that runs a 331 on nitrous and he truly believes in his A/F guage. He gets his car dyno tuned, but still reads his guage when tweeking. He changed his nitrous system to a better system, but didnt take it to get dyno tuned and used his A/F ratio guage instead. Just this past weekend he ran a 10.55 1/4 mile at Alabama International dragway in Steele, AL., on the spray that he assumed was safe using his A/F ratio guage with stock o2 sensors. I could ask him, but I forgot when I talked to him last. Thanks fellas once again.

 

[tunedin302]

Just hooking a guage up to a narrow band sensor gets you nothing but a light show. Your nose is a better indicatior of your actual air fuel ratio than that setup will be. hehe

Good luck with it.

Have to disagree on this one. I find that my a/f guage helps on WOT. It will tell you if you are lean/stoich/rich at WOT and that's about it. However, that's really what matters for most of us. Not to mention the widebands are a little bit of $$. I'd rather get a tune and be done. Then I have the narrow a/f ratio guage as a montior so to speak.

 

[Daggar]

Its really not a matter that we can either agree or disagree on. Narrow band 02 sensors just are what they are (unfortunately). They act as more of a switch than an actual sensor to indicate to the computer if what it is doing is correct or not.

Here is an example of O2 sensor behavior. Note that it is basically accurate from 0.95 LAMBSE to 1.05 LAMBSE. It is just a switch around 16.64. .7486 looks to be about .93(13.6) LAMBSE on this particular sensor. This is not the sensor used on Mustangs, but just using as an example. You can't use narrow band sensors to determine air fuel ratio except at 14.64.

I stole this chart from one of the guys on the TwEECer forums. It does a pretty good job if illustrating the narrow band sensor effective voltage range.

So sure... it will let you know if you're very near the middle of the stoich range but that's pretty worthless information if you're running a power adder or nitrous considering that an AFR reading of 12 to 12.5 (considered pretty ideal for a power adder) is out of the readable range of a narrow band sensor.

If you're running N/A and just like the pretty lights then you're in there. Using for tuning purposes though... Your nose will he a better indicator. hehe

I would just hate to hear that someone blew up a motor and some expensinve modifications because they relied upon a narrow band to do their tuning. The $300 to $400 required to purchase a wideband meter is cheap insurance in comparison to a motor.

 

[Daggar]

Oops... that should have read ".95 to 1.05" not "1.5". It's fixed. Sorry for the confusion.

 

[tunedin302]

Oops... that should have read ".95 to 1.05" not "1.5". It's fixed.

Ahh whatever ... leave me alone, I like my light show!! It's even cooler around Christmas b/c I pop in a Jingle Bells CD and cruise around the neighborhood with my "mobile" lightshow. Here is what my a/f looks like depending on how my motor is running:

Lean
View attachment 514800

Stoich
View attachment 514802

Rich
View attachment 514804

I have a A/F guage b/c I LOVE the light show!!

 

[Deleted member 87397]

Where's the best place to install a wideband setup in our cars since they are duals. Don't you want to know what each bank of cylinders is doing? Do they make 2 sensor wideband setups or is one sufficient?

 

[Daggar]

Ahh whatever ... leave me alone, I like my light show!! It's even cooler around Christmas b/c I pop in a Jingle Bells CD and cruise around the neighborhood with my "mobile" lightshow. Here is what my a/f looks like depending on how my motor is running:

Lean
View attachment 514787

Stoich
View attachment 514789

Rich
View attachment 514792

I have a A/F guage b/c I LOVE the light show!!

HAHAHAHA ... where can I get one of those?????

 

[Daggar]

Where's the best place to install a wideband setup in our cars since they are duals. Don't you want to know what each bank of cylinders is doing? Do they make 2 sensor wideband setups or is one sufficient?

There are a couple of options:

You can install a single 02 sensor into the leanest bank (which on a 302 is usually the left bank)

You can run 2 WB sensors, one in each bank on a meter like the Innovative LM-1

You can install the WB sensor into either bank and put ensure your tune is in the middle of the ideal AFR range for your application.

In my particular case, I'm running a single WB02 sensor in the right bank (due to positioning issues) and am shooting for an Ideal range of 12.1 to 12.5 AFR under boost. I tune the car to hover right around 12.3 AFR under boost and everything stays happy! I also tune so that AFR is right around 14.5 when not in boost (which isn't too often with a twin screw) and and idle of about 14.5 as well.