I just bough an auto-meter air fuel guage for future use in my turbo set up, and i have been hearing alot of ****.
I heard from quite a few people that they arnt accurate at all, but then again some other people said they are......fact or fiction??

 

Nothing that uses the stock O2 sensor is going to be anything worth a **** really. To actually get something useful other than a pretty light show you'll need to step up to a wideband O2 (and you'll probably want an EGT gauge as well).

I have an autometer A/F gauge in my turbo'ed coupe and the only thing it's really good for is impressing my friends and getting them to ask me what it's for (there's a story I've told a million times... "you see, in an internal combustion engine, there's this thing called fuel, and this thing called air... blah blah blah")

 

i believe the accurate are the ones that go with a wideband O2 sensor. without it you end up with a nice light show.

also, using an A/f gauge like that one is kind of misleading, becaus the computer cycles the fuel mixture rich/lean for cat. efficiency. you dont really get a true measure of the A/F ratio unless something is grossly wrong, like a cracked manifold, leaky fuel injector etc.

-Chris


EDIT: wow, i got beat too.

 

the air fuel gauge is useless without a wideband o2 sensor, reason being is that an regualar O2 sensor isnt accurate it just tells the computer:

Hey im rich
or Hey im Lean
ect

A wide band says to the computer,
Hey 12:1
hey 16:1

an EGT guage would help out better

edit: damn yall fast, i thought i was gonna be first

 

Go Apex'i EGT - very accurate...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alloutmotor &raquo;</TD></TR><TR><TD CLASS="quote">reason being is that an regualar O2 sensor isnt accurate it </TD></TR></TABLE>
Actually it's very accurate in the narrow a/f range it is designed to operate in.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chiovnidca &raquo;</TD></TR><TR><TD CLASS="quote">
Actually it's very accurate in the narrow a/f range it is designed to operate in. </TD></TR></TABLE>

Which is about 1/5th of the total spectrum.

 

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

Which is about 1/5th of the total spectrum. </TD></TR></TABLE>
It's alot less than that I think.

 

The stock o2 sensor that a regular A/F guage utilizes is a narrowband sensor. It only has a range of 0-1 volts. Basically it was only engineered to tell you if the engine is running at stoichiometric conditions (14.7:1). This Stoich level isn't even what you would tune a boosted or nitrous car for, this would only apply to an N/A tune.

A wideband o2 can read from 0-5 volts and gives a much more accurate reading. This is engineered to be accurate and read air/fuel at different levels than stoich (rich or lean).

In other words, air/fuel guages are pretty much useless and don't really work. Check into the AEM Wideband o2 guage. It's a little more pricey (about $440), but it actually works.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chiovnidca &raquo;</TD></TR><TR><TD CLASS="quote">
It's alot less than that I think. </TD></TR></TABLE>

It's either 1/5 or 1/6. I read all about WB02s before I bought mine. I can't remember what site it explained it all either..damn...

 

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

It's either 1/5 or 1/6. I read all about WB02s before I bought mine. I can't remember what site it explained it all either..damn...</TD></TR></TABLE>

Based on the post that I just made above about narrowband being 0-1 volt and wideband being 0-5 volt, I guess you could kind of say it is 1/5th accurate.