Fuel Air Guage

[ClutchBurndout-:(]

hey, did a quick search here, and learnt that people are saying that the fuel air ratio guages you install arnt accurate and are just for show, is this correct? id really like to install one just to make sure my mixtures are fine through the rpm range.

how do you go about installing them? are they wires into the o2 sensor on the dump? any ideas?

ta

[Moodles2]

Just for show, they are completely useless without a wideband o2 sensor.

[ClutchBurndout-:(]

Just for show, they are completely useless without a wideband o2 sensor.

can you explain more about this wideband o2 sensor? is it just a different type of sensor? or is this the probe they shove up your zorst when your on the dyno?

[Hanaldo]

Yes different type of sensor. Narrow band sensors use a very non-linear output, so just uses the outputs of lean (100-200mV) and rich (650-800mV) and has nothing inbetween, so when it calculates the air/fuel ratio it does not have a very broad range and hence will change very steeply. This type of sensor is also temperature dependant, so will change depending on if the engine is warm or cold. So the gauge will tell you that the mixture is stoich and fine, when in actual fact it is bordering on lean and then if something goes wrong your engine will lean out and detonate before the gauge even registers that something is wrong.

Wideband sensors on the other hand have a very linear output of 0-5V, and are not temperature dependant. So they will give a very accurate reading of what your a/f ratios actually are and will warn you well before your engine reaches a dangerous a/f ratio.

[ClutchBurndout-:(]

Yes different type of sensor. Narrow band sensors use a very non-linear output, so just uses the outputs of lean (100-200mV) and rich (650-800mV) and has nothing inbetween, so when it calculates the air/fuel ratio it does not have a very broad range and hence will change very steeply. This type of sensor is also temperature dependant, so will change depending on if the engine is warm or cold. So the gauge will tell you that the mixture is stoich and fine, when in actual fact it is bordering on lean and then if something goes wrong your engine will lean out and detonate before the gauge even registers that something is wrong.

Wideband sensors on the other hand have a very linear output of 0-5V, and are not temperature dependant. So they will give a very accurate reading of what your a/f ratios actually are and will warn you well before your engine reaches a dangerous a/f ratio.

ok so what do these sensors look like? the good ones i mean? are they practical? or are they something only dyno places have?

[Hanaldo]

They are exactly the same as a narrow band gauge, they are a gauge. Wideband just refers to the type of sensor the gauge uses.

A fairly popular brand is AEM: http://www.aemelectronics.com/wideband-air...8af52a2bdk5t456

They are not really practical because they are hugely expensive. They are pretty pointless (read unnecessary) unless you are using it for tuning purposes. So what do you want an a/f gauge for? You may find that an exhaust gas temperature gauge will suit your needs better, as you can use it to 'assume' your a/f ratio and makes for a pretty good general monitoring tool.

Edited August 19, 2010 by Hanaldo

[ClutchBurndout-:(]

They are exactly the same as a narrow band gauge, they are a gauge. Wideband just refers to the type of sensor the gauge uses.

A fairly popular brand is AEM: http://www.aemelectronics.com/wideband-air...8af52a2bdk5t456

They are not really practical because they are hugely expensive. They are pretty pointless (read unnecessary) unless you are using it for tuning purposes. So what do you want an a/f gauge for? You may find that an exhaust gas temperature gauge will suit your needs better, as you can use it to 'assume' your a/f ratio and makes for a pretty good general monitoring tool.

ok, i dont need it that bad to pay alot of money for, its just a precaution thing.

(bolt text) how so? how do you go about setting that up?

[mad082]

as above. the narrowband o2 sensor will read anything richer than about 14:1 as rich and anything leaner than about 15:1 as lean. they will read stoich as anything in the middle.

yes people are right when they tell you that the air fuel gauges that hook into your factory o2 sensor aren't accurate. when you floor it it simply goes into the rich section of the gauge, even if the AFR is leaner than what you want (such as 13.5:1 at WOT).

the only thing they are good for is telling you if your o2 sensor is working properly or not.

and they look cool if you like flashy lights like i do, which is why i bought one back before i even knew the first thing about air/fuel ratios. i just wanted it because it had flashy lights. it could've been a gauge to tell me what the air condition was doing and i probably would've bought it at the time, LOL

[ClutchBurndout-:(]

as above. the narrowband o2 sensor will read anything richer than about 14:1 as rich and anything leaner than about 15:1 as lean. they will read stoich as anything in the middle.

yes people are right when they tell you that the air fuel gauges that hook into your factory o2 sensor aren't accurate. when you floor it it simply goes into the rich section of the gauge, even if the AFR is leaner than what you want (such as 13.5:1 at WOT).

the only thing they are good for is telling you if your o2 sensor is working properly or not.

and they look cool if you like flashy lights like i do, which is why i bought one back before i even knew the first thing about air/fuel ratios. i just wanted it because it had flashy lights. it could've been a gauge to tell me what the air condition was doing and i probably would've bought it at the time, LOL

ha, get one fo yo jazz homes, might even make it faster to!

ok, so what i can do to monitor the a/f rations properly is nothing unless i wanna pay big bucks? that sucks...

[Moodles2]

Wideband sensors themselves are easily damaged by water/condensation so are impractical for daily use (even the cheaper Bosch one is about $200 to replace), plus you would need to get a hole drilled into the side of an exhaust part (dump or frontpipe) for the sensor to go in, as they get damaged easily when they are mounted from the bottom pointing up.

As for kits locally, just an example: http://www.mmsport.com.au/products/955/NGK...Wideband-Sensor

AEM is UEGO is probably the cheapest of the kits at $250-$300 imported from the US

[Hanaldo]

I wouldn't even bother with it dude, it's not really a practical tool for day to day use.

EGT gauges are pretty good because they are affordable, and once you get to know the 'norm' for your car you can figure out if something is going wrong.

[mad082]

ha, get one fo yo jazz homes, might even make it faster to!

ok, so what i can do to monitor the a/f rations properly is nothing unless i wanna pay big bucks? that sucks...

i think you have me mistaken for eps, dumbass

and if you want to monitor your AFR's just stick it on a dyno every 6 months or so. you should notice any issues with it starting to lean out as it won't feel like it normally does (like hanaldo said).

[scotty nm35]

Only useful if you plan to adjust your own mixtures obviously.

My unit cost $250 delivered and is still going strong 8 months later, should last 80,000k's if mounted correctly just like the stock ones.

[ClutchBurndout-:(]

Only useful if you plan to adjust your own mixtures obviously.

My unit cost $250 delivered and is still going strong 8 months later, should last 80,000k's if mounted correctly just like the stock ones.

what unit is that?

yea i think its most practical to just dyno it every now and then...

[Hanaldo]

Not even that man, just get a good ecu and get it tuned by a good tuner. It shouldn't be leaning out unless something is wrong, in which case you will notice and THEN you can take it to a dyno to sort it out. There's no point chucking it on the dyno every so while just to see what the AFR's are doing.

[ClutchBurndout-:(]

i dont really wana change the ecu

my worst fear is that, its only leaning out a tiny bit, not enough to notice when driving, and that it slowly damages the engine...

[defari]

clutch - u can have my brand new autometer narrow band a/f gauge for like 40 bucks if you want (its been in a box in my garage for about 4 years now)

[Hanaldo]

If you're running the stock ecu then you should be fine, they are designed to run very rich

[ClutchBurndout-:(]

clutch - u can have my brand new autometer narrow band a/f gauge for like 40 bucks if you want (its been in a box in my garage for about 4 years now)

i apreaciate it mate, but after reading the above info, they dont look like they work :S

thanks anyway man