What's a good A/F guage setup?

[RedRocket]

I think I want to add one of these soon. Does anyone have any pics of a nice install? I have an AWE centervent boost guage already. I paid through the nose because I like the stock/clean look.

Thanks,

[Devious27t]

if you arent using a wideband you are wasting your time as the stock o2 sensors are narrow band.

the innovative LM-1 is a good option, if you insist on a gauge then AEM has a wideband gauge. if you are worried about how lean/rich you are then i would suggest getting yourself an EGT gauge as wideband are more for people who want to tune their cars and they are not exactly cheap.

[RedRocket]

Originally posted by DVS18t
if you arent using a wideband you are wasting your time as the stock o2 sensors are narrow band.

the innovative LM-1 is a good option, if you insist on a gauge then AEM has a wideband gauge. if you are worried about how lean/rich you are then i would suggest getting yourself an EGT gauge as wideband are more for people who want to tune their cars and they are not exactly cheap.

Cool. What's a narrow and wide band? Is it just a diferent scale?I'm not sure what my best interests would be. I am installing a K04 soon, and with all the posting I am seeing here lately, I'm not sure what is in my best interest. For sure I am worried about running lean, but I do get power greedy and may want to further tune the A4. What do you suggest in my case?

[Daft]

That AEM wideband kit is pretty interesting. I haven't looked up the prices but, I'd imagine that it would cost at least $200.

The key to having it would be to get the gauge's RS232 serial connection going to your laptop so you could log it's output.

[RedRocket]

Originally posted by turbo90awd
That AEM wideband kit is pretty interesting. I haven't looked up the prices but, I'd imagine that it would cost at least $200.

The key to having it would be to get the gauge's RS232 serial connection going to your laptop so you could log it's output.

That's good. I thought an air fuel gauge would just be there telling you on the spot how the car is doing.

So I'm learning now that the data can be logged? I guess that helps you diagnose and fix/tune problems out? How does one go about doing that? I guess I should buy a Vag then huh.

This post was originally just for a visual image of a good place to mount an A/F gauge but I think I'm getting a bit more than that from you guys.

Thanks.

[Devious27t]

Originally posted by turbo90awd
That AEM wideband kit is pretty interesting. I haven't looked up the prices but, I'd imagine that it would cost at least $200.

The key to having it would be to get the gauge's RS232 serial connection going to your laptop so you could log it's output.

iirc the AEM with sensor, box, gauge (which i believe is sold seperately) comes to the 350-400 range. the innovative also has laptop hookup for logging and it does wideband lambda and A/F values. there is another one that a friend of mine that i forget the maker right now but it does wireless connect to his laptop.

[98a4]

The stock Narrow 02's so slow also...the results are not nearly as accurate as they are with a wideband. I know several people who have seriously damaged their engines while their narrow band o2 was reading normal, they have a delay...

[RedRocket]

What is a wide band?

[Mike~p]

yea im with him^
..i thought i could just get any air/fuel ratio gauge an hook it up....cough cough phantom gauge for 40 bucks on sale cough cough

[EVIL-AUDI]

You can but it's not exactly the most accurate of readings. But you will get the blinking back and forth light you desire.

[Mike~p]

ahhh yes....how i love that blinking effect..im just getting back from a trip and i havnt put it in yet

[PDX-Mike]

And it's best to run a second O2 sensor for the readings.

[Mike~p]

does anyone have a writeup or instrustions on how to install it?

[RedRocket]

Originally posted by EVIL-AUDI
You can but it's not exactly the most accurate of readings. But you will get the blinking back and forth light you desire.

Not looking for a blinking light. Just want to know that the car is running optimal fuel mixtures. I couldn't care less for the guage.
Still don't know where I'm going to mount it. I have an AWE boost guage in the left vent already.........

[bitterchild]

the short of it is that the oem o2 sensor is not going to give you accurate readings. The readings are too delayed and skewed to be useful. A wideband will give you some sensitivity to use but the useful life would not be usable for the realtime/fulltime use you envision. If you want to just hook up a guage/meter to your stock o2 sensor you can get the "feel good" and "bling" factor . It doesn't sound like you're writing your own fuel maps anyways so no harm. A secondary o2 reading farther back may give you less bouncy readings but they will be skewed by the catalyst

[RedRocket]

hummm. That was a good post bitterchild. I don't think it's a A/F guage that I need then. All I want is a means of knowing if I ever run at the improper mixture. Would a Vag do? I am really looking for a excuse to buy one.

[98a4]

A VAG Com will tell you if your running rich or lean. There's your reason :) go buy one :)

[RedRocket]

Originally posted by 98a4
A VAG Com will tell you if your running rich or lean. There's your reason :) go buy one :)

Yay!!!!!

Thanks :)

Now where's the best place? I want the real deal, no knock-offs and no shareware version crap!

[Devious27t]

Originally posted by 98a4
A VAG Com will tell you if your running rich or lean. There's your reason :) go buy one :)

a little FYI, the narrowband 02 that vag-com reads is not all that fast and for tuning it is not the best indicator. more so for diagnostic purposes. i will not tell you much better than a blinky 02 other than the fact that it has lambda readings instead of green, yellow or red.

[Daft]

This is very true. The VAG-COM is only using the OEM O2 sensors to build a rough A/F for optimal fuel efficiency. Oxygen sensors can also give you a estimated EGT value too but, that isn't a solid value either.

The bottom line is that if you want to KNOW your A/F, you need a real wideband O2 sensor and a gauge/logger that can read from it. Just like an EGT probe situation, placement of the sensor is crucial to proper readings. You would want your wideband O2 sensor to be addition to the OEM ones, not a replacement. This would require you to drill out and weld a new bung on the pipe before the cat's inlet.

As some people asked about the differences between a narrow band O2 sensor and a wideband O2 sensor:

The differences are the area that is monitored and the reaction time of the monitoring.

The wideband O2 feeds voltage back to the gauge just like a standard heated O2 sensor would but, the voltage readings are more precise and they update much faster. In addition, a standard O2 sensor reads a very small area near stoich (ie. 12:1 - 15:1) and supplies these readings in values from 0.0 - 1.1v. A wideband will give you a much wider (thus the name) A/F range and a wider voltage reading. The voltage -vs- A/F measurements would be like this:

Voltage would start at about -5v at 10:1 A/F, moving up sharply to about -1v at stoich, then progressing slowly up to maybe +2v at 25:1.

This is how you can know exactly what your A/F is. Even if it is waaaaaaay of the charts, you'll still know what it is and then you can gradually pull it back into range with software adjustments.

Narrow band O2's will tell you the car is stoich and it may actually be too lean because the window of A/F is too small. In the end, the blinky gauge from Autometer or Cyberdyne will lead to problems when you use it as a guide for tuning.