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I like the look of the GReddy and the fact that it tells you the actual RATIO not an LED in this range is good and an LED in this range is bad. :roll: Someone on the Yahoo leist has this meter and says it is pretty close to the W/B on a dyno he used.

Check this link out for a big-'ol-comparo!

http://www.alltrac.net/tuning/afgauge.html
 

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What do you want the A/F gauge for? If you just want a warning gauge you can use the Autometers and the like that use the factory 02 gauge. Basically all you are buying here is a display so chose whatever looks the best. If you want to do tuning wideband is the way to go. There is a lot of options now for these. You've got everything from the DIY ones for a few hundred dollars up to the Motec ones that are $1500. Nice things about a lot of these is that you can datalog them on a laptop. On my Greddy gauge there is no playback or datalogging. Driving fast and watching a gauge is never a good combination. The Greddy isn't a true WB but mine matched the dyno WB # for #.
 

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Discussion Starter #4
I am just thinking about a gauge. I am going to Dyno my engine but I want to get a few miles on it before I hit the dyno to break the engine in. I figured that for under $100 an af gauge is cheap insurance if they are the least bit accurate. I would feel better if I could turn it on once in a while and know that I am getting enough fuel with the ct26 converison I am doing.

Mark
 

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Aaron is right -- an a/f gauge is a waste of time based on everything I've read.

If you want something worthwhile get a wideband O2 with datalogging and a display... otherwise save your money.
 

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_HOT_M16 said:
...an A/F gauge is useless?

how about those useless oil pressure gauges, and water temp gauges...

I would never turbo a vehicle without one...
Have you ever seen an A/F gauge in action? They're a waste of time.

The readings from these A/F gauges are inaccurate and the gauges move wildly. EGT gauges are a waste of time as well.

The only true answer is wideband.
 

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CRF_Rider said:
So if the A/F meters are taking the voltage from the stock O2 sensor and you say that they are worthless then how can the ecu make adjustments based on that signal?

The ECU works in micro-seconds,and can use the info.If you have ever been in a car with an A/F gauge,like quick said,they are very erratic.The only time they are stable,is at idle or WOT.Does not help thru the rpm band.EGT gauge is even worse,by the time the gauge tells tou,you have a problem,it's usually toooooooo late :!:
 

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Discussion Starter #10
I did read that they are only accurate at WOT (or Usable) but I would think that that is really where you want to get the accurate feedback anyhow.

I think for $75 I will get one and have it running on while I have it on the Dyno to see if it is accurate at WOT.

Wouldnt it help in detecting a bad O2 sensor?
 

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CRF_Rider said:
Wouldnt it help in detecting a bad O2 sensor?
Depends. Many of them ship with their own sensors.

It's your money, but unless the gauge has some kind of warning indicator it's going to be even more useless.

You're better off saving up the $700 for a true wideband ... get the datalogging option and you can tune the car yourself.
 

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Oh yea... $55 as compared to $700... pffft!

Its nice that you have this great opinion, but telling people to not buy A/F gauges on a custom turbo setup is ludacris. I personally will purchase a DawesDevice gauge to integrate into my dash when I go 5mgTe and probably build another more detailed one, to stick somewhere when I'm tuning.

Hey silvermk2, which gauge do you have? 60mm electronic?

--BillyM
 

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_HOT_M16 said:
Oh yea... $55 as compared to $700... pffft!
I'm not sure what you're implying here, but my point is valid. You get about 1/50th of the value of a wideband O2 sensor for your money. Why waste the cash for an expensive gauge that doesn't help you? You're better off with oil pressure/temp and a fuel pressure gauge.

Its nice that you have this great opinion, but telling people to not buy A/F gauges on a custom turbo setup is ludacris. I personally will purchase a DawesDevice gauge to integrate into my dash when I go 5mgTe and probably build another more detailed one, to stick somewhere when I'm tuning.
Billy -- let me ask you a couple questions:
- Is there a reason to get an A/F gauge?
- What are you expecting it to tell you?
- Do you have the ability to drive while taking notes on the A/F at the same time in regular intervals?

Sounds to me like you want to do things on the cheap. That's understandable, but you're not going to get the safety net that you're hoping for with the parts you're talking about.

The A/F gauge isn't going to do you any good if it's inaccurate (and these almost always are twitchy and inaccurate). Furthermore, if you want the bare minimum usefulness from such a gauge you're going to want the kind with a warning light so that you will notice when there's a problem.

The problem is that the A/F fluctuates so much that the warning light will be going on and off repeatedly. Do you understand now why it might be a bit impractical?

My opinion is based on fact and experience -- you're throwing blind assertions around with no proof to back them up.
 

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Discussion Starter #14
If I run the car at WOT on a dyno that utilizes a Wideband sensor and I get the car tuned so that the A/F mixture is running where it should be (a little on the rich side from what I have been reading) and the gauge corrisponds to the dyno's wideband then how is it useless? I grant you that I would never want to tune using the gauge but if the gauge starts going lean constantly sometime down the road (again at WOT) then that would tell me I need to put it in a wideband again and figure out what is wrong.

I will ignore the gauge unless I am at WOT.
 

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Not that I'm an idiot or anything (with cars i am :) ) but WOT stands for wide open throttle right?
 

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Not that I'm an idiot or anything (with cars i am :) ) but WOT stands for wide open throttle right?
 

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So silver's is the only gauge that is accurate?

I do notice if any of my gauges are different than usual, watertemp, volts, oil pressure are always being watched. I will not be able to run to the dyno every time I make a change. That and my shit is always breaking. Constantly I'll be running it hard and something will go wrong. Now, if and when it ever leans out, I want my A/F gauge to drop down and tell me that instant. From what I hear, they are quite accurate at WOT, and $50 seems pretty fair as compared to the time and money to replace a set of pistons.


If I were to buy a solid turbo kit from someone, and not beat the shit out of my car all the time, and tune it in one good time, and never mess with it after that, then I would see how the A/F meter would not be so useful.


Anyone other than quick (we allready know what he thinks of these):

What do you think of this one? Very similar to the Greddy unit, but quite a bit cheaper. It probably run off the same internals, just doesn't have the greddy name.

DEFI D-gauge - A/F RATIO
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2411572679&category=33676


--BillyM
 

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The issue with using a narrow band (i.e factory sensor) is that the measurement range of the sensor is well narrow (go figure :) ). The narrow 02 sensor are only accurate around 14.7:1 (stoichimetric), probably within say 14.4 to 15:1. Once you get outside of that range the sensor is basically useless. When you are at full throttle most engines run around 12:1 (maybe more, maybe less). What you see on something like an Autometer gauge is that the gauge goes full peg rich at WOT. So you have no idea if you are running 8:1 (extremely rich) or 13.5:1 (probably not rich enough). This basically makes tuning your fuel system a PITA, this is why you'd need/want a wideband for. Basically what you are getting with something like a Autometer is essentially a warning gauge. If you see the gauge go towards lean you can back off and hope you did no damage. The biggest advantage with a wideband is that you know exactly what A/F you are running at any time. With the wideband you can also have datalogging which is immensely important. The problem with my Greddy gauge is that I usually only get a small snapshot of what is happen when driving around. You get the best reading in high gear and full throttle. Doing 100+ mph starring at a gauge is never a great idea. For doing fuel tuning dyno work is really the way to go. You can drop the hammer all day without having to keep and eye on the road or getting any tickets.

Also the Greddy gauge is 60mm electronic (the only way you can get them). Its a pretty good comprimise between a Autometer type vs a Widband type. Its not really cheap though in the low $300 range. I would go for a DIY or Techedge wideband if I did it again. The prices on widebands have came way down from when I bought mine. The only option then was the $1500 Motec unit.

BTW the factory ECU ignores the 02 input at full throttle or high rpms.
 

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CRF_Rider said:
I will ignore the gauge unless I am at WOT.
If you're at WOT you're going to be looking at the road.
Best of luck with everything. Suffice it to say that we'd choose different methods for monitoring A/F

Are you going to run it in your A-pillar pod? Just make sure it's visible regardless. :)
 
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