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Discussion Starter · #1 ·
I posted a similair question in the shop and parts review section but nobody has answered it and I'm looking to get a gauge very soon. Since the display on my WB is pretty small I plan on hooking this AF gauge up to a programmable output on the WB so I have a big red light if I start running lean.

I was just wondering if some gauges react slower than others and if so, which are the fastest reacting gauges? I was going to buy a cheapo Autometer but somebody told me they were very slow to react. Could there really be a huge diffeence in reaction time for a gauge that is only measuring a simple 0-1v charge?
 

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I suggest you purchase an FJO or similar wideband for tuning purposes. The FJO with an LED readout is the most widely used and you really can't go wrong with that unit.

-pete
 

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I was looking into an Autometer A/F gauge as well, but I was told you're are much better off getting an Exhaust Gas Temp gauge.

Supposedly with Autometers, by the time they register too lean, its already too late! :eek:

With an EGT gauge, you can monitor temps and catch them as they are rising.

Thats just my limited knowledge.... hope it help.

Craig K.
 

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Discussion Starter · #6 ·
Magic, I would but the new Innovate unit is completely digital, has more features, is just as accurate, has 44 minutes of datalogging and is half the price. I have already ordered the unit so I'm hoping it lives up to its very good initial reviews.

Craig, I have an EGT but they are sorta useless too. This AF gauge will be hooked up to an output of a wideband which will make it accurate. I'm just worried about the response time which isn't the reason why people don't recommend regular A/F gauges. People don't use A/F gauges because when hooked up to narrowband sensors they do not display correctly since the narrowband voltage is not linear in relation to air fuel.

BXR, that gauge would be PERFECT for me but I can't use it. First off it is a little pricey at $198. second, I'm not using an FJO and I've been told that the new gauge only accepts signals from a special FJO cable. I will be using a programmable 0-5v output on the wideband to make the A/F gauge work so the gauge isn't compatable.

I am just concerned with the reaction times of conventional A/F gauges. I don't see how there could be much of a difference when measuring a simple voltage but maybe someone can explain to me if and how there is such a difference.
 

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i do believe that greddy has an a/f gauge i would assume its better than autometer
 

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Discussion Starter · #8 ·
I've seen the Greddy kit that comes with an O2 sensor and costs $300. What I'm looking for is a cheap gauge that will warn me if I am running dangerously lean. I am in no way trying to tune with this gauge I am just using it as a warning light. I'm just worried that by the time the gauge hits red it will be too late...
 

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I honesty, by the time you'd see the warning light in the cheaper guages, you'd already be punching holes through pistons. The Autometers aren't very good, and after having owned the Greddy kit, I'd say it isn't much better. It took a second for the guage to catch up with the actions taking place on the pedal. Not good. The FJO was leaps and bounds ahead of both in reaction time and in ease of seeing the display. As soon as I touch the pedal, the FJO registers it. No guesswork involved.

Eric

4 digit HP
 

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VeilsideTT said:
I've seen the Greddy kit that comes with an O2 sensor and costs $300. What I'm looking for is a cheap gauge that will warn me if I am running dangerously lean. I am in no way trying to tune with this gauge I am just using it as a warning light. I'm just worried that by the time the gauge hits red it will be too late...
Please don't waste your money on the $300 Greddy one. It uses a narrowband sensor, and once you've run it WOT a few times the sensor gets saturated and turns into a "Rich" "Lean" gauge. I had one in my WRX, broke it in properly, and headed to the dyno. First pull, Greddy showed a healthy 11.5:1 (Cause that's why I had tuned it to on the street), dyno's wideband showed 13.5:1!!!! Now granted, the dyno's wideband was further downstream, I would expect maybe 1/2 an AFR point off, but nonetheless, coulda popped a motor @ 13:1 even. Save up for a real wideband, cal it against another known good one, IE: Dyno, and go out and have some fun. If there is anything you shouldn't go cheap on it's this.


Ryan
 

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VeilsideTT said:
I posted a similair question in the shop and parts review section but nobody has answered it and I'm looking to get a gauge very soon. Since the display on my WB is pretty small I plan on hooking this AF gauge up to a programmable output on the WB so I have a big red light if I start running lean.

I was just wondering if some gauges react slower than others and if so, which are the fastest reacting gauges? I was going to buy a cheapo Autometer but somebody told me they were very slow to react. Could there really be a huge diffeence in reaction time for a gauge that is only measuring a simple 0-1v charge?
The Autometer AFR meter was designed to work with a narrow band o2 sensor. The narrow band o2 sensors are slower to react than the WBo2 sensors. With that being said, I can get you a converter that takes the Bosch wide band oxygen sensor and translates the output to read on the Autometer AFR meters. The display on the Autometer AFR meters is very quick to react.

Here is a pic of the converter.Converter. It is at the bottom of the page.
 

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VeilsideTT said:
Magic, I would but the new Innovate unit is completely digital, has more features, is just as accurate, has 44 minutes of datalogging and is half the price. I have already ordered the unit so I'm hoping it lives up to its very good initial reviews.
Where did you get that wideband unit?
 

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I was looking into an Autometer A/F gauge as well, but I was told you're are much better off getting an Exhaust Gas Temp gauge.
Autometer A/F gauge isn't a wideband, and consequently is useless for tuning. It can only indicate whether the mixture is richer-than 14.7:1 or leaner-than 14.7:1. It can't tell you accurately what the actual mixture is.

EGT gauges are practically useless as well for AFR tuning. Much more detail on this is available in the FAQ section of www.widebando2.com

With an EGT gauge, you can monitor temps and catch them as they are rising.
Unfortunately, EGT gauges such as GReddy, HKS, Apex, etc., react VERY slowly. By the time they read 900 C, you've already been at that EGT for a few seconds. EGTs increase or decrease INSTANTLY when you make a boost/throttle position/ignition timing/engine load/etc. change. The delay that you see on the gauge is a result of the slow reaction time of the gauge, not a true indicator of how long it takes EGTs to change.

I used to have a Heraeus system with open-element sensors on each header runner, as well as a GReddy gauge with the probe in the header collector. The open element sensors were very quick-reacting, but the GReddy would take several more seconds to read the same temperature. For example, I could stab the throttle in 2nd gear and within about 2 seconds the Heraeus system would go from 500 C to about 850 C, an increase of 350 C. During the same period, the GReddy gauge would only increase the temperature indicated by about 175 C.

This Heraeus system with fast-reacting probes on each runner, peak hold, data-logging, and solution trigger STILL was unable to give any useful tuning information (other than to somewhat verify that the cylinders were all running at about the same temperature. Compared to the FJO wideband, this elaborate $1750 EGT monitoring system was worthless as a tuning tool.

Steve Hayes
 

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Discussion Starter · #14 ·
Ok guys, there seems to be a little confusion. I know that A/F gauges are normally worthless because they work with the non-linear, slow reacting sensors. I will be connecting this gauge to a programmable output on my wideband though. This means that the output on the WB is just taking the AFs and converting them into a 0-1v signal for the gauge to display. I will be able to program when and at what voltage makes each individual light on the gauge go off. So this gauge will be used with a wideband sensor. Taffy, thanks for the offer but the wideband I bought already comes with 2 of those outputs (converters) you are talking about.

Cowboy, I am curious if you ran the Autometer with a narrowband or wideband sensor. I am curious to find out whether these gauges are slow to react because of the sensors they are normally used with or because the gauges themselves are just slow to react. I have a hard time believing that one voltometer that has an LED display (thats what the autometer is) can be so much slower than another... I don't want to make a $2000 assumption though. Could the Autometer be so slow at recieving a voltage from the wideband and lighting up a corresponding LED?

Axoman, go to www.innovatemotorsports.com. You can also check out the turbo mustang boards and http://forums.nasioc.com/forums/showthread.php?s=&threadid=393330. They have had some experience with the unit and seem to have great things to say about it. Innovate has also started a Yahoo group for tech support and general questions so you could check that out too.
 

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I have been looking at this gauge and will probably end up with it. It can be connected to the 0-1v (narrowband) on my AEM UEGO wideband O2 sensor. It should read the same as the AF as my AEM display, and has a programmable signal to indicate lean conditions.

My only concern is that lean numbers happen all the time (decelerating, and low load conditions). I guess I can wire a relay from an AEM output to only allow the signal when engine load is greater than 150kPA absolute (7.1 psi).



http://www.nordskogperformance.net/m9200.html
 

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Based on the fuel to AFR table this will not work with the AEM. But it may work for other applications. Here is the table I got from Nordskog.

Code:
GAUGE READING	AIR/FUEL RATIO
0	17.0:1
0.1	17.0:1
0.2	16.0:1
0.3	15.5:1
0.4	15.0:1
0.47	14.7.0:1
0.6	14.6:1
0.7	14.5:1
0.8	14.2:1
0.875	13.5:1
0.9	13.2:1
1	12.5:1
 

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Discussion Starter · #17 · (Edited)
Yeah, seems like a good display but the numbers are just off. :(

Still curious about the autometer and similar gauges though...

Also, has anyone had any experience with the Stewart-Warner gauges?
 

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what other reasonably priced gauges aside from greddys use electronic 0-5v senders? their oil and fuel pressure and probably boost pressure ones most likely do. it would be damn cool to have a wideband a/f gauge with peak/hold and a needle instead of LEDs... if you wouldn't mind having my a/f referred to in kg/cm^2

i don't think there is any delay built into autometer type a/f gauges. i would try to get a gauge with more LEDs. your 0-1v output on the innovate should work fine with these, you can leave the output linear instead of trying to mimic a narrow-band output and it should work fine. here is a link to how these things (or how the one chip most likely) works:
http://www.scirocco.org/tech/misc/afgauge/af.html

if voltage is within a certain range, an LED/bar lights up.

shiva
 

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shiva said:
what other reasonably priced gauges aside from greddys use electronic 0-5v senders? their oil and fuel pressure and probably boost pressure ones most likely do. it would be damn cool to have a wideband a/f gauge with peak/hold and a needle instead of LEDs... if you wouldn't mind having my a/f referred to in kg/cm^2
Why would you want peak hold on a A/F gauge. It varies so much from idle to WOT to 0% throttle (super lean). I would think that a long playback would be nice.
 

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I wouldn't get an Autometer one, a friend dynoed his and the readings were up to 2 points LOWER than what was the actual reading from the computer.
 
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