So I am looking into getting an a/f gauge for some tuning purposes. I know of two so far, the defi 52mm (150.00) or the AEM UEGO 52mm (440.00). My question is, why the big price swing, difference, etc. I would like one that reads accurate and that can run at all times. It seems that some are divided on running the AEM at all times, and I haven't seen anything on the DEFI gauge. Any input??

 

Defi plugs into the ECU and reads from there which is not very accurate unlike AEM that actually measures the AF.
Defi gauge is more of a bling.

 

the AEM is a Wideband O2 sensor and controller package.. The other gauges tap into the stock narrowband O2 sensor.. The difference is accuracy, additionally many of the wideband setups can also log or display the data on a computer to aid in tuning the car.

 

Ok so far this is true:

DEFI = "Bling" but some sort of display
AEM = Accurate and loggable maybe

150 or 440 hmm.... I just spent 780 for defi 60's b/f, and now it seems that 440 is my next deduction. Any other input????

 

wow, thats alot for an AF guage..... is the defi one that inaccurate?

-Shahul

 

what he said

 

the gauge itself is only as accurate as the O2 sensor already in our cars.. since its a 1.0v range, (A wideband has a 5.0 range) plus there are only a few 10ths of a volt that are useful in wide open throttle operation, its certainly not as responsive or informative as a wideband. Anything is better than nothing, but don't expect to be able to tune adequately with a A/F gauge that taps into the stock sensor.

There are a few cars out there that actually do have wideband O2 sensors, ours isn't one of them though.

If your going to spend your money on another Defi Gauge, get the EGT gauge.. Its another useful tuning tool and at least its pretty accurate.

 

it depends on your use for the gauge, and your overall plans for the car.

If your plan is to ahve the basic bolt ons most people do (exhaust, intake, boost control, maybe a reflashed ecu and pssibly some cams), tehn the Defi si more than adequate IMHO - it gives you a geenral ida as to what is going on, is easy to read, and matches the stock gauges nicely. It use ths signal from your stock 02 sensor to give its readings.

the AEM one is great for the guy stepping it up to some form of user tunable engine mgmt (UTEC, Power FC, AEM, etc). It include a wideband 02 sensor which needs to ahve the bing welded into your exhaust pipe. On its own, it does not log any data - it can be hooked up to some dataloggers, or used with any standalone system that supports a wideband output.

if you are loking into a unit that can log data as well as show it on a real time display, something like the Turbo XS tuner would be worth looking into. Just realize though that at this point you are talking about nearly 6 times the cost of the Defi unit and about l5 times the cost of the AEM unit - yes it does alot more than either as well, but if you cannot realstically make use of it, its not money well spent IMHO.

Adam

 

Let me be more specific as to why I am looking into an a/f gauge. I have the afc2 and want to tune it based off of the a/f ratio and not a knock signal. I can't begin to understand why apexi created this without an input from an 02 sensor, either wide or narrowband, but I want to utilize the unit to it's fullest. Right now only bolts ons are in the future for me, but I have said that before and ended up with a "race only" vehicle. I don't plan for "race only" with the evo, but I could come close to that if the circumstances were right. Anyway, it seems that the AEM is the way to go, so thanks for the input. But.... if anyone knows of a cheaper wideband o2 meter, drop me a line so I can do some research on it. Thanks.

 

Check out PLX devices at http://www.plxdevices.com/index.htm

They have some cool products and can save you some money (prices start at $329). Check out the wireless wideband with data logging. It isn't cheaper than the AEM at $499, but gives you more of what it sounds like you want.

 

Well, I don't know about cheaper, but another option is innovate motorsport's wideband kit:

click

 

The Innovative and PLX are both really nice kits- very complete.

IIRC you can moniter 02 voltage (narrowband) on the AFC2 in the same way you did on the last gen AFC (with the blue screen and without knock monitering). The SAFC's cannot take a wideband input though

 

And this is why I was looking into getting an a/f gauge. I can't understand why the SAFCII didn't think of incorporating some sort of o2 sensor input into the unit. I understand that it would probably cost more, but come on, why tune off of a knock signal. By that time, you could have already done damage, and if you are running rich you won't get any variation. In short, I spoke with Paul at PLX and his system seems to be the way to go. Plus it is only 4 1/2" x 2 5/8" x 1"

 

What I have in my car. Works great.

http://www.techedge.com.au/vehicle/wbo2/default.htm

 

As I said you CAN moniter 02 sensor voltage on a SAFC2 - it can only do it narrowband signal though.