With the AEM analog wideband (part #30-5130) AEM's wideband/AFR gauges have come a long way. They released the original AEM UEGO with the red digital display about five years ago, and it was hunk of crap and completely useless for datalogging. Besides a high rate of manufacturing defects, even a working unit had had electrical noise problems for the analog signal and the voltage range was not truly linear. A couple years ago AEM revised the digital models, which now have a 0-5v AFR reading. The analog signal is still susceptible to electrical noise and won't fully agree with the display, even if you run a common ground to the Datalogit AN2 wire.

The AEM analog gauge appears to have finally fixed both the voltage range and the quality of the signal. It is designed to run with a signal wire and a floating ground wire. I just got to mess with one of these and it seems to work well. I am linking to two diagrams to help with setting it up.

Diagram 1:



Diagram 2:



The first diagram is the wiring. A white and brown wire comes off the main wideband harness. There is no blue serial wire like on the older models. The white wire should go to AN1 and the brown wire should go to AN2. The second shot shows how to set up the DL auxiliary input screen using the data provided by AEM. Click the "Poly" button and set the values as shown in the screenshot. Just FYI, AEM listed the transfer function as AFR = 2.375(V) + 7.3125

After that you should be good to go. It's not a digital display so therefore not as precise to read, but from what I can tell the gauge and the Datalogit seem to agree closely enough. The cool thing about an analog wideband is that you don't have to worry about a choppy display.

Hope this helps,

Raymond

 

why wasnt this stickied?

 

Because each WB maker includes wiring instructions that most people who are somewhat electronics capable can understand.
The DataLogit DELTA function shown is not always the best way to do it either.
And you need to actually calibrate your laptob DL logging to the WB unit's meter else it can be .1 to .3 AFR off.

All from 10+years experience.

 

i assumed since this seems to be a common problem with the aem wbo2 not graphing properly it would have been important to let people know the newer unit can work. but either way i guess

 

"AFR = 2.375(V) + 7.3125"

does this apply for the 2009 models of the digital ones?

 

No. The instructions for the digital display ones don't directly give a transfer function. However, the AFR vs voltage chart says that 0 volts is 10:1 AFR and 4.25 volts is 18.5:1 AFR, with a linear sweep. According to the DL the result would be a transfer function of AFR = 2.0(V) + 10

This is assuming that the rotary switch on the back is in the default P1 position.

 

sick man.. your like a pool of information i love it! thank you soo much

 

Hey Cewrx7r1 what do you do to calibrate the laptop? Just read the signal in a steady condition and adjust the x-fer function offset to match, or do you use another method?

Unless you need the extra channels why would you not use the delta function on the datalogit? or do you just mean it is not 100% relaible without also calibrating the analog in reading as well?

Thanks

 

it's all in the instructions bro. you just have to know where to look and how to interpret what you are reading.

 

When I tried the DELTA function on mine, it was inconsistent and way off the WB's meter even with the suggested WB AUX setup. The problem is too many floating grounds.

My cure was to connect my wideband ground lead to a Datalogit ground lead that I installed in the DL box to its circuit ground, and put a noise filtering capacitor across the WB + lead to the new DL ground.

To calibrate, I put the O2 sensor in a sealed jar with a propane/air mixture to make the WB's own meter show near to 11 AFR. Then adjust the AUX setup values so that the DL records within .05 AFR. The best way is very expensive, using calibrated gases.

 

in my experience the accuracy of the signal varies significantly with different widebands and different wiring configurations. what works best for one wideband doesn't necessarily work best for another.