I connected my AEM afr gauge to the AN1 socket of the Datalogit beige box but when I open monitor box in datalogit software the afr values showing are totally different to the ones in my afr gauge, eg. 14.1 on aem, 4.0 on datalogit.

I tried 0 = 5, 5 = 20 and tried entering some numbers I found in the forum into POLY box but still can't see the correct afr values.

I have either done something wrong with the connection (single wire from AEM to AN1) or done something wrong with settings in Datalogit. I would appreciate some help as I urgently need to take healthy logs before tuning early next week.

 

You put those into the Setup Auxiliary AN1? Did you Setup Chart and Window Add Watch ? I just use the single AEM wire to the AN1. And in the Setup Auxiliary I use 0=9.7 5=19.7 to get the AFR the same or very close to the same as on the gauge.

 

Yes I put those into setup auxiliary AN1. I tried 0 = 9.7 and 5 = 19.7 as well as 0 = 5 and 5 = 20. Still no luck. Below are some screenshots I'm probably missing something:

 

How about Setup Chart? And you should have a max value 20 in the Setup Watch

 

is this it?

 

On the chart with red line the values seem correct but shouldn't we be seeing the same values in monitor section on the top right box next to AN1?

 

Ya the chart looks right, try changing Num to Avg for that map watch. How about add watch for a little tiny window to display Afr

 

That monitor window displays only the voltage for AN1

 

Hey thanks, it works now and I really appreciate the help. I added watch box for AFR but seems laggy, and only displaying full numbers without .00 values is there a way to speed it up?

 

You're welcome. close out the little Afr window and try again, add watch and you can select 1 or 2 decimal places and the more you have checked to data log in the monitor window the slower and less data per second everything records, I usually data log everything but the sensors.

 

In setup chart I set it up to just show Afr between 10 and 16 to get a better look, and I add lots of other stuff to the chart, and lots of little add watch boxes for everything

 

Ok, cool. I will play around with settings and charts tomorrow. Btw the difference between 0=10, 5=20 and 0=9.7, 5=19.7 is minimal but I think latter one is closer to the values displayed on the gauge.

 

The following applies to WBs with their own AFR meter.

What most people miss or do not know about: the logged AFR can be .1 - .3 AFR off what the wide band's own meter displays.

Put the sensor in a sealed jar and fill with some type of gas vapor to expel the oxygen. Do so to the meter shows about 11 AFR. Log and look at the displayed laptop AFR value. Then adjust the AUX setup values so it now logs what the wb says.

Kyle and I discovered this problem back in 1999 when on a Porsche race shop dyno, we leaned that are expensive Aussie wb without a meter was logging .3 leaner than the shop's system.

Then with units with their own meter, we saw the same problem.
This is how you calibrate your WB--> datalogit-->laptop to record most accurately.

 

^^ Thanks for this, now I know why I couldn't get them to display the same values but didn't worry about it too much either .1 to .3 won't make a difference if the tuning is on the safe side.

 

The two widebands I have used also have their own dataloggers so you can also just compare the two different datalogs. And ya as long as it's within .1 it shouldn't really matter. My experience at dynojets is their wb readings were extremely different and more rich and shouldn't be trusted or tuned with.