AEM 30-4100 setting for m4

[mr2daj]

I have already asked for the settings for an lc-1 and was told it was not ideal. I also have an AEM 30-4100 and i understand this will be better. What program do i need to put the aem into and what if anything do i need to do in the m4 software? From what i can tell i need to use p3 as this is 0.013v to 0.425v.... any help much appreciated.

Thanks, Dan

[mr2daj]

anyone?

[mr2daj]

double post

[Holmz]

You could use an OP-Amp and change the range of the 0-0.4V to a new range which is higher...
Basically this is a voltage diver in reverse, which is called a voltage multiplier, or more commonly an amplifier.

[AdamW]

The M4 has reasonable resolution on its lambda input channel so you should be fine with the AEM set to P3 mode. However, you will need to use the custom lambda calibration table in the Motec which gets a little more involved. Also to make things trickier, I think the help file (F1) in the Motec lambda calibration page has a mistake – the help note suggests it is a 5v input with a 10bit resolution whereas I’m very sure it is only a 1v or 1.2V input (still with the full 10bit resolution).
To give you some understanding of how it works:
Your analog lambda signal is connected to the Motec Lambda input – inside the Motec this input is a 10bit analog to digital converter. The ADC converts the analog voltage into a digital “number” for communication to the Main processor. 10bit resolution means the ADC can output a digital number from 0 to 1024. So (assuming it is actually a 1v input), when you input a voltage of 0v, the ADC will communicate a digital value of 0 and if you input a 1v signal the ADC will communicate a digital value of 1024.
When working with the M4 Lambda cal table you have to work in these digital values rather than actual volts.

According to the AEM data sheet your gauge will output 0.013v @ 0.7Lambda and 0.413v @ 1.25Lambda, so we first need to convert these voltages into digital values: 0.013v x 1024 = 13
0.413v x 1024 = 423

Set your Lambda mode to -1(user defined) in the Motec sensor setup page, then go to the Lambda cal table and in the “70” cell (for 0.7Lambda) you enter your digital value of 13 (put 13 in all cells below 70 also). In the “125” cell (for 1.25Lambda) enter your digital value of 423 (enter 423 in all cells above 125 also). Once you have those 2 values entered you can hit F9 to bring up the function menu and use the “horizontal interpolate” to fill in the other cells. Here’s a couple of screen shots to show how that table should look:



Hopefully, that will work for you, if not then you will just need to tweak this cal table until the values displayed on your Gauge match those displayed in the Motec software. If you get stumped, post back and I will try to help.

[AdamW]

Sorry, this forum cuts off the image rather than scaling - if you right click and "save image as" you will be able to see the full picture.

[mr2daj]

You my sir are an absolute legend. Thanks so much for your help. i will get onto that when i get 5 mins and see how it goes.

Dan