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Need Some Help

i had to do some work on my car. i have a autometer afr guage that runs on 4 volts not 5 like a trinity.


I had this set up right.. well it got messed up.. i had them walk me thru what the parameters was HIGH AND LOW so the numbers on the guage matched what was showing on the trinity..  like a idiot i was in a hurry and didn't write this down.  


well i called them again.. and i can't get them to tell me what HIGH AND LOW numbers i need to set the guage to so it show the readings on the trinity correctly.


what i did get was the college 4.0 student major in brain surgery answer.


take a look and if anyone knows what this needs to be or can help would greatly be appriciated






I have copied a very useful reference below that will give you some information about using our wideband with other ECU's that are looking for a 0-5v signal. Let me know if I can assist you further with setting it up. You should see a 0-4v output from the Auto Meter gauge. If the gauge does not output 4v at full lean (you can test this with the sensor in open air) then we would want to see the gauge in our service department.


The formula to determine the AFR output from the voltage provided by the gauge is derived from y=mx+b (algebraic equation for a straight line), where in our needs the following applies:


y = AFR

m = slope of the plotted line (BGD AFR High - BGD AFR Low ) / (4v - 0v) x = output voltage from the gauge b = offset or AFR value at 0v


Using the default values of 10:1 AFR for 0v and 16:1 AFR at 4v the formula looks like this:


y = ((6/4) * v) + 10


or can be simplified as:


y= 1.5*v+10


If we plug in 1.25v into that equation then we get: 11.875:1 AFR = (1.5*1.25) +10 which falls right along the plot chart. If you need a 5v 'input' for the Diablosport, you would get 17.5:1 AFR for a theoretical 5v signal.


If you were to adjust the BGD endpoints to say 11:1 and 15:1 then the formula would be modified to look as follows:


y = ((4/4)*v+11 simplified to y=1*v+11 or y=v+11




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for anyone that has a autometer afr guage or going to get one.  


10. low

16.0 high is the settings so it reads correctly on the trinity


no math equations.. just changed the high number till the trinity read the same as the guage.. good bad wrong whatever.. it is what it is.

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