You are ok with 4V max.
Here is the formula From SCT
This is the start of the Formula: (Volts*X)+Y
We take the A/F equal to 0 volts to figure out the Y.
We take the A/F equal to Max Volts to Figure out the X.
Here is an Example:
(V*X)+Y
0 Volts = 10/1 AFR. Lets Call this Value1
5 Volts = 18/1 AFR. Lets Call this Value2
(V*1.6)+10
To Figure Out Y: Y is always equal to Value1, so Y=10 in this example.
To Figure Out X: Take Value2 (18 in this example) and Minus Value1. So 1810=8 in this
example. Then divide that number by the max volts. (5 in this example). 8/5=1.6.
Here is another Example:
(V*X)+Y
0 Volts = 10/1 AFR. Lets Call this Value1
5 Volts = 20/1 AFR. Lets Call this Value2
(V*2)+10
To do your gauge you need to set or know what the AFR is at 0V and 4V and you should be all set. If you know what they are post it and I'll help you with the formula.
Paul
