Why difference in Voltage for AFR on Page 8 of LC-1

[Teutonic Speedracer]

The LC-1 install guide shows the PID being setup for 10:1 to 20:1 corresponding with 0.00 to 5.00 Volts. Then the AD*3+7.35. Why does it tell you to program the LC-1 for .88333 to 4.21667?

Can someone please explain?

[joecar]

The two points are: (0.88333, 10) and (4.21667, 20)

The slope is: m = (20-10)/(4.21667-0.88333) = 10.0/3.333 = 3.000

The equation is: afr = (v - 0.88333) * 3.000 + 10

simplifying this: afr = (v * 3.00) - 2.65 + 10 = 3 * v + 7.35 which is what the calc pid is.

[Teutonic Speedracer]

Thanks! That

[Teutonic Speedracer]

Thanks! That makes much more sense!