I recently purchased HP Tuners along with a FAST Dual Sensor Wideband.
After reading the instructions of both, I was very confused on how to configure the linear equation using the EIO input.
What was creating my confusion was not knowing the controller's AFR range.
I called FAST and was told 9.6 AFR to 20.986 AFR.
The instructions indicate that the meter reads up to 4.096 volts.
Now, let's get to the fun part of this post, the mathematics...
Equation 1 (this is how the FAST Wideband interprets the voltage) - (Input Voltage from O2 sensor x 2.78) + minimum AFR range(my case being 9.6)
Example 1: (2 volts x 2.78) + 9.6volts = 15.16 AFR
Equation 2 (this is used with HP Tuners) -
Output Voltage Range = 4.096
AFR Range = 20.986 - 9.6 = 11.386
Minimum AFR Range = 9.6
(Input Voltage from O2 sensor/(4.096/11.386)) + 9.6
Example 1: (2 volts/(4.096/11.386)) + 9.6 volts = 15.159571 AFR
I entered in .3597 in the blank under input volts and 9.6 in the + blank.
Both of these formulas equate to almost the same result.
I hope this post will help others.
Please correct any misinformation that I have left, gurus!
I am going out on a limb here.
Thanks for a great product!