Finding the proper offset and slope for your wideband, fuel pressure gauge, or other analog input can be tedious. Here is a simple spreadsheet we use in house to calibrate anything we plan on logging with HPtuners EIO. This simple spreadsheet will help you calibrate a wideband, fuel pressure gauge, etc. The input must be linear which means it follows a straight line; y=mx+b. To setup a wide band I recommend displaying raw voltage in the table display. You then will want to match up the displayed value on your wideband with raw voltage as read by HPtuners. I recommend doing this any time you want to get data as accessories, car chargers, battery condition, system voltage, etc can all skew ground offset and slope.
1. Hook up your HPtuners EIO/Aux input – See HPtuners help file
2. Instead of logging the predefined input log voltage
3. Start car, if possible run the AFR rich and immediately shut car back off. Continue to log!
4. Watch your wideband/fuel pressure/etc. guage. Note two datapoints. For example: 2.345v = 14.65 AFR; 4.653v = 11.32 AFR.
5. Input these two datapoints into the excel worksheet.
6. Copy the new function into your Aux Input List- User Defined – Configure User Defined Window.
7. Add User defined pid to your table display and enjoy accurate logging!