First, I assume you have read the Wiki section on MAP calibration
5peedmanual wrote: ↑Sat Mar 04, 2023 4:38 pmHow can I calibrate this at 0V?
If your sensor is one of the numbers listed in TunerStudio pressure sensor calibration, it is already calculated for minimum and maximum pressure reference to voltage. If your part number is not listed, you can do two or more things:
- Use the datasheets for your sensor and calculate the transfer function 0V and 5V pressures to enter into calibration as a custom calibration
- Check similar sensors for the same transfer function values, and if it matches perfectly (sometimes), just use that provided calibration
Remember, the calibration uses the pressure at 0V and 5V, not the voltage at 0kPa and max reading. Most sensors cannot read to 0kPa. If testing accuracy, use the functional results, e.g., atmo kPa (current barometric pressure), against current conditions at your location. A more accurate test of your location will require more accurate test equipment, so you are not testing against junk (like a cell phone sensor).
5peedmanual wrote: ↑Sat Mar 04, 2023 4:38 pmsince its not atmospheric pressure, and I can I know how many kpa is at max acceleration? Can I calculate it with engine cc etc?
The sensor reads atmospheric pressure at power-up, or at intervals if real-time baro option is used. TunerStudio calculates the engine displacement with other factors to produce an estimate for the VE Table, but due to other factors and errors, is not a true representation of volumetric efficiency of cylinder filling.
As barometric pressure (atmo) varies, and VE is relative based on many other factors such as air filter restrictions, exhaust efficiency or state of tune; it is difficult if not impossible to predict accurate kPa at max acceleration. Fortunately, the actual MAP kPa is reported and logged (if desired) for any conditions, including max acceleration. These actual results are then used as references in tuning. We want calibration, but do not want to "zero", as the values are relative to current actual.
I hope I understand your questions and helped to answer them. If not, please be more specific, or provide the purpose of the exercise. There are often different ways to approach info or solutions.