openecu.org

Is ecuExplorer capable of logging boost up to 18.427 psi only?

18.427 PSI is 1.27Bar - this is the limit of the stock sensor on the car that reads MANIFOLD RELATIVE PRESSURE.

the MANIFOLD ABSOLUTE PRESSURE will read much higher than 1.27Bar but it is absolute so it includes ATMOSPHERIC PRESSURE too.

that is why i created the user-defined data item MANIFOLD RELATIVE PRESSURE (CORRECTED). activate this data item and it will use the absolute pressure value and automatically subtract the atmospheric value from it, which will then give you the boost values you're looking for.

calvin.

Where does manifold absolute pressure come from? I thought the 18.47 psig limitation was a physical limitation of the sensor. AFAIK, there is only one manifold pressure sensor and one atmospheric pressure sensor (on the ECU board itself)

Freon wrote:Where does manifold absolute pressure come from? I thought the 18.47 psig limitation was a physical limitation of the sensor. AFAIK, there is only one manifold pressure sensor and one atmospheric pressure sensor (on the ECU board itself)

Manifold Absolute Pressure (MAP) comes from the MAP sensor (located on the manifold).

Manifold Relative Pressure (MRP) is a calculated relative pressure, based on MAP signal + Atm Pressure signal (located on the ECU board as you mentionned).

The first one is limited to 2.55 bar readings, the second one is limited to 1.27 bar readings on most Ecu's (not all of them, though).