Data Analysis: RPM vs Oil Pressure vs Oil Temp

[MotorvateDIY]

I have started to spend a little time looking at the data the LCD gauges / Mini-dash have been recording to SD from the CAN bus and the Bluetooth sensor server.

Here is a plot of engine RPM vs engine oil pressure vs engine oil temperature during an easy drive with a few wide open throttle and 7,000 RPM shifts.

In looking at the graph, you can see a few straight lines.
Engine oil pressure is a linear (aka straight line) function of oil temperature and engine RPM.

Around 90 PSI the graphed data starts to bend to the right. This is when the oil pump bypass valve starts to open, to prevent excessive oil pressure.




If you look at the small circle at the bottom left, that shows that my engine has 16 PSI at 654 RPM when the engine oil temp is 95C / 203F (data panel is in the top left)

That means my galley gaskets are still good 🙂

[Z34Life]

How are you managing to get oil pressure data to your LCD dash? I am guessing you have an aftermarket Oil Pressure sensor? what are you connecting it to? ( I ask the question because normally it's connected to a gauge of some sort directly).

"started to spend a little time looking at the data the LCD gauges / Mini-dash have been recording to SD from the CAN bus and the Bluetooth sensor server".

maybe I am not understanding this correctly?

[MotorvateDIY]

I replaced the oil pressure switch with a 150 PSI oil pressure sensor.
The oil pressure sensor is connected to our "Bluetooth Sensor Server" and sends the oil pressure values to our LCD gauges / mini-dash.

The Bluetooth Sensor Server supports up to 8 analog inputs. Right now it sends oil pressure, fuel pressure, manual transmission oil temp and differential oil temp.

The LCD gauges / mini-dash is connected to the vehicle CAN bus to get engine RPM, engine oil temp and 30+ other items.


Bluetooth Sensor Server Overview:
https://youtu.be/U_kH3K_C2AE

Mini-dash / LCD Gauges Overview:
https://youtu.be/lndZiRxDNOo