Originally Posted by rotarymike

Subbed. This is interesting stuff - did similar with old Pic Micros and sensors in the early aughts to make data recorders for the racecar. FWIW, the pc-board mount pressure/vac sensors used in the old Megasquirt standalone ECUs were inexpensive and very accurate, but they had to not be in the engine bay, or very well shielded from heat. Our experience using electronic gauge sensors and OEM MAP sensors from various cars showed they had a built-in time filter - that is, they reacted very slowly in electronic terms to changes in the measured pressure. For measuring cylinder pressure rapidly we ended up using a lab-grade stainless sensor that cost hundreds - thank goodness we only needed one.

For this project, I'd like to see if passing the PCV through a oil/air separator (basically, the drain bottles everyone is using with some steel wool added) then back to the intake changes the pressures and performance substantially.

Pressure v. RPM and engine load (I guess derived from injector PW) would be interesting to see plotted out.