(First post!) The other day I was using my OBD-2 scanner and found out that my car's intake has a peek flow of 25 lbs/min. I converted this to ~317 cubic feet (at 5.5 deg C) I then calculated the velocity in the 3.5" diameter intake to be ~36 feet/sec. The intake has a 2" venturi orifice (sound muffler) and calculated the flow at this point to be ~64 feet/sec. Here is where I am stuck. How do I calculate the pressure difference? Thank you in advance!