Discussion and questions related to the course **EFI Tuning Fundamentals**

It's a fair question. I've gone into this in a little more detail in the about to be released reshoot of this course but here's the reason:

The equation for air density is: Density = Pressure / R x T

R is the specific gas constant which equals 53.35 so this ends up on the bottom of the equation. P for this example is measured in pounds per square inch, but we need to change this to units of square feet since we're calculating air density in pounds per square foot. To convert from square inches to square feet, we need to multiply by 144 since there are 144 square inches in a square foot.

So forgetting about temp and pressure for a moment we end up with 144 / 53.25 which is equal to 2.7. This gives us the constant of 2.7 in the equation :)