avp23;991273 said:
so when im boosting im forcing millimeters of mercury inside my motor? :1zhelp:
Lmao. MM/hg is simply pressure expressed by using a column of mercury to measure it. Gases have mass and are therefore subject to the force of gravity. The weight of our atmosphere pressing down upon us will, at sea level and 59 F, push a column of mercury 760 millimeters up a tube. Mercury is used because of it's density. If water was used the tube would have to be 33 feet tall.
In engineering 760 mm/hg is expressed as Torr, therefore 760 Torr also equals one atmosphere, as does many other units. 760 mm/hg also happens to be 29.92 inches of mercury, what barometers (in the USA at least) display. In this country it's most commonly used by meteorologists, the public, and in aviation.
The same force exerts 14.7 psi. In other words if you could hold a vertical column of the atmosphere 1 inch square in your hand it'd weigh 14.7 pounds. If you're of average build your body is holding off about 20 tons of pressure as you read this. I'll leave it for you to figure out why you haven't been crushed...