The Basics: Boost Introduction: Here at Treadstone one of our main goals is to educate our customers to provide them with the knowledge to safely boost any vehicle they desire. This is why we have decided to introduce “the basics,” which will be a series of blogs that will present information in a simple to understand format with liberal use of lamens terms. Today we will cover the topic of Boost as always we will cover some definitions first. Boost is defined by the pressure in the intake manifold above ambient air pressure aka (the actual pressure above ambient). i.e. A naturally aspirated engine at sea level actually sees 14.7 pound of air pressure in sharp contrast, a turbo charged car running 10 psi actually sees an Absolute Air Pressure of 24.7 psi (14.7psi + 10psi) at the same sea level. Moreover the ambient air pressure is dependent on weather and your location’s elevation, so it changes from hour to hour and from vertical distance travel. As a result, you should always use absolute pressure, to measure boost pressure. Another example, at sea level, on a day with an ambient air pressure of about 14.7psi, boost is anything above 14.7psi. A value of 14.7 psi would represent a boost pressure of about 1 bar, or 200 kPs. However, in Calgary, Alberta, Canada, at an elevation of 3750 feet, the same 200 kPa is on top of a typical ambient air pressure of 90 kPa, for a boost of 16 psi. If a low pressure front had passed through, the same kPa might be even more 'boost'. But the pressure inside the engine is that same in all cases. As a result, absolute pressure in kPa is a better measure of how much the engine is working than 'boost' values.