The amount of air pressure above normal atmospheric pressure that a turbocharger or supercharger forces into an engine's intake manifold. Measured in pounds per square inch (psi) or bar, higher pressure pushes more oxygen into the cylinders, allowing the engine to burn more fuel and generate significantly more power.
We're losing about three pounds of boost somewhere, so check all the intercooler piping for a loose clamp.
A sudden loss of boost under load usually points to a blown charge pipe or a failing wastegate actuator.
Also heard as
- manifold pressure
- charge pressure
Related terms
Forced induction
The process of compressing intake air to increase the power output of an internal combustion engine.
Supercharger
A mechanically driven air compressor that forces extra air into an engine.
Wastegate
A pneumatic or electronic valve that limits turbocharger boost pressure by bypassing exhaust gases.
Intercooler
A heat exchanger used to cool compressed air from a turbocharger or supercharger before it enters the engine.