How Does a Boost Gauge Work?
Whether fitted with a turbocharger, a supercharger or both, the bottom line is that the vehicle’s engine relies on a steady and very controlled injection of compressed air.
The boost gauge measures the pressure of that air, as it enters the combustion chamber. To achieve this, a special tube is attached to the intake manifold of the engine, and this will gather a tiny amount of the incoming air and present it to the gauge, located on the dashboard. The internal components of a mechanical boost gauge center around a Bourdon tube, which inflates and stiffens as the incoming pressurized air meets it. As this happens the tube moves a link, which in turn activates a pointer through a series of cogs and springs to indicate the associated pressure on the screen of the device. However, some vehicles are fitted with a digital boost gauge that’s meant to electronically measure the boost provided, by monitoring the air compressor and providing an estimate of the output to the gauge. This indicates the number of bars of pressure, or the pounds per square inch.