Boost Gauge question

[Willie Two]

I've searched the forums looking for an answer(s) without luck, Technically speaking what is the boost gauge measuring ? the turbo output ? How is that reading affected by higher altitudes. Thanks

 

[87crewdually]

The boost gauge is measuring the pressure of the compressed air in the intake manifold that is produced by the turbo. Altitude = air density

 

[6 Nebraska IDIs]

Basically a boost gauge is telling you what the intake manifold pressure is. On a N/A motor there will be a vacuum in the intake because of the air being sucked in, this is even true for N/A diesels like ours. It may not by much but put your hand over the intake, it'll suck on it. A motor running a turbocharger or supercharger will have a compressed intake charge, meaning the manifold will be under pressure. The boost gauge simply tells you how much psi that compression is.

 

[FordGuy100]

It reads psi above normal sea level atmospheric pressure (14.7psi), so to regerister 1 psi on the gauge the pressure in the intake has to be 15.7psi. 10psi on the gauge would be 24.7psi in the intake.

 

[Willie Two]

Thanks to all, I thought there would be some relationship regarding altitude and now everything is clear. Thanks again.