The function of the pressure relief valve is to control the pressure in the intake pipe below the limit value.
This limit value should not only take into account the needs of the engine,
but also consider the pressure range that the intake components can withstand.
The external exhaust bypass valve (External Wastegate, commonly known as Wastegate)
exhausts the pressure directly into the air, which can produce obvious pressure relief sound.
The function is roughly the same as the "Actuator", but the structure and installation location are different.
Structurally, "Wastegate" eliminates the connecting rod and the exhaust valve in the turbine.
In terms of location, "Wastegate" is installed independently between the turbine and the head section of the exhaust pipe, and does not need to be attached to the turbocharger body like the "Actuator".
Once the turbocharger value reaches the set upper limit, the "Wastegate" discharges
(which can be directly discharged to the atmosphere or returned to the exhaust pipe) excess exhaust gas,
reducing the exhaust gas flow that "blows" the turbine wheel, so that the turbine maintains a stable boost value.
"Wastegate" has a larger boost capacity than "Actuator" (large springs can be used) and responsiveness,
so it is more suitable for use in high-horsepower or high-charge turbo engines
Note
A very important part of a turbocharged engine is the intake pressure relief valve, Blow Off Valve
It is located after the compression side of the turbo and before the throttle.
Theoretically, it can be installed anywhere in this section of the pipeline.
The function is to open the valve through the vacuum force when the throttle is closed,
and release the compressed air in this section of the pipeline so that the next pressurized gas can flow in smoothly.
The intake pressure relief valve relies on the internal spring and the pressure (vacuum) of the intake manifold to determine the opening and closing of the throttle valve.
