If a turbo has an external wastegate, how does it regulate boost? I know how the internal WG works but I still dont quite comprehend how the EXT works.

thanks

Blaze

 

External wastegates vent pressure before it reaches the turbo housing (ie from the manifold). The vented exhaust gas from the manifold is then routed via downpipe to the exhaust before the catalytic converter, unless you run open downpipe.

That's why you want to vent from the central collector on an external w/g turbo mani - otherwise you're only venting 1 cyl worth of pressure, which may not be enough to control pressure buildup in the manifold, leading to boost creep.

 

Is there any advantage to running an open dp? over a closed one? If so, what is the advantage.

Thx

 

Better flow, imagine trying to blow through a straw..... now get a 1in pipe, which is easier to blow through?

thanks raene

Blaze