What is the difference between the internal and external WasteGate ?

[skylineowner]

hey

can someone please explain the difference between them .. am really confused !

Thanks

[MarkMcQ]

Ok, obviously we have to get the sarcastic answer out the way first:
One is internal, the other is external.

Internal wastegates are built into a turbo and are activated using pressure which pushes on a diaphragm, which in turn moves a wastegate arm, opening a valve which bleeds off excess exhuast gasses to stop the turbo going over a preset boost level.

An external one does a similar job but the gasses are diverted through the wastegate unit itself rather than inside the turbo.

Here's a turbo with an internal one:



And this is an external wastegate. In this case an HKS model.:


And here's how an external would be set up to work:

[skylineowner]

Thanks Alot !

[SmigzyGTR]

i think this should go in new users FAQ.

Edit: done