i recently bought a 14b turbo and the wastegate exhaust hole is covered with a piece of metal(no air can escape). can anyone explain why it is covered and why would you want this? should i just unbolt the metal piece when i put it on??

 

Some one was probably using it with an external wastegate.

 

Correct - to convert to an external wastegate, you unbolt and ditch the internal wg, and weld the flapper door shut (either with the stock puck or a piece of metal).

It works well, although the flow gets disturbed as it passes by the (now closed) wg hole on the inside of the turbine. But you don't have much choice about that, unless you want to machine a short tapered piece of metal that inserts into that hole and seals off the entire wg hole like it never existed. I don't know anyone that would spend that much time doing that though...

- Slater