I was wondering how the vacuum line from the N75 to the WG affects how the WG functions. Would disconnecting the line cause overboosting or cut off boost? Thanks.

 

The N75 regulates the vac/boost that actuates the waste gate. It overrides the 5psi waste gate spring to keep the waste gate closed and you in the boost.

If you disconnect the vac line to the wastegate you will only be able to boost to 5psi before the waste gate opens on its own, a form of fail-safe.

 

I was just reading up on MBC's right now and it sounds like it's the opposite of what you said. I read that less boost pressure to the WG causes boost to rise, which is what you are adjusting when you turn the **** on a MBC. So disconnecting the vac line completely, sounds like it would make the turbo run at maximum I'm guessing. I also read that running a vac line straight from a positive boost source to the WG would cause minimum boost.

 

Maybe my understanding is incorrect. However I'm fairly certain that the internal spring is rated for 5psi.

 

I agree that I've heard a few people say that our WG's have a 5psi spring. So I guess that's the least amount of boost that can be made.