Can you tell me what the second vacuum port is used for here? Im used to only using one port, and cannot understand why you would want a second.

just a guess

looks like there is a port on each side of a diaphram, and since one is on the pressure side, to open the wastegate - I'd expect the other side is a vacuum side, to pull closed the wastegate - since I see no return spring

[This message has been edited by Pyrthian (edited 03-28-2008).]

It is for a boost controller..
it splits the pressure between the sides of the diaphragm to raise the boost pressure..
Chuck

quote Originally posted by MotorTV: It is for a boost controller.. it splits the pressure between the sides of the diaphragm to raise the boost pressure.. Chuck

Ed Zachery

quote Originally posted by MotorTV: It is for a boost controller.. it splits the pressure between the sides of the diaphragm to raise the boost pressure.. Chuck

I see, but that design seems a little overkill, dont you think?

Typically you would just put the boost controller in series with the top port, decreasing its signal and increasing the boost.

So, its safe to imagine that I can just leave that open. Still dont understand why you would need two ports

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Here's my take: Being as it is a rubber diaphragm, it isn't good to just leave it open to the elements. I'd guess that if nothing else, it would be good to attach a line to it and attach a small filter, so that as little dirt as possible is pulled into it. It may last longer that way...

-Darryl