A little history first,
So a friend of mine buys a $700 ebay turbo kit. I was against it, but now we have it, so we need to make it work.
On the wastegate that came with it, there it a line that goes to the top, and another that goes to the bottom. I know, or at least I think, the line on top is the boost sensing line. But, what is the bottom line for? I am used to internal wastegates, and seeing just one line. I don't really see the need for another line, but figured you guys would know.

Thanks.

Assuming it's a similar design to say a tial, your boost source goes to the side (bottom) port and the top port remains open

See, this is why I love this place. I was wrong... I guess that makes sence, because of the way the actuator is situated for an external wastegate.
It is some JDMsport crap... but I am sure it functions much the same.


Thanks!

I have an ebay "no name" brand Tial copy, and it's worked great so far. No complaints here. And yes, to confirm the above you hook a line up to the side port and leave the top open.

The top would be for a manual boost controller if i'm not mistaken.

The bottom port is for boost. The top port can be unused, or ran with a check valve for vacuum only as an assist.

wtf is wrong with you all. lol

bottom port goes to your turbo.
top port is left open, or if you have a boost controller, it is used.





if you take away the boost controller (regulator in the last pic), notice how the bottom line goes to the turbo compressor housing, and the top of the wastegate is left alone.

Mikey, your pic doesn't really make any sense. How is the boost controller doing anything if it is attached to the top of the WG? It doesn't look like that would make any difference on your boost pressure? What am I missing?

I agree Mikey......WTF is wrong with you guys.....you just get off the boat?

Top port is used with a Electronic boost controller. The boost controller will use boost pressure to force the wastegate shut though the top port. Read up on boost controller solinoid operation....I dont feel like writing a book.

Originally posted by StarTurboEclipse
Mikey, your pic doesn't really make any sense. How is the boost controller doing anything if it is attached to the top of the WG? It doesn't look like that would make any difference on your boost pressure? What am I missing?

It creates a neutral pressure bias in the wastegate, equal pressure above and below the diaphragm. The spring in the wastegate only works when the pressure in that chamber is lower than the other side of the diaphragm.

This all makes sense. Thanks for the help!