Working on a turbo project, finishing mocking things up. Just did the last of welding, which was putting in my external wastegate. I got it at the best angle I could - Less than 90 degrees to exhaust flow

Just wanted to test the welds and wastegate itself for exhaust leaks so I fired her up with an open dump and no vacuum lines hooked up to the gate.

No exhaust leaks at all, but..

When I put my hand up to the open dump I can feel and hear it sucking outside air INTO the wastegate. It must be a vacuum effect from the flow of exhaust.

Im no expert but I've been thinking about this and I can't seem to wrap my head around what's going on, if it's because of my angle, or if I need to take apart the wastegate and look for bad parts

If it helps this is a 2 bolt flange wastegate with some type of valve seat ring that you put in between the two flanges, and as you tighten the flanges the gap from the 'valve seat ring' decreases. It must be pushing the valve up and seating it?

 

Wouldn't worry about, hook up some lines and make sure it functions.

 

well, it should be closed and not leaking.
But if its a small leak and you have a seperate dump it should be fine.
If you are dumping it back into the rest of the exhaust system it could show a bit lean at idle.
But if you give it what it wants it probably wont be an issue.

 

Do you have the fire ring in place?

 

Yes, that's what I described as the valve seat. Didn't know it's called fire ring. Looks like it can go in either way but I faced the lip side to the wastegate and flat side to the exhaust flange

As I tightened it, it closed the gap between the two flanges

Without it i can tell there would be a major exhaust leak

 

Maybe try cranking on the pre-tension a little to c if that helps?