Would make a racket when open.

 

I guess that's the point. I put small mufflers on my external wastegate outlets to quiet them down.
That exhaust is not for me. Lol

 

The prices aren't bad for quality, not for me but see what your going for.

 

Well, think about it. Wastegates are designed to vent and bypass exhaust when a specific boost is reached right? Simply plumb one into your exhaust such that it opens and vents when you hit whatever boost you want except that instead of regulating boost it will be venting back pressure from your quiet exhaust. It's made to take waaay more heat than any of these swing valve and solenoid combinations! Take the output from the wastegate and vent it however you want, same as you would if it were regulating boost. Make sense?

Thinking about it, you could probably even make the boost reference the exhaust system such that when back pressure builds it could be used to release vs boost, might work for NA too but probably cycle funny and chuff.

 

these swing valves are actually internal wastegates and are def made to take the heat. essentially what you are saying would probably work but would sound pretty ugly - in my opinion.

 

even if you used 1 bar w/g you still need a butterfly of some sort. by the time you piece this all together your spending more than its worth. go with aftermarket w/g and they are still 2.25" and now you have a restriction thats bad for turbos. this isn't cheap but looks like a complete setup if this is what your looking for

 

Ah internal W/G ought to work but most of the valves I've seen are awful. Not sure the sound would much different, all you're doing is relieving pressure in the exhaust and you'll still have flow out the normal path. Honestly my exhaust is probably free-flowing enough not to sweat ever needing something like this but I could see needing it on something corked up. I'm doing pressure monitoring with a stand-alone soon, might be interesting to measure it after the turbo too and shouldn't be too hard to do once it's already hooked up.