Wanna hear my 1G DSM BOV?
 

Here's a link to the install... definitely going back to the Bosch next time I'm under the hood:
https://www.miataturbo.net/forum/showthread.php?t=23454

1G DSM w/ 1" ghetto-fab inlet and stock outlet. Flutters like a big big big DOG! I hope you get the idea... it's a lot more obviously loud playing it uncompressed... and it's ANNOYINGLY LOUD AND STUPID from the drivers seat.

ew.

Dang. I had a 1G on my Greddy setup and it worked like a champ without an ounce of flutter. I was using it VTA with a "crushed" can on the BOV.

Weird....

Most of the ones I've heard do the "psssht"...

seems odd... that's usually caused by too much spring in the BOV. Maybe your vacuum source isn't large enough for it. What size vac line are you using?

That was happening to me. I stuck my finger in the opening and just pushed around and it hasnt done it since then. I also got a foam pool noodle toy and cut a small piece and put it around the VTA opening and its a lot quieter.

I wonder if it's sticking... can you lube it?

yeah, some powdered graphite works wonders in my bov. Just dust a little in every few months.

If there's one thing I'm good at... it's applying lube.

Thanks for the tips. Next time I'm in there I'll swap out the Bosch and perform the recommended actions on the DSM... then time after that re-install and report back.

I think part of the problem might be the restriction I've created in the exhaust port. The stock exhaust port is about 1-5/8"... and I'm running a 1" pipe on the end. I'd assume Mitsubishi made the thing a certain size for a reason and my application is causing a backup in the exhaust and causing the flutter.

I ran mine with a 1" pipe and it worked perfectly fine, didn't sound anything like yours.. Wierd

yeah sam, yours sounds more like comp surge

id take that off asap till you get it to stop. it might be stuck, or the spring is just too strong

that doesn't sound like compressor surge, it's definately bov flutter.

Is it crushed? Sometimes people crush them improperly and can cause problems.

Uncrushed.
It can't be surge because it will flutter even if I simply stop accelerating in vaccum. I don't even have to get it into boost to flutter. In fact, it will flutter with just a light stab at the throttle in neutral.

I say shoot some WD40 in there, if the valve is designed to withstand blowby oil i'm sure it can handle WD40. Or go with powdered graphite like he suggested. Worth a try anyway.