I just had an idea that I would like to put out there. Could I put the springs in a vice and, compress them a little and heat them with a torch to reduce the tension a bit?

It's a decent whoosh right now, but I can hear some faint compressor surge still (definitely not BOV fluttering). That said, there is still a bit of adjustment to be made, lubricating the BOV piston, and switching from a 3/4" bung to a 1" bung (stupid old 323GTX valve was 3/4" opening), hopefully getting a better blow-off.

Are you getting surge or is the BOV cycling open/closed?
Most BOVs in miatas don't get enough vac signal to open properly or stay open at the end of the blow event. IM ports are too small.

ryrye- compressing the spring (permanently) would be the same as the adjustment screw, so if you're out of adjustment, I say yes. I'd avoid the torch on a little spring. I'm still amazed that the weakest spring is producing that much tension. Did you guys get three springs? (I did)

I'm running a 1" bung for the bov.

oh it is most definitely compressor surge as i relocated my bov to just after the IC so its right in the mouth of the car, but I hear this sound coming from right in front of me (out of the intake piping. I am just sort of surpised that my temporary ABS piping hasnt blown off lol. Even with the slightest of spooling, I get this slight snickering sound and when I spool it up for real, it gobbles like a turkey and people look at me funny. If your wondering what vac port I am using, it is the one that the Charcoal canister used while it was still in the car

I get that exact same sound. I'm using the vacuum port that the VICS solenoid normally uses on the 2000 manifold. The hole for the vacuum line on the BOV itself is really damn small, though.

-Mike

It takes very little to compress/ decompress that little chamber in the bov, I would be surprised if it was caused by not enough vacuum.

VICS? Don't use the VICS vacuum source to the VICS solinoid. It comes from a reservoir chamber in the intake. Use a direct vacuum source like the line before the check valve for the chamber.

I drilled and tapped my IM for my Tial BOV to eliminate any flutter. I used 1/8" NPT fittings and it cured it all. My WG signal comes from the compressor though through the GM solenoid.

Hrm. I suppose maybe I'm not using the VICS one. I don't actually have VICS working right now, for one thing. The port I'm using is on the top of the manifold, facing the engine, approximately above the first intake runner.

-Mike

fwiw - I'm using a vacuum port that's immediately after the throttle body on the underside of the manifold.

I just gave up on this damn piston style POS. I tried everything to make the thing blow off and it just would not. Basically the design is shit and its never going to work right. It sucks to be limited again to 11-12psi again ( not blowing off gave me a nice steady 14-15psi to redline) but at least it isnt gobbling anymore :(

I can hold 15 psi using a cheap plastic bosch BOV from a VW.

well i have a bosch that came with my begi kit and it will not let me go past 12ish psi other than a quick spike to 15 when i mash it

I wonder if it's just the lack of qc on the piece or if yours was different mechanically - I know ben said his was different.

When I installed this bov my boost peak went to over 17psi from a peak of 14psi on the bosch. With the bosch I couldn't get anything to higher to hold with the MBC. It would just shoot up and immediately fall back down accompanied by a loud whistling sound. This was the more expensive "metal" bosch - but I'm sure there's some tolerance in quality and tension among those units too.

i might be getting the part that you got, or I may just suck it up and buy a forge or something like that

Are you sure you guys are putting those valves in right? Post pictures.

I just put the red non recirc BOV in from this thread. Got the gobbling at first but then loosened the spring tension on the spring that was installed (got two) and now it's blow off fine. That's at 11 psi. Shouldn't be a problem to go hight as I should be able to tighten it a bit if need be. I'll probably pump 15 psi through the system and see if it leaks.

Frank

Sorry to bring this back from the dead, but I just got around to installing my turbo setup with VTA BOV people here have been having problems with, and sure enough, I too am having compressor surge.

Is it ok for the BOV to leak at idle? Also, did anyone figure out the best way to fix this, like try new o-rings, different springs, etc? Or did the people with the bad ones just buy the same one M2Cupcar had that can be used for recirculation? Thanks!

You guys need to stop going cheap on valves. It hurts me to see it.