Hey I just got that same BOV for testing.
Being open is more like a bypass valve, allowing the turbo to free spin while cruising. I bet the turbo is spinning a little faster as well with no load.
Normally bov are closed while driving and only lift when vacuum is on one side of the piston and boost is on the other side.
I think you will be fine. The blow off you got has a much small hole then a Tial or others do.

 

I got a ? I've never seen Synapse BOV in person. Do the have a filter in them? My thought was they would let in unfiltered air.

 

Hmm...I was thinking that if the BOV wasn't open it would be forcing air into the engine, allowing me to back off the throttle quite a bit. I have noticed that when I'm on the verge of getting into positive manifold pressure that if I very slightly tip the throttle just enough to make the BOV shut, the boost will instantly shoot up to 4 or 5 psi. All of the air that is escaping before the BOV shuts just seems like wasted energy to me, although I didn't think about the free-wheeling nature of the turbo when that happens, and that shutting the BOV would effectively create more restriction in the exhaust. But then I start wondering about how the wastegate would react to that...ahhhh I'm confusing myself!!!

I don't think there is ever a time when air comes IN through the BOV, but I did put a small filter on the BOV awhile back, just in case.

 

The Synapse one is different, I think it was designed to stay open until you get into boost.

That chatter is still compressor surge. It has to do with the volume of air, not necessarily being in boost. The reason I bought the Synapse was to get rid of all of the part throttle surge, which it does very well. The actual performance of the Synapse unit is fantastic...I'm just trying to figure out if the tradeoff is greater inefficiency because of the nature of the BOV staying open rather than closed.

I do get into boost a lot, or right on the verge to where I can hear a lot of air escaping through the BOV. I don't really want to mess with the TC right now...I'd like to figure out this part before I go and try to put a bandaid on it.

Yeah I really like the performance of this unit, I just want to figure out if there's a tradeoff.

 

My bov does the same thing as yours colton. Even at as much as 10in vac... Doesn't feel like compressor surge though... Weird.

 

I forgot to tell yall, i dont have to be in boost to get Compressor Surge..
Kinda strange, but when we went riding that night in coltons truck, mine does the same except i got the butt mount.. BOV is in the front, but cant hear it yet cause its prolly got a 25# spring..

 

I think you will be fine, if you can get use to the hole boosting differently thing. I have not had time to install mine yet.

 

so if you have a 25 pound spring are you ordering a lighter spring or are you just cutting the 25# one down.

 

a standard BOV's spring only needs enough pressure to keep the valve closed at engine vaccum while deaccelarting. Anything more is just a waste and will keep the unit closed to long, in my opinion.

The instructions for the synapse does mention an air filter on the discharge is not plumbing back in, but I'm not planning on running one.

 

we just installed one of the synapse blowoff valves on my friends gti. your suppose to recirculate it, if u dont put a filter on the end, or get the "anti-stall" insert. its been workin great for him, no compressor surge and it doesnt leak. does its job