nonvtec

I was browsing HT and saw a thread mentioning his HKS BOV wasn't working and they talked about a check valve having to be inline with it. I just remembered on my friend's we had one of those too. My BOV (HKS SSQV) has never been really loud, is this the reason? Must be... where do I get one of these "check valves"?

tranceminister

Mine came brand new with a small filter that they tell you to rin inline with the bov. but it works fine without it as well. Never heard of having to install a check valve.

nonvtec

Hmm, cuz on my friend's I remember he had this little thing you could spin, one side was hard and one softer (sound maybe). He sold the car so I can't check it. As long as it works without it I guess I am good. My spool is so loud because of open DP when it blows off it is just a subtle whoosh. So, are you running yours straight to a vac source?

tranceminister

Yup, seems to work fine, but I do get a little bit of compressor surge under light throttle, but I can live with it. the spring was way too tight from factory, even with the adjustment all the way loose.

dsm

well...hks was also built with more than 6psi in mind...i have surge at low throttle (usually 10psi or so) so i'd imagine at a low boost it would totally suck. I noticed it even worse when I went from stock smic to fmic (low throttle)...I guess cause their's more air being compressed. Sounds like sex when you're running 17psi and let off though!

tranceminister

Yeah there is a definate difference when running a lower boost than higher boost. I can full throttle it on the freeway and it screams like an eagle, but cruising around I get a slight "whoosh" and a little flutter. No big deal. I havn't tried it with anything less that 10 psi, so I don't know exactly what to expect.

Turbo-Dan

my bov made compressor surge all the time (i was only running 12psi max) and i didn't like it so i took it apart and removed the spring from inside the unit, now i dont have any flutter, even at .5psi. i just get a nice whoosh, and anything above 6psi i get that scream of a noise that gets louder with more boost.
no compressor surge here anymore.
the only slight drawback of doing this is it is open at idle, which doesn't bother me but it might bother others.

if you are bored one day and want to get rid of some low boost compressor surge give that a try, it has worked flawlessly for me for years now.

a check valve in the vacuum line of the ssqv is useless.

Reddy

Am I reading this right that you don't have a spring in your BOV

Turbo-Dan

this is correct
i ran 13.8 @ 99mph with no spring in my bov.

its because of the design of the ssqv, the boost keeps the bov closed, which eliminates the need for a spring.
as long as you are boosting with the ssqv there is no way it can open.
the ssqv is a pull type valve

djfob

hmm intersting.....never knew this about the ssq