Blow Off Valves: Opinions, Experience

[andrave]

Everyone has a lot of questions about the various brands of blow offs, and if you are choosing to go with one that isn't that popular, searching won't yield many results. Trust me, I'm going with a sheepdog and I haven't been able to find much. themadscientist, from 240sx.org, is in Japan right now and he sent me this in an email where I asked him about the various kinds of bov's. This was his response, and I thought it might be helpful.

As far as blow off valves go here are my experiences with various types in order of favorites;

(Trust Type R) Big and beefy "the" blowoff for big huffers, won't open up at all on a stock turbo under 14lbs, consider it pipe! It can be hooked up to a hose to route the air back into the intake pipe if you want to.

(HKS Type R) pretty much the same deal as the Trust, bulletproof.

(Trust Type S) solid construction with good response but still capable of handling larger turbos. It can be plumbed for a return hose which is sometimes a needed option A great street valve money well spent.

(Blitz Supersound) Comparable constrution and performance to the
Trust-S but ungodly loud. At 14lbs in my wife's car it can be heard 100 meters away. (This is the older type, I have no personal experience with the newer one, it looks a little weak to me though)

(HKS sequential) The old one was crap, I blew one of the plastic peices of crap to bits once. The new one is aluminum so it should be o.k. It has a tweetybird sound that I can't stand though and it can't be routed back into the intake if you need it.

The sheepdog I have is the early model with a round outlet, no horn so it can be routed back if needed. It was on a CA18 with a wastegated T300S. The headgasket on that motor went south but the blowoff survived, testament to it's strength. I would guess it tweets like a sequential.

[Jeff240sx]

Originally posted by andrave
(HKS sequential) The old one was crap, I blew one of the plastic peices of crap to bits once. The new one is aluminum so it should be o.k. It has a tweetybird sound that I can't stand though and it can't be routed back into the intake if you need it.


The new one, the Super Sequential, can be routed back into the intake piping. You need to buy a little piece from HKS for it though. Also, there are different fins you can buy to change the sound of it. Finally, if you're pushing enough boost, you won't hear the "tweetybird" sound, because the large valve will open up very fast.
-Jeff

[Muzzy]

i thought the blitz BOV made that "woosh" sound...

[andrave]

fresh alloy doesn't even have all the information this thread does.
trust me, I searched.

[nrcooled]

(Blitz Supersound) Comparable constrution and performance to the Trust-S but ungodly loud. At 14lbs in my wife's car it can be heard 100 meters away. (This is the older type, I have no personal experience with the newer one, it looks a little weak to me though)

DO NOT BUY THIS BOV!!!!!

It is made for cars w/ MAP sensors. For 240 owners w/ MAF sensors you will spend most of your time restarting your car because you will be stalling all the time. It is loud but not that loud.

The TurboXS is the loudest that I have heard. Just spend you money on the HKS SSQV and you will be happy. Function over form

[Foxcolt]

(HKS sequential) The old one was crap, I blew one of the plastic peices of crap to bits once. The new one is aluminum so it should be o.k. It has a tweetybird sound that I can't stand though and it can't be routed back into the intake if you need it.


FYI: The first HKS sequential Bov is still today one of the best on the market. Affordable and built to last these are one of the best BOV's bar none.

PS: None of the HKS series BOV have any plastic in them. They are all metal. Except for the diaphram part, which I suspect is what this person is talking about.

Your faq should be deleted as it contains a lot of false information and nothing concrete whatsoever. I'm afraid people will look at that and base their opinions on yours therefore leading themselves to make stupid decisions. I understand you wanted to help but spreading someone's opinion as fact isn't the way to do so.

[andrave]

its not stupid, and its not my opinions. Its someone who lives in japan and has used a lot of bov's.
If your experience are different than
DUH!
post them here.
Its by no means designed to be the encyclopedia on bov's. that was HIS experience. if YOUR experience is different, than by all means post it. anyone who reads what I type will read what you type too.
notice I never said this is fact. this is in someone's experience. it clearly states that.

[BlitzSilvia]

I keep hearing bad things about Blitz's new bov. Anyone have any opinions on it? I've been planning on going with mostly blitz and JUN parts for my 91, but if the blitz BOV is asking for trouble, I might go for the HKS Type R. Thanks.

[andrave]

I have heard a lot of bad stuff about the blitz valves leaking at idle and making the sr/ca motors stall. and this is on 3 forums, between maybe 5 or 6 users, all having the same type of problems.

[uiuc240]

dammit

the blitz is just fine if you tighten it enough at idle. but then it doesn't blow off as well. just recirc it.

Eric

[lbcklik1486]

I'm looking for a woosh, but a higher pitch woosh, not a tweety bird noise though. I've heard the hks ssq is pretty loud, but can be made lower w/ more boost and can get different diagphrams to change the noise, am i making any sense?:confused:

[s14vaxlr8]

the hks is extremly loud and i have yet to adject the tension, @ low boost it does sound like a dove or something, but high boost .5-.9 screams

[240Stilo]

For something that works and is reliable how does the Bosch BOV measure up?

[cdigity]

is this a beauty contest????
who cares about the sound!
as long as that bitch blows off and releases pressure
without stalling your car,than its good!
if you guys want sound go buy that fake ass siren
blow-off kit that taka-kaira sells for like $200+
oh yeah, i have an HKS ssbov , works great!
have'nt rated the sound yet!
mine sounds like a duck in heat:p

[andrave]

the one from the eclipse? the stock bypass valve? it works as a bypass valve but not well as a bov. there are sites around that show you how to modify it to hold different levels of boost and how to modify it to blow off to atmosphere.