Turbo_Steve

I now have an HKS SQV VTA Dumpvalve. It sounds the nads when really going for it.
However, when driving normally (i.e. below 3000rpms) it does make rather more noise than I would like.

There is an adjustment screw on the back that I'm a bit scared to mess with after reading the Japanese instructions. If I tighten this screw, will the dumpvalve open only at higher boost?

P1_scooby

I had one of these fitted to my p1, the bolt at the back should definately not be changed/messed/adjusted etc.. can totally screw things up.. get it checked out if you can!!


oops..forgot to add, you can buy additional "fins" which can make the noise louder/quieter etc.. purple one is quiet compared to the chrome/silver one (or is that the other way round!


[Edited by P1_scooby - 2/27/2003 12:40:14 AM]

CataIunya

I am having just the opposite problem not enough noise..... I have messed about with that screw though and didn't seem to do anything...? I think it should be adjusted for idling problems ?

Turbo_Steve

Thanks guys. LOL @ not enough noise! Mine frightens small children and farm animals!!

Guess I should have bought a twin exit dumpvalve. Oh well.

scoootie5

I took my HKS SQV apart last weekend and looked at what the screw actually did.

When its wound all the way in then the piston moves a shorter distance than when its all the way out.
It is just a stop for the piston.

So all it seems to do is adjust how much the piston moves.

Scott

Turbo_Steve

So it's adjusting the amount of boost you actually release, presumably? Hmm...that could be handy.

Bob Rawle

Its actually adjusting the point at which it releases pressure (which is the same I guess)ie 0.3 bar ... 0.5 bar ... etc as you wind it in.

CataIunya

I did the same thing dismantled it today. the bolt adjusts the stopper which adjusts the distance the plunger travels. At first glance as said it just looks like it restricts how far the plunger opens I.e. how much pressure is released. How can this affect at what pressure the plunger actuates.

Bob Rawle

Spring rate is changed.

Bob

Turbo_Steve

So if I adjust it it will stop it popping open to release at stupidly low amounts of boost (I get fluttery noises at 0.1Bar, and a woosh at 0.2Bar, both of which I think are completely uneccesary).

WRX_BLUES

Correct me if I'm wrong, but isn't it a good thing to be releasing any unused boost. I mean isn't that why you bought a a VTA BOV? The standard recirc BOV just does as it says "recirc" any unused boost. I mean if it isn't released to atmosphere where would it go?

Turbo_Steve

It would stay in the inlet pipe and (potentially) stall the turbo. However, Turbo damage only really occurs at higher boost levels. A couple of PSI is not going to shorten it noticibly (esp as the car has done 100,000miles now, and I cannot imagine the turbo will last much beyond 120,000 after a lifetime of abuse).

Subaru's factory dump-valve doesn't dump anywhere near the whole charge. The idea is that it is just a pressure relief...it "blows off excess pressure" rather than "dumps the entire charge" if you see what I mean.

The WRC cars (and I belivee a couple of scoobynetters) don't run a dump valve at all, though I wouldn't go this far.

ChristianR

iTrader: (1)

I don't run a dump-valve anymore

Turbo_Steve

Cool. But then you run a Hybrid turbo too, right?

CataIunya

The plunger goes through the centre of the spring does this still affect the spring rate ? Also the noise comes from my induction kit not from the d/v at all is this right ?

WRX_BLUES

What induction kit you got? If it is what I'm thinking then it's the same as when I changed to a Blitz Sonic Power induction kit. You will hear more induction noise and you will also hear the turbo spooling up more clearly.

Turbo_Steve

The induction kit will add to the whole effect....loads more induction noise (have an HKS induction kit) but the dumpvalve is SO loud it is unreal. On full chat it sounds like something out of Fast n Furious. Unfortunately, it makes little "giveaway" noises at low revs / boost, destroying the cars "sleeper" status.
It may have to go.

CataIunya

I'm sure sommats wrong with mine.....I can't hear any noise from the BOV itself all the noise I presume is coming from the BOV comes from the PiperX induction kit.........It always makes a chatter noise not very loud but audible enough for someone in the car who doen't know about cars to go whats that noise....
But then I have got a catless system with a Blitz nurspec tailpipe and everything sounds quiet compared to that.

CataIunya

My car is obviously a UK MY97 what car are you running it on ? Turbo_steve.....Fancy a swap for a quiet HKS ?

CataIunya

Anybody got a recording of what a SSQV should sound like ?

Turbo_Steve

Mine is on a Legacy (hence the sleeper status) and unfortunately is scuffed becuase the bonnet wouldn't close with it fitted, so I...ahm..."adjusted" some things (bonnet scoop tray and SQV Mounting bracket) with a lump hammer.

Cat, without wishing to sound patronising.....yours is definitely an SQV and not a re-circ? I mean, it is FEARSOMELY loud....like bus airbrakes going of when you are on full boost.

Failing that, drop me a mail and we can meet up at the pub and have a listen. And swap possibly.

Turbo_Steve

Just had a thought: It could be one of your plungers is stuck....the little one makes a kind of fluttery noise that SOUNDS like it is coming from the induction kit...but it isn't.

Like I said....maybe we need to pub it.

CataIunya

Ha Ha......No its definitely not a recirc I have got a bit of broom handle plugging up the manifold pipe I would love to pub it somewhere mines a bit scuffed too.....The only prob is i'm in Macclesfield Cheshire......I bet your miles away...I stripped it the other day and the plunger seemed to work ok and the rubber membrane inside seemed to be intact...One thing I did notice though is that there are small holes in the centre of the plunger that blow when you push it in....Difficult to explain unless you have seen it.

Turbo_Steve

Wow....that is definitely a bit too northern for an M4 boy like me.

If you really want some help, then I wouldn't mind meeting you in Birmingham somewhere, but otherwise I cannot see myself coming up to sheffield unless I'm going to make a weekend of it.

Anything worth doing/seeing with a couple of friends up there?

CataIunya

Ha Ha figured you were darn saaf somewhere....Met a guy from Bradoford the other day and he thought Macclesfield was near Sheffield......Its a good 30/40 miles away......Not mcuh to do up here might be able to sort out a meet in Brum tho got a mate down there...

Turbo_Steve

Brummie-land? Sounds good to me.
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