Ok, this is probably going to sound really stupid....but could someone explain what a dump valve is used for?...what are the advantages?...and if it is advantageous, would it improve the old P1?????....if so where can I get one?... who could fit it?...and what would it cost?...other than that I guess I'm sort of up to speed...

Ta

Tom (Rum*)

It makes lots of noise and actually wakes up the dozy barsteward sitting in the outside lane and not checking his mirrors.
HKS Sequential Blow Off Valve. Love it!
Releases pressure in turbo so it spools up quicker. Allegedly.

The dump valve or blowoff valve, BOV keeps the turbo spinning when you step off the loud pedal, reducing lag.
If it didn't the turbo would stall, and have to spin up again when U reaplly loud pedal.

And there's one already on your scoob...the later models are said to be efficient anough, and if it's the sound your after get an induction kit.

/Jerry - Sweden

I had one fitted (Forge) and it hasnt got that wooshing sound as I did not want that.

Yes it does make a difference I think as I had the turbo done at the same time but it holds on to revs better when changing gears.

Saj
STI V

I know it's Cosworth biased, but this page has some good dump valve info ...

Interesting you got one from Forge Saj,
when i emailed them they said they couldnt supply me one for the sti5!!

problems mounting it apparently......

Rum,

Replaced the re-circ dump valve on my UK94 for a piston type dump valve which made the typical "ppptttssshhh" (scared pedestrians at 500 yds!). It did improve through gear responsiveness ~ with lots less lag. Rough cost £80

Since then changed it for an APEXi BOV, which as far as I can tell is exactly the same apart from looking chome and shiny.....except that I got fleeced for 250 quid.

I can't tell any difference, but it was recommended that I have it fit as it dumped the air faster and would result in even less lag.

I think I've been had http://bbs.scoobynet.co.uk/frown.gif

Mark

Got mine from BR Developments fitted fine about 10 mins.

Saj

Ok....so we've got the "...ppptttssshhh..." bit...now the questions is....would it benefit the P1??? apart from scaring the $h1t out of pedestrians @ 500 metres??? http://bbs.scoobynet.co.uk/biggrin.gif Not that I see a problem with that ! http://bbs.scoobynet.co.uk/biggrin.gif...do any of you think it would improve performance??

a not so puzzled Rum

Cheers Lads

Performance......yeah if shifting quickly I think it makes the pickup better in the next gear. I haven't performed anything scientific.

Anyway, its a safety device...people can hear you coming http://bbs.scoobynet.co.uk/biggrin.gif
My excuse to fit one, was so that you could hear it all the way up Harewood http://bbs.scoobynet.co.uk/biggrin.gif http://bbs.scoobynet.co.uk/biggrin.gif http://bbs.scoobynet.co.uk/biggrin.gif

Can't comment on P1 specifics.

Cheers

Mark

Mark,

How did you get on the other weekend??

hanks for the comments - I could do with chatting a wee bit further on it sometime - so might have to come down your way for a drive sometime *S*

I always like the idea of audibly warning folk that I am coming up fast behind them.....

....just re read that - can't believe I've actually typed that http://bbs.scoobynet.co.uk/biggrin.gif http://bbs.scoobynet.co.uk/biggrin.gif !!!!......You know what I mean anyway.

All the best

Tom

The last event at Harewood (10th Sept) was wet, which was a shame as its ever so slimey when the tracks wet and times were slow.

Also a shame, cos its possibly the last outing of the Scooby at Harewood...Read POSSIBLY...

Next season we're looking at playing in a tweaked ex LAD Motorsport 205 GiT with about 170 at the flywheel ~ It just won't be the same though.

I'll miss competing in the Subaru, but breakages aren't cheap, and this season has been plagued by them.

But now its fitted with an Apexi fuel controller, and a boost controller which has been professionally set up rather than me tweeking a bleed valve which could have easily ended in disaster again.

Cheers,

Speak to you soon.

Mark.

PTHolt

Branko of BRDEv has a Forge MS one fitted to his StiV no probs.

I do too to my inferior UK heap

I guess they sound different when running link also Saj?

Sunil

I have a dump valve lying around from a friends RS,I went to my nearest subaru specialist to see if they could fit it but they said it wouldnt work?
They then tried to sell me a Blitz blow off valve for £280!!
I am now confused,can I fit it or not?,were they having me on trying to get a sale?
Help please.

A friends RS?....what - a ford?????????, how on earth could that fit on your scooby??????????????????????????????????

Please clarify

Sunil

[This message has been edited by sunilp (edited 29 September 2000).]

Rum,

I have just recently removed my Bailey Evo dump valve and put back the standard '98 one, because the car is going for a service, and I wanted to put it back to standard.

I have, however, noticed the car seems a lot smoother since I have removed the valve, so am considering whether or not to re-fit it after the service or not.

I now have my Bailey dump valve lying around, so if you want to borrow it and seeing as you only live 'round the corner http://bbs.scoobynet.co.uk/wink.gif' you are welcome to give it a try and see what you think. Fitting only takes about 5 minutes.

Col,
The reason the dump valve from your Cossie(?) won't work is that beacause the Impreza has the air flow meter before the turbo it requires a valve that is closed on idle (like the Bailey Evo which I beleive will only open if boost pressure is over 4psi). Standard diaphragm type dump valves are open at idle - which causes idleing problems. This is due to the air flow meter reading the amount of air entering the engine and adjusting the idleing accordingly, but this reading is incorrect as some of the air is escaping through the open dump valve. - RS Turbos have the same problems too.

Sunilp,
The Bailey EVO dump valve I received from Power Engineering is identical in size and shape to that fitted to my mates Cosworth. I think the EVO ones just have a stronger spring or something. I guess if you had a Link (or other) mapped car (like your own) you could (if you wanted) use a Cosworth dump valve.

Cheers

SimonM

http://www.evosix.f9.co.uk/terzo.jpg


[This message has been edited by SimonM (edited 30 September 2000).]

Simon, i never knew that!. The only thing is as soon as i fit a Cossie part to my Scooby, its bound to break down isnt it? http://bbs.scoobynet.co.uk/biggrin.gif http://bbs.scoobynet.co.uk/biggrin.gif http://bbs.scoobynet.co.uk/biggrin.gif http://bbs.scoobynet.co.uk/biggrin.gif http://bbs.scoobynet.co.uk/biggrin.gif