Bakerboy

Hi guys,

I want to change the dump valve on my standard uk 03 sti, as I was dissapointed that the standard car has a 'silent' dump valve, and I have a few questions to ask if you would be so kind to answer;

1. How much would a replacement dump valve cost roughly including labour?

2. Would it increase the bhp at all?

3. Would I need to remap after I get one fitted?

4. Why don't subaru fit one that you can hear? It suits the car much better and surely a piston type dump valve is better for the engine?

Thanks guys,

Bakerboy out.

Elmer Fudpucker

GeoffMM

i fitted a scoobyclinic adjustable dump valve as after a while you will get annoyed and want to turn it down. It was £175. Dont get a blitz ssqv cause they are really loud and you always see them on ebay as people get bored with them. I only have my dump valve set just on so that you can hear the psssss

RB5_245

1. If you can manage to put fuel in the car you can manage to change a dump valve. It's easyer than changing a wheel! Dunno how much they cost these days though

2. No, not in the slightest. There is no performance benefit but it can make the car a little lumpy on gear changes as it overfuels.

3. No.

4. First point would probably be preferance, I certainly wouldn't like a new car to sound like that and i think the majority would agree.

secondly, the ecu bases fueling on many things, including the amount of air passed through the airbox. If you fire this air out to the atmosphere after it has been measured then the fueling will be wrong while the valve is open. This would give emissions problems and will damage the cat over time.

Dave

dunx

iTrader: (3)

Fit it yourself, two bolts, one pipe, and a bung with a clip.... Easy if engine is cold ! Mine wasn't doh!

1. Cost £150 ish, but many are selling up to go back to a re-circ (std). So be cheap on fleabay....

2. Not a single pony, but might make you drive it harder ???

3. Not needed, unless a mapper can state otherwise ?

4. Farmers would scare their sheep ! Many of us older folk don't like them noisy, ( good taste ), some of us allow the inner chav some freedom.... buy something to make more power with the money instead.

It's your choice really.
I think it's better for pedestrians to hear me coming....

nik52wrx

Point 4:
I guess Subaru dont fit them as standard because i would imagine 95% of owners dont want them. Not everyone wants to drive down their local high street going pssssssh at every gear change.
Nik.

Bakerboy

I had a look on ebay, can't see any dump valves for sale for an 03 sti - only a standard subaru one...

Any idea where else I can get one guys?

RB5_245

RCMS, Demon tweeks, flat4online, jw-racing, extreme scoobies... and a hundred others, anywhere that sells anything shiny and car related really.

Bakerboy

Can replacing the standard dump valve on an 03 sti dmage the engine at all? I'm hearing mixed opions from friends etc..

davedipster

Don't do it, you will waste your money and your car will drive like a pig.
simple.

scooby_matt

Post 4

reano

iTrader: (2)

This has to be a wind up .....

Bakerboy

Why is nearly everyone so against and rude about something I want to do to my car? Each to their own, I wanted advice not opinions.

I've orderd an adjustable one: Greddy Type RS BOV Subaru Impreza 00-05 Flat4online.co.uk Subaru Impreza Mitsubishi Evolution EVO Walbro Fuel Pumps Injectors Intercoolers

which from reading from one of the more positive and on subject posts, it looked to be the best option for me.
Without any more digs, my engine shouldn't have a problem with me being able to adjust the dump valve right?

scottstotty

Here you go mate. Get yourself a HKS SQV. Its what my mate has got and it sounds awesome. Only took 15 minutes for him to swap over.

He bought it from this seller on Ebay. He is cheaper than most places as everybody wants around £280.

eBay.co.uk: Subaru Impreza V8 HKS (SQV) Blow Off Dump Valve 2002+ (item 230055915220 end time 02-Dec-06 21:04:22 GMT)

Scott

Graz

Wrong

Bit more too it than that. It will overfuel and as well as the above symptoms can cause bore wash, thus over time diluting your engine oil with petrol and may ultimately cause catastrophic engine failure.

Stick with the standard re-circ dump valve. Your car will drive better for it and it won't sound like all those clapped out chav mobiles you see cruising round town grrrr-pssssst-grrrr-psssst etc. So ghey.

Bakerboy

Thanks scott, I just orderd an adjustable one for £225 as mentioned in the above post which seems to be the best option for me.

Greddy Type RS BOV Subaru Impreza 00-05 Flat4online.co.uk Subaru Impreza Mitsubishi Evolution EVO Walbro Fuel Pumps Injectors Intercoolers

It looks to be more complicated than the standard one's to fit - does anyone know how to fit these one's or know where I could find out?
I'm very mechanicly untrained, and would leave it to the professionals unless it's still really easy to fit..

Bakerboy

catastrophic engine failure? are you sure that you arn't letting the chav's cloud your judgement on a simple mod? Everyone is titled to their own opinion ok, just cos I want a dump valve DOES NOT MAKE ME A CHAV.

Surely major manafactures like HKS and GREDDY couldnt sell them if they caused 'catastrophic engine failure'?

Bakerboy

The advert reads: 'for the 2000-2006 Import & UK Subaru Impreza STi. Allows for recirculation into the intake or venting into the atmosphere with the unique discharge fitting. Greddy blow off valves are easily adjustable to prevent both premature boost leakage and compressor surge.'

So I shouldn't have to worry about engine failure would I?

scooby_matt

Sounds like you want someone to tell you want you want to hear.
You've been given advice and you're still deciding to ignore it, so why ask?

RB5_245

Actually you're wrong. Please provide evidence of one subaru engine suffering an engine failure through the fitting of a dump valve.

There are thousands, upon thousands out there. This is just a scoobynet myth based on a worst case scenario which doesn't happen. Yes it over fuels, no it won't cause borewash.

It will kill your cat over time, otherwise it is perfectly safe to fit a dump valve.

I don't like them personally but as said, each to there own.

Dave

RB5_245

Simple to fit. Remove the old one. 2x10mm bolts the recirc hose (large one, will need pliers to get the clip off) and the boost/vacuum hose (small one).

There is a flange connection on the d/v, bolt that to the intercooler not forgetting the gasket.

there will be adapter if needed to change the size of the boost/vacuum hose to one that fits on to the d/v. press that together, or use the supplied line to connect to the inlet manifold where the old line went (it will be very obvious).

Plug that aluminium piece into the large recirc hose that you removed off the old d/v and put a hose clip over it.

Job done. The rest of those bits in the kit are for making it a recirc valve. You obviously don't want that, so just put them in a cupboard somewhere

Job done

Bakerboy

Nice one Dave, at last someone with a non-biased logical view

Hol

iTrader: (1)

If your unsure whether you will like the woosh or not, or how differeent it will drive:

Take the recirculating pipe off the standard one,
Block the end of the pipe with a bung,
Bend some mesh over the outlet (like the stuff thsey sell for body filler) and secure it with a jubilee clip.

You have a £5.00 whoosheee dump valve. Then you can decide if the car is better with or without.

Mine is better with the standard than it was with a VTA, or two differeent design uprated recirculating valves.



BTW, the Bolt heads are 12mm, not 10mm as stated above.

RB5_245

badbaz

iTrader: (17)

Fact or fiction VTA dump valves damage engines?

Tone Loc

iTrader: (1)

The real downside to VTAs is with the standard (or any MAF ecu) it can get a little lumpy on or off the throttle, say mid corner.

In terms of overfueling.... logging a wideband sensor with VTA and recirc i found they both go rich on lift off. Why becuase they both do the same thing, sudden lift off means the ecu has openend the injectors for a certain amount of air measured going past the MAF, this air does not go into the engine at the time it has fueled for. The VTA has dumped it to atmosphere the recirc has put it back in the inlet back. This 'overfueling' i have found to be similar for both recirc and VTA..... and if somebody can prove an engine has failed due to bore wash from a VTA i'll eat my undies!

Each to they're own on these, but i think saying catastrophic engine failure will result is a complete joke.

Tony.