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Old 04 Feb 2007, 06:10 PM   #1 (permalink)
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Red face dump valve

Please help, I have a 96(p)wrx jap import and was thinking about a dump valve.Problem is i'm new to scoobies and dont know which one I need or where it goes can anyone enlighten me???
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Old 04 Feb 2007, 10:53 PM   #2 (permalink)
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It really depends on what sort of dump valve you want mate? Your Scoob will have a dump valve fitted as standard and unless its leaking you really won't see a huge benefit of fitting an aftermarket one. However should yours be leaking or should you just feel the need then you can fit one of 2 types of dump valve. The first is a recirculating dump valve which is a direct fit for the factory one you have at the moment. Basically the air that is discharged when coming off the throttle is recirculated within the induction system. These types of d/v's are generally quiet and the car very rarely has any running issues if you fit an uprated one. I had a Forge recirc fitted to my Subaru and it did seem to help the amount of lag between gears etc. but in my case my original d/v was leaking!

The other type of d/v available to you is a Vent to Atmosphere or whats commonly know as VTA. These give the tsssssssst sound when coming off the throttle. There have been countless threads across Motoring forums on the WWW about the benefits and pitfalls of fitting a VTA from poor idling to overfuelling etc. Each car is however very different so whilst one Scoob might run poorly with a VTA fitted another might run fine. The VTA basically discharges the boost pressure to atmosphere rather than recirculate it. I have tried many VTA's over the time and I have to say that the HKS SSQV is the best one in terms of performance and noise.

I hope this helps a bit and apologies for the length of the reply
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Old 05 Feb 2007, 07:11 AM   #3 (permalink)
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Quote:
or where it goes

Dump valve location.

http://www.subaru-impreza.org/images...engine/1-7.htm
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Old 05 Feb 2007, 06:11 PM   #4 (permalink)
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from what i can gather the only one really worth watching out for mate is the Bailey VTA, I`ve known of a few people who had no end of problems with them.

When i changed my dumpvalve recently I found that the OE plastic dumpvalve was broken which was causing the car to boost only to 0.6 bar instead of 0.9 so it made a huge difference when i changed it.
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Old 05 Feb 2007, 06:55 PM   #5 (permalink)
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Mine must be the one that works then lol been on 2.5yrs(23,000miles) no problems.(bailey VTA)

Though will be getting a turbosmart one i think when i fit a frontmount(eventually)
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Old 05 Feb 2007, 06:57 PM   #6 (permalink)
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must have been lucky then Dave
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Old 05 Feb 2007, 07:01 PM   #7 (permalink)
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lol makes a change,5th gear going at 33k miles werent that lucky mate pmsl
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Old 05 Feb 2007, 07:05 PM   #8 (permalink)
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doesn`t sound too lucky to be fair, no wonder you`re always at home polishing it then

as far as I know mine`s still on the original box at 47000 and would hope it stays that way for a while, or at least until I can afford a 6 speed
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Old 05 Feb 2007, 07:12 PM   #9 (permalink)
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Few ppl ive spoke to reckon the 6spd spoils the drive a bit-know there a strong box but i quite like the ratios of the 5spd suits my driving style if/when i get to the point where i need a stronger box reckon i`d buy a sti6 box an have it rebuilt before going in-i really dont need a 6th gear.(though do expect the sti`s box ratios to be different)
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Last edited by uk dave; 05 Feb 2007 at 07:25 PM.
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Old 05 Feb 2007, 07:14 PM   #10 (permalink)
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Fair comment mate, I`m only going for the 6 speed for the strength of it more than anything, Can`t use 5th over here most of the time
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