GolfGTIforum.co.uk
Model specific boards => Golf mk4 => Topic started by: GTi_James on 12 April 2013, 23:27
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Hey guys,
Quick question, what are the advantages or disadvantages of reversing the DV? Read a post on vortex supplied buy a fellow forum member but it doesn't state a end result so there's a lot of smoke but no fire.
Can anyone help us?
Thanks!
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I believe you get a little bit more noise when it's reversed. But the probelem is you run the risk of boost pressure pushing the valve off its seat and prematurely venting precious boost!
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if its a piston type like forge then revered is the way its ment to be (boost pushing against bottom of the piston)
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yeh i was thinking of only doing it with a forged DV, cheers fellas
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I asked this a while ago and some people were under the impression it can be bad for the car.
I had mine reversed and it made a really horrible chirp noise........ so put it with the vac pipe inlet facing up (normal way)
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Ive been wondering this myself i plan on reversing my forge 007p an see if it makes any diff
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if its a piston type like forge then revered is the way its ment to be (boost pushing against bottom of the piston)
Whoever told you that didnt know what they were talking about.
Boost always goes into the side of the piston.
AS stated above, you have 20psi of pressure im most cases pushing the piston up off its sealing surface which causes that valve to leak.
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if its a piston type like forge then revered is the way its ment to be (boost pushing against bottom of the piston)
Incorrect.
As Chris and Beppe have stated, charge pressure should be on the side of the piston. This is part of the design that allows a fast acting DV with low spring pressure that will not leak.
By reversing it and allowing boost to act on the bottom of the piston, you're making it as crap as every other piston type BOV that needs high spring tension to remain closed, which in turn leads to it not opening under light load and compressor stall, eventually resulting in turbo damage. If you don't up the spring tension, then it's likely to bleed off boost, so you lose either way.
In theory, the pressure acting on each side of the valve SHOULD be equal and opposite, so it would remain closed, but due to pressure drops across the intercooler core and then again across the throttle body, the pressure at the charge pipe take off will always be higher than the pressure in the inlet which acts to hold the valve closed, hence it leaks.
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Interestibg read there mate. So your basically saying it installing a forge 007p in the reversed order is a big no no as it will weaken the seal and the spring which in turn will cause danage to the turbo?
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I did loads of looking into this there loads of info on tgis. End result dont do it. It fits that way for a reason. Plus it sounds gay the other way round
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Interestibg read there mate. So your basically saying it installing a forge 007p in the reversed order is a big no no as it will weaken the seal and the spring which in turn will cause danage to the turbo?
It's an either or thing really Nino, either your spring is too soft, it leaks boost, and you loose power, or your spring is too hard and you create compressor stall.
Neither are desirable.
it works 100% better when installed correctly.
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Thanks pal :)
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Well..... Yesterday i swapped mine back to the 'correct way' and i can safely say it made fook all difference boosts the same as when reversed 8/9 psi, holds it for the same amount of time if anything less than before. When ive had it reversed theres no turbo stall and theres no loss of boost
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consider as well that the standard DV placed on early Audi models (the same as VW's) were reversed initially from factory, according to another read it states customer were moaning about the flutter noise and they traced it back to the DV being to weak for its intended purpose, as a result they switched it around and got rid of the flutter, from the beginning it was suppose to be reversed but due to design flaws it was changed around, so really if you have an uprated DV and using the correct springs etc theres little difference from normal to reverse
this was found on vwvortex
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No diference here either but then my car is stock.. Maby when your tuned the way round it goes is more relavent..