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Did anyone here install a blow-off valve on their R? I haven't heard any talk about it, and was wondering if they are even beneficial for the car. I know they make that cool chirping sound between shifts, but do they enhance performance whatsoever?
 

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Re: Blow-off valve? (jdog)

I asked this question 2 months ago, too.<br>I was told no, no, no, no, no. <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0">
 

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this was just discussed a few days ago...scroll down and read...<p>a blow off valve will decrease lag on a turbo car that does not previously have one installed, but simply replacing the one you have on the car already won't really help increase performance
 

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Re: (phuz)

A blowoff valve is made to take the extra pressure and dispense it. (thus the chirping) We do not have one. Our cars are made to "hold" that pressure so the next gear has enough boost to have little to no "lagg".With a blow off valve, all of that pressure has to build up again. Thus the "lagg" that is noticed with a blow off. I would not trade "lagg" for a nice chirping sound. I hope this helps, Rick
 

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Re: (MASH)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>MASH</b> »</i></TD></TR><TR><TD CLASS="quote"> A blowoff valve is made to take the extra pressure and dispense it. (thus the chirping) We do not have one. Our cars are made to "hold" that pressure so the next gear has enough boost to have little to no "lagg".With a blow off valve, all of that pressure has to build up again. Thus the "lagg" that is noticed with a blow off. I would not trade "lagg" for a nice chirping sound. I hope this helps, Rick</TD></TR></TABLE><p>We have one...<p>A Blow off Valve is exactlt doing what you are telling here only with the term BOV a free to air type of pressure release is often meant instead of what we call a CBV, Compressor Bypass Valve.<br>The difference is that instead of releasing free to air, outside the intake system, the pressure will be released back in to the intake system before turbo compressor.<br>The reason for this setup is because the R uses an air metering system so it needs to know how much air is in the system.<p><br>
 

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The need for a BOV or simular device is to release all pressure in the charge pipe when the throttle is closed ie gear changes to stop the trapped compressed air in the charge pipe from stalling the turbine. Thus allowing the turbine to keep (free) spinning until boost is required again ie throttle is depressed.
 

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Re: (JonnyEnglish)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>JonnyEnglish</b> »</i></TD></TR><TR><TD CLASS="quote">The need for a BOV or simular device is to release all pressure in the charge pipe when the throttle is closed ie gear changes to stop the trapped compressed air in the charge pipe from stalling the turbine. Thus allowing the turbine to keep (free) spinning until boost is required again ie throttle is depressed.</TD></TR></TABLE><p>Correct me if I'm wrong, but I thought it was more to prevent unusually high intake manifold from blowing it up (or more correctly, blowing out a seal or something like that) when the throttle is slammed closed, not to keep the turbo spinning.
 

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the stock CBV instead of venting the pressurized air to the atmosphere, reroutes the pressurized air back into the airtract. <p>you could always use a recirculatory 50/50 atmosphere/intake tract BOV like i have on my wrx.<br>there are a few manufacturers that make straight up 50/50 or adjustable BOV's 25/75, 50/50,75/25
 

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Re: (yerrow)

Sounds reasonable but it really is to prevent stalling the turbine and I guess a by product it would alleviate excess pressure as you explained. Having said that though the engine and all associated accessories would have been tested and checked for those pressures.<BR><BR>
<i>Modified by JonnyEnglish at 5:56 PM 3-23-2006</i>
 

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Re: (JonnyEnglish)

I believe our R's have a waistgate not a blow off. I could be wrong. <IMG NAME="icon" SRC="http://www.vwvortex.com/zeroforum_graphics/screwy.gif" BORDER="0">
 

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Re: (JonnyEnglish)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>JonnyEnglish</b> »</i></TD></TR><TR><TD CLASS="quote">Sounds reasonable but it really is to prevent stalling the turbine and I guess a by product it would alleviate excess pressure as you explained. Having said that though the engine and all associated accessories would have been tested and checked for those pressures.</TD></TR></TABLE><p>According to Wikipedia, we're both right<p><I>This excess pressure could potentially cause damage to the turbocharger's impeller and may also slow or even stop it, thus causing turbo lag when the throttle is pressed again.</I><br> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0">
 

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Re: (MASH)

WOOOWWWWWWWW I don't even know what to say. There is SOOOOOOOOOO much mis information in this thread sans yerrows, andJohanns post. Bov and waste gate are two completely different things. See here:<br> <IMG SRC="http://volvospeed.com/Pics/Review/tial.jpg" BORDER="0"> <br>The one on the left is a BOV and the one on the right is an EXTERNAL wastegate. Your car has both a bypass valve(just like a bov but vents internally, not externally or atomspherically). A bypass valve, bov, diverter valve, etc.. releases excess pressure WHEN the THROTTLE PLATE closes. This prevents backspin on the impellar and reduces turbo lag.
 

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Blot and I have BOVs in our cars...we also have wastegates <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"><p>The stock R will have a wastegate and a BOV that recircs.<p>Blot's system recircs while mine vent to atmosphere. Interestingly, when Blot tried to vent to atmosphere on his 04R, he gets error messages while my 05R has no such problems.
 

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Re: (DisCom)

<IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0">
 

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Re: (MASH)

many same cars of different years/ecu's will respond differently to atmospheric/recirculation BOV's tell him to try an adjustable one
 

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Re: (needsdecaf)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>needsdecaf</b> »</i></TD></TR><TR><TD CLASS="quote">Correct me if I'm wrong, but I thought it was more to prevent unusually high intake manifold from blowing it up (or more correctly, blowing out a seal or something like that) when the throttle is slammed closed, not to keep the turbo spinning.</TD></TR></TABLE><p>A BOV or BYpass valve does NOTHING to prevent excess boost. Its ONLY purpose is to release the trapped air when the throttle plate(s) is closed to prevent a stall of the compressor wheel, as per johnnyenglish's explanation.
 

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Re: (phuz)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>phuz</b> »</i></TD></TR><TR><TD CLASS="quote"><p>A BOV or BYpass valve does NOTHING to prevent excess boost. Its ONLY purpose is to release the trapped air when the throttle plate(s) is closed to prevent a stall of the compressor wheel, as per johnnyenglish's explanation.</TD></TR></TABLE><p>Where did I say that it prevented excess boost? <p>You are basically saying what I was trying to put into words. <p>
 

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Re: (needsdecaf)

Yeah what he said <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0">
 
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