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Discussion Starter · #1 ·
Is it OK to use an open Blow off valve instead of the recirculation one? I want to start using one again when I get the R, but I don't want to the MAF or anything.
 

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Re: Turbo XS Type RFL (phuz)

THis has been talked about before. It is my understanding that chaning the R from a recirculating BOV to an atmospheric BOV is not trivial. I am sure people can give you more information, but it wasn't worth it to me.
 

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Re: Turbo XS Type RFL (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">Is it OK to use an open Blow off valve instead of the recirculation one? I want to start using one again when I get the R, but I don't want to the MAF or anything.</TD></TR></TABLE>I have one on my car with my hard pipes sounds great but really with the stock turbo serves no purpose except the noise.
 

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Discussion Starter · #5 ·
A blow off valve will serve a purpose for any size turbo; its purpose is to release the charge pressure as soon as the throttle closes so that there is no back pressure on the compressor fins forcing a reverse in direction, so anyone can benefit from it <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/smile.gif" BORDER="0"><br>
 

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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">A blow off valve will serve a purpose for any size turbo; its purpose is to release the charge pressure as soon as the throttle closes so that there is no back pressure on the compressor fins forcing a reverse in direction, so anyone can benefit from it <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/smile.gif" BORDER="0"></TD></TR></TABLE>I know what it does but there is no way to stop the stock bypass valve unless you fab up a piece of metal to block off the stock one. The stock bypass valve is on the stock turbo housing.
 

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Discussion Starter · #7 ·
oh wow....didn't know that. I'm used to my saab which had a factory bypass which came directly off the charge piping.<p>did you block yours off?
 

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Re: (phuz)

No I have both working together right now as my future plans are to change to a bigger turbo and external wastgate and all that fun stuff but then I will also be upgrading to a HKS racing type 2 blow off valve as the turbo xs can loose pressure over 25psi from what i hear. I plan on running a little more then that once my motor is built and all.
 

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Re: Turbo XS Type RFL (phuz)

do you have pictures of how yours is mounted? im thinking aobut getting one and getting it installed; also how did you make both the CBV AND the BOV to work together?
 

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Discussion Starter · #10 ·
allow me to clear up the misconception of the way the turboXS RFL BOV works. <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/smile.gif" BORDER="0"><p>Under some circumstances, the vacuum line that is connected to the BOV has a check valve so that it can only see vacuum when the throttle is closed, but will never see boost; this means that there is standard atmospheric pressure on that side, while there is boost coming in from the charge side; in this circumstance, yes, anything over 25psi will force piston open, and will leak boost; HOWEVER, if you do not use a check valve and you allow boost to come through the vacuum line up to the BOV and on the charge side, there will be an equilibrium on the piston and no amount of boost will push the piston either way, but when the throttle is closed, you still have boost in the charge side, but now you have vacuum on the opposite side, so you have a push force on one side and a pull on the other which causes it to open.<br>I examined this when I was using the Type-H RFL on my saab several years ago. <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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