I just put one of those ebay MBC's on my car, its teed off my BOV and I have it on the right barbs but my bov will not work...the only way itll work is if i put my finger on the bleeder which is sucking in alot of air and making my car run funny till i plug it up, I have tried it both ways and both times its the same thing..please help

 

First off, don't tee your MBC off your blow off valve. It should be fed a pre-throttle plate boost source. Most people tee the source for the MBC from the wastegate's feed line, which generally is coming from the turbo's compressor housing [a pre-throttle plate boost source]. The way you have it set up, you are starving your BOV, and since you have it teed from a post-throttle plate source, when not in boost, you have created a vacuum leak.

So...move your MBC source to a pre-throttle plate source and you should be golden. And you really shouldn't tee anything off your BOV...it should have a dedicated boost/vac source.

 

I figured that was a stupid idea t'ing it off the bov line but I read on here that is what I should do plus it said that was an ok source in the directions for the MBC. seemed kinda retarded to me but I went with it, Thanks alot im gonna go switch that up now

 

Works great now, the car rips... thanks!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaX &raquo;</TD></TR><TR><TD CLASS="quote">First off, don't tee your MBC off your blow off valve. It should be fed a pre-throttle plate boost source. Most people tee the source for the MBC from the wastegate's feed line, which generally is coming from the turbo's compressor housing [a pre-throttle plate boost source]. The way you have it set up, you are starving your BOV, and since you have it teed from a post-throttle plate source, when not in boost, you have created a vacuum leak.

So...move your MBC source to a pre-throttle plate source and you should be golden. And you really shouldn't tee anything off your BOV...it should have a dedicated boost/vac source.</TD></TR></TABLE>

why not get boost from inside the intake manifold?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DIRep972 &raquo;</TD></TR><TR><TD CLASS="quote">

why not get boost from inside the intake manifold?</TD></TR></TABLE>

Because when using a proper MBC [one that bleeds boost] and using a post-throttle plate source, when in vacuum the vent on the MBC that bleeds boost will work backwards...it will suck vacuum and cause a vacuum leak, causing weird idle and stuff. I guess if you just have to use a post-throttle plate source, you could use some kind of check valve to prevent the MBC from seeing vacuum. TiAL also backs up this claim and says that their wastegates shoud be supplied from a pre-throttle plate source too. Both my MBC and gate are teed off my compressor housing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaX &raquo;</TD></TR><TR><TD CLASS="quote">

Because when using a proper MBC [one that bleeds boost] and using a post-throttle plate source, when in vacuum the vent on the MBC that bleeds boost will work backwards...it will suck vacuum and cause a vacuum leak, causing weird idle and stuff. I guess if you just have to use a post-throttle plate source, you could use some kind of check valve to prevent the MBC from seeing vacuum. TiAL also backs up this claim and says that their wastegates shoud be supplied from a pre-throttle plate source too. Both my MBC and gate are teed off my compressor housing.</TD></TR></TABLE>

Cool, I guess you learn something new everyday.. very good info.