How to Make a Loud BOV Quiet.
01-24-2009, 09:22 PM
#1
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How to Make a Loud BOV Quiet.
Wrap that bitch in foam.
It's a lot quieter now. Just easing around town without boosting, I don't hear it. Before you'd hear it no matter what. If I get on it some and make a few PSI, I sometimes here it, but barely. Probably not audible from outside the car. Full boost, you hear it, but it's not much louder than at a few PSI. I'm gonna try wrapping a little piece of metal around the foam where the BOV vents tomorrow. This may make it quieter and will help keep from blowing all the foam out. Currently have 3 zip ties holding the foam.
The intake is now 10x louder than the BOV. Working on a solution there too.
It's a lot quieter now. Just easing around town without boosting, I don't hear it. Before you'd hear it no matter what. If I get on it some and make a few PSI, I sometimes here it, but barely. Probably not audible from outside the car. Full boost, you hear it, but it's not much louder than at a few PSI. I'm gonna try wrapping a little piece of metal around the foam where the BOV vents tomorrow. This may make it quieter and will help keep from blowing all the foam out. Currently have 3 zip ties holding the foam.
The intake is now 10x louder than the BOV. Working on a solution there too.
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01-24-2009, 09:59 PM
#7
How to Make a Loud BOV Quiet.
Wrap that bitch in foam.
NOT...you probably reduced the flow by a good amount. BOVs or BPVs need to be fast-acting in order to shift huge quantities of air before the charge line between the compressor and throttle body shoots up in pressure, thus causing a reversal of flow and the resultant turkey gobble.
Use a bypass valve if you want a quiet BOV. If its good enough for Formula 1 and every single OEM or factory racecar ever made, its good enough for you. subaru has the best OEM bypass valve and you can have one for $20 if you look.
Wrap that bitch in foam.
NOT...you probably reduced the flow by a good amount. BOVs or BPVs need to be fast-acting in order to shift huge quantities of air before the charge line between the compressor and throttle body shoots up in pressure, thus causing a reversal of flow and the resultant turkey gobble.
Use a bypass valve if you want a quiet BOV. If its good enough for Formula 1 and every single OEM or factory racecar ever made, its good enough for you. subaru has the best OEM bypass valve and you can have one for $20 if you look.
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01-24-2009, 10:02 PM
#8
with his intake consisting of a 6" (just a guess) pipe I seriously doubt recirculating the air back there will make it any quieter...that is unless he'd extend the intake and install the stock airbox or something.
is that a heat shield you are working on in the first picture Pat?
is that a heat shield you are working on in the first picture Pat?
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01-24-2009, 10:08 PM
#11
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Basically I couldn't recirculate it. At least, not easily. The intake is basically a filter on the turbo, with no room for anything else.
Yes I'm going for the sleeper look, and sound matters too.
Whether it hurt flow or not... I really don't care. This turbo surges/flutters (whatever it's called) when I shift below 3500. That is, until the BOV finally stops dragging it's *** and opens. Still does the same thing as before with the foam, only now I hear "flutter-flutter-silence...". I should probably get a softer spring for the BOV so it will open sooner.
I'm gonna wrap the air filter in foam too after I build enough heat shields to feel safe doing it. Don't care if that hurts performance either. I want a quiet, reliable, fast car. In that order.
Yes I'm going for the sleeper look, and sound matters too.
Whether it hurt flow or not... I really don't care. This turbo surges/flutters (whatever it's called) when I shift below 3500. That is, until the BOV finally stops dragging it's *** and opens. Still does the same thing as before with the foam, only now I hear "flutter-flutter-silence...". I should probably get a softer spring for the BOV so it will open sooner.
I'm gonna wrap the air filter in foam too after I build enough heat shields to feel safe doing it. Don't care if that hurts performance either. I want a quiet, reliable, fast car. In that order.
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01-24-2009, 11:54 PM
#16
I think while browsing through FM's 700 some-odd (probably more now) pictures they have in their album, I saw a few of a car with what looked to be a large chunk of foam that was carved hollow with holes cut into it for air flow placed over the filter, and that it did a great deal in quieting the intake.....At least I think it was in FM's photos...
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01-25-2009, 12:08 AM
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I think while browsing through FM's 700 some-odd (probably more now) pictures they have in their album, I saw a few of a car with what looked to be a large chunk of foam that was carved hollow with holes cut into it for air flow placed over the filter, and that it did a great deal in quieting the intake.....At least I think it was in FM's photos...
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that is what you get when you try to go against the flow in a world filled with ricers
