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Discussion Starter #1
until im able to get my forged bov i was wanting to remove the hose from the valve to the air intake, and plug the intake. that would cause my bov to vent into the atmos rather than intake right? anyone see any problem with me temporarily doing this? lemme know!
 

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Yeah, that would do it. However, when air is not blowing off into the atmosphere, debris can get sucked up and could possibly cause a lot of damage.

If you really really need that sound and can't wait, go to you local auto parts dealer and buy a crank case vent filter that is approximatly the same diameter as the pipe you just removed. Then go to a hardware store and buy a bit of pcv to screw both ends down. And tada, a ghetto bov for like $5.

I did the above project on some idle Saturday and by Sunday, I put it back to stock. I have since replaced the stock with a Forge BPV, the legit way.

Also, to plug the intake, I found that the lid of a two liter bottle of soda fits almost perfectly, I also added some tape just to be sure.
 

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Just be sure that when you do this, remember it is not a permanent BOV replacement. A BOV still has an important purpose of holding down the boost. I know it is just a quick fix until you get a Forge, but keep in mind there is something to gain from it. Have fun.
 

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Discussion Starter #4
comtrang said:
Just be sure that when you do this, remember it is not a permanent BOV replacement. A BOV still has an important purpose of holding down the boost. I know it is just a quick fix until you get a Forge, but keep in mind there is something to gain from it. Have fun.
i realize i should get the right part, but im not getting rid of the current blow off, just redeirecting the waste. would it still not hold boost down?
 

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lifelesslived17 said:
i realize i should get the right part, but im not getting rid of the current blow off, just redeirecting the waste. would it still not hold boost down?
Yeah, I understand what you're doing, I'm not saying there's anything wrong with it. Yes, your current bypass (you do have the stock one, correct) valve will hold the boost but if you start raising it, it may no longer be able to hold it. Even now, if you're still running a stock boost level, once you're in the peak area of it, a Forge will hold it down much better. There's nothing wrong with what you're doing at all, I was just saying when you change, don't forget that the Forge does have a purpose [other than making a cool sound] so keep it in mind.
 

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comtrang said:
Yeah, I understand what you're doing, I'm not saying there's anything wrong with it. Yes, your current bypass (you do have the stock one, correct) valve will hold the boost but if you start raising it, it may no longer be able to hold it. Even now, if you're still running a stock boost level, once you're in the peak area of it, a Forge will hold it down much better. There's nothing wrong with what you're doing at all, I was just saying when you change, don't forget that the Forge does have a purpose [other than making a cool sound] so keep it in mind.
Well the stock Bosch works just fine with higher boost also.
Check the "beyond 500bhp"-thread and I believe Vigge is still running the stock blow-off.
 

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I think the problem with dumping to air with the stock item is simply that at idle it will sit open with a risk of sucking in foreign objects; so to ensure this is safe a little crank case breather type device with a mini air filter attached to where the return hose went is the common sense safety device.
 

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Oh, really? Why does that happen? I've never heard that before...
Not that I'm doubting you or anything, I've just never heard of that.
 

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No answer for the torque, but my stock bpv died quite quickly once I raised the boost. I think it lasted maybe a month or two. When they fail they make a funny 'hooooot' noise a bit like an owl. I recommend driving with a failed bpv for a while, as it it funny as hell.
 

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stamonkey said:
No answer for the torque, but my stock bpv died quite quickly once I raised the boost. I think it lasted maybe a month or two. When they fail they make a funny 'hooooot' noise a bit like an owl. I recommend driving with a failed bpv for a while, as it it funny as hell.
Hahaha, I almost sorry I didnt try that. :lol:
 

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Yeah, I'm really not sure how anyone can raise boost and not get the hooting sound..
Perhaps Vigge still does run a stock bpv, I don't recall, but he also has a Viggen. I'm not sure if a Viggen's stock bpv is the same as an NG900's.
 

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lifelesslived17 said:
i am also curious as to why i would loose torque, care to break down the physics behind this for me?
I don't want to speak for boxman because I may be wrong, but what I think he means is that the turbo will take longer to spool up because it doesn't have the recirculatory air keeping it spinning.
 

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KSpark said:
I don't want to speak for boxman because I may be wrong, but what I think he means is that the turbo will take longer to spool up because it doesn't have the recirculatory air keeping it spinning.
Yeah, I had something in mind along those lines, too...
But what about when using a non-recirculating [blow off] valve? Isn't that sorta the same thing?
 

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comtrang said:
Yeah, I'm really not sure how anyone can raise boost and not get the hooting sound..
Perhaps Vigge still does run a stock bpv, I don't recall, but he also has a Viggen. I'm not sure if a Viggen's stock bpv is the same as an NG900's.
From what I remember of a conversation I had with Nick T a long time ago, he said that the viggs did have a different valve.
 

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I have done (what i think is) the same thing that you have. Merely disconnected the tube from the bpv to the intake and plugged it. I too have an atmospheric bov on the way, but this is just too much fun to wait for :cheesy:

Im not really sure that the air the bpv recuirculates is really enough to feel a faster spool with. After all my "seat of the pants" horsepower rose a ton (i know im not faster, but i sure as hell feel/hear it)

I'll check on the "open while idle" idea tomorrow before i head to school, and post with my findings.
 

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low end torque is lost as a result in air entering the dump valve under vacuum, this air upsets the air stream from the filter box, which Saab spent many $$$$ designing ;) this turbulence reduces the amount of air that reaches the engine giving low torque until boost builds and the dump valve closes.

that said there will be folks on here who are going to argue with this point :roll:
 

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boxman said:
low end torque is lost as a result in air entering the dump valve under vacuum, this air upsets the air stream from the filter box, which Saab spent many $$$$ designing ;) this turbulence reduces the amount of air that reaches the engine giving low torque until boost builds and the dump valve closes.

that said there will be folks on here who are going to argue with this point :roll:
Wow, no thats stupid...///

haha, that makes sense, but its a turbo car so i have a tendency to rely on higher revs and boost for speed.
 
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