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Discussion Starter #1
So we usually see the BOVs mounted 90 degrees to the pipe.

Is this High Pressure Bounced back off the TB that slammed shut, or is it additional Air being rammed in by the inertia of the Compressor wheel.

This BOV Will be Re-circulated to reduce noise and losses.

Would a Y toward the back or front be better? BOV top pointing towards the front or rear of the car?

I ask because I know it matter with WG/Manifold design.



1. What way would you point the BOV?
2. Close to the TB or the Comp Housing?
3. Boost Reference from the IM or Comp Housing?

Thanks guys
 

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It's all up to your preference or setup. Do whatever works, and both ways for questions #2 & 3 work fine.

Personally, I went with a typcial 90 degree BOV flange mounted closer to the TB than the I/C. The boost gauge I had tapped into the Edelbrock IM.
 

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Discussion Starter #3
It's not up to preference, though..

Lot's of dumb shit will work. No BOV will work.

There is an Answer.

I didn't ask about the Boost Gauge, I'm talking about the Signal to the top of the BOV Diaphragm.

To the IM, causes a Vacuum on the Top of the BOV, opening it when not in boost.

Thanks for Contributing
 

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the artist formerly known as drexelstudent11
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it's a pressure relief valve, so flow restriction and orientation don't matter in the slightest.

they're opened by the vacuum in the manifold, not by boost pressure. That's why they have a diaphragm... reference MUST be post throttle blade.
 

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ej8
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I dont think it matter to much.

Just thing about it as the air in flowing through the from turbo to motor.
When the bov opens the turbo is still pumping. but the bov opens and drops the pressure in the pipes.

rather its on a bend, y in or t in. It will go from high pressure (inside the pipe) to low pressure (the air in the bay).

I do think it would be smoother if it was on a 90 or 45 right at the tb. Since the air would be ram into the bend and then vent right out.

But as said i dont think it really matters.
 

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i think it would be better to point the bov to the throttle body and close to the throttle body to try and relieve all the pressure needed before the throttle / intake manifold but as little as possible from the charge pipes.

Edit: doing the exact opposite might be more benifitial. that way you can have the lowest pressure right by the turbo so it doesn't surge and hopefully higher pressure in the rest of the charge piping. although some bov dont do too well with the high heat right out of the turbo.

all the bov that i know about are manufactured to have the vacuum pull it open to help relieve more air. i could see getting rid of surge being really hard with it just hooked to the compressor housing.

as far as making a radiused inlet goes its probably not even close to worth it. losses over the valve would be far greater than the losses of the pipe entrance.


Just because you dont have to me nice to anyone doesn't mean you should be an asshole all the time.

this world would be even more of a shit show if every one was as much of a ass as you act online.
 

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Discussion Starter #8 (Edited)
Rather be a Smart-ass then a Dumb-ass.

How was I an ass in this thread? I even Said thanks for contributing?

Maybe you're an ass, you threw a punch first. I don't Act like an Ass.

Do or Do not! There is no try.

I should've expected as much, I was hoping to get someone with an Edjemukashun or Experience to chime in.

You just suggested one thing, then suggested the other, Then there was others on here suggesting nothing, others saying it doesn't matter. All those would receive an F on a test.

None of those answers are answers, and the most of the posts are just bullshit.

And all that proves is none of you really have the slightest clue!

I'm not talking about radiusing anything.

Also Vacuum is relative to outside pressure. You don't actually get a vacuum, anyway, it's lack of pressure on one side, both can still be positive.

Also, I said the BOV is to be Re-circed.

It does matter.

Learn something interesting, and read this, Technical Articles | Correct Wastegate Fitting | Turbosmart USA
http://www.motoiq.com/MagazineArticles/ID/1822/PageID/2651/We-Test-Synapse-Engineerings-Synchronic-Blow-Off-Valve-and-DV-Diverter-Valve.aspx


According to this, the vector is from the turbo, rather than Bounce-back from the TB..

Also, Borgwarner has Integrated Blow Off Valves, on the Compressor housing.

Looks like I got my answer,

Angle it Away from the turbo, towards the TB, Signal to the IM, Close to the Compressor


I'm done here. Feels Good.


I'm still interested in an honest, intellectual conversation.
 

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usually it is below atmosphere pressure that helps pull the bov open. My bov does a very good job staying closed if you just let off a little to drop it form 8 to around 2 psi. but it opens all the time if i let off completely at any positive pressure. although you are right in your on way cause technically its just less pressure.

i was just saying from my experience it is not wise to connect to anything other than the intake manifold.

also where did you find out that it should be "Angle it Away from the turbo, towards the TB" I would have assumed it to be the exact opposite.

angling it away from the turbo would prioritize the charge piping for pressure relief, that would mean the compressor to be more likely to surge for any given pressure in the charge pipe.
 

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Classic Man
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A BOV is a momentary pressure relief valve. A WG is not, its a continual bypass valve.

They are not the same. They dont do the same thing. They dont need to be installed the same way.


The purpose of the BOV is to momentarily relieve pressure, so the compressor can keep as much RPM as possible during a shift. That is the purpose of a blow off valve. Its purpose isnt there to save the throttle body from getting destroyed (lols) or anyhing else other than to maintain compressor RPM.

A side effect that Porsche found afterwards, was increased turbocharger life!




So what matters most to you? That your turbo spins a little bit faster when your throttle is closed, but instead you have all kinds of fucked up charge piping being routed through your engine bay, increasing the potential for lost power from pumping losses?

Or that you make the most power as possible, and still have a blow off valve T'd somewhere very close to the compressor housing?


I think the 2nd option seems like it makes the most sense to me.
 
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