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Where Is The Best Place To Put A Bov On The Intercooler Piping ?

Tweaky

By Tweaky,
in Engines & Forced Induction

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Tweaky Collaborator

Tweaky

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I've been told the best place to put a BOV is on the throttle body side of the intercooler piping or as close to the throttle body as possible. The skyline i own has the BOV on the turbo side of the piping under the left wheel guard. Will this affect the performance of the car or damage the turbo/ engine over a period of time ? Is it worth while changing it to the throttle body side ?

R31Nismoid Grand Master

R31Nismoid

Posted
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Near the T/B, just like factory.

No issue having it pre-cooler however. I currently run that set-up now no issues.

I'm sure there are others as well.

RE: T/B size - pointless IMO. All it does is reduce throttle control and is proven to be no major restriction even @ 350rwkw.

Tweaky Collaborator

Tweaky

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Near the T/B, just like factory.

No issue having it pre-cooler however. I currently run that set-up now no issues.

I'm sure there are others as well.

RE: T/B size - pointless IMO. All it does is reduce throttle control and is proven to be no major restriction even @ 350rwkw.

So other words ur saying i should move it to the throttle body side. What happens when u want a atmosphere BOV which are illegal . Would u tuck it under the guard between the intercooler & engine bay ? Or would u just get a plum back system instead ?

Tweaky Collaborator

Tweaky

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He's saying it's fine where it is now, but if you had to choose where to put it then you'd put it close to the TB as possible. It's fine for now.

What do u mean by now ? Is that based on how much work has been done to the engine or power it is making ? If so what power figure would u think at changing it over , or dose this only effect throttle response ? Sorry for so many questions !

Trozzle Grand Master

Trozzle

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Posted

What Nismoid was saying, is the current positioning of your blow off valve is OK. You can leave it there.

He's running it in the same position as you are - on the turbo side - and believe me, he's running high power. If it's ok for his application, then you won't need to change it any time in the future.

What I meant, was if for any reason you have to redo all your piping, you should move it closer to the throttle body. Otherwise, just leave it.

Tweaky Collaborator

Tweaky

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What Nismoid was saying, is the current positioning of your blow off valve is OK. You can leave it there.

He's running it in the same position as you are - on the turbo side - and believe me, he's running high power. If it's ok for his application, then you won't need to change it any time in the future.

What I meant, was if for any reason you have to redo all your piping, you should move it closer to the throttle body. Otherwise, just leave it.

All is very clear now , thanks for ur patience . The reason why i asked is the car is going to a Performance workshop in the next few weeks. Car currently has a Atom BOV , but am changing it to a plum back system. Might as well relocate the BOV to the T/B side also !

R31Nismoid Grand Master

R31Nismoid

Posted
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Ye soz - where it is, as stated, is fine mate.

Im running 270/280rwkw, not a problem - 8,000km's as it is.

What recirc BOV are you using?

GTR BOV's cost for gain, are unbeatable value.

Even a single GTR BOV is good for 300rwkw or so. Much more 2 is advisable as you get a tiny bit of surge (i was when running 24psi/370rwkw on single GTR BOV)

Trozzle Grand Master

Trozzle

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Much more 2 is advisable as you get a tiny bit of surge (i was when running 24psi/370rwkw on single GTR BOV

What does this mean sorry? This may now also apply to me, as I'm going to be replacing my stock s1 GTS-T BOV with a R33 GT-R BOV very soon (just paid fellow member for it last night) and I'm running ~285rwkw @15psi. Reason I've bought it is because it's a little bit of insurance, why not have a more reliable BOV now that I'm flowing a lot more air, and I have a feeling mine is playing up as I am not making the same peak boost as I was when car was tuned (haven't even gone through a tank since)

I will be pushing ~17psi though my intake, so GT-R BOV would be preferable for me even though I'm running it ATMO lol

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
What does this mean sorry?

This:

19sec-22sec

28sec-32sec

39sec-43sec

It wasn't quite letting off all the air and I had the tiniest of surge. Most noticeable @ the 39-43sec marker when it was a full 24psi.

This was a 600HP GT30 so it was moving some air @ that boost level of course.

The return line was the external diameter of the BOV outlet as well, so it wasn't that.

Was a full size pipe, thin wall, to the T/B as well (whatever stock T/B size is).

Trozzle Grand Master

Trozzle

Posted
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Oh right, so if I'm running 17psi through the hypergear turbo, it won't leak under boost and won't have any issues letting it all out when I let off throttle - sweet :(

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Yep - it will be fine - if you get surge after full load, you just need to run the dual.

But I would hedge a bet your set-up should be ok as I rarely noticed it doing it with ~17psi.

Only 4th, full load on my car up a hill or something

Trozzle Grand Master

Trozzle

Posted
Posted

I don't entirely understand compressor surge, especially now that the BOV apparently has something to do with it while on throttle...I thought it was where the compressor was trying to feed more air through the engine than it would take, causing reversion back to the compressor wheel...and given that I thought the BOV would be closed when pressure on both sides of the TB are equal, how would it have anything to do with surge if it were a GTR BOV or GTS-T?

R31Nismoid Grand Master

R31Nismoid

Posted
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On low throttle, BOV leaks just a tad.

Thus, the excess air is "bled" off, alleviating comp surge @ lower RPM's particularly on a TT set-up.

So its stopping exactly what you say, too much air @ low RPM.

As the leak @ idle/low RPM/load (vac controlled) it stops this low end surge.

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