1 B.O.V sur twin turbo ????

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pmbrunelle said:
The pressure can be relieved anywhere between the throttle body and the compressor discharge, with no difference in practice.

If you want to nit-pick, closer to the compressor is better, because you're trying to relieve the pressure at the compressor, not the throttle body...

Does this car have a MAF sensor? And where is it located if it has one?
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But that's not how it works. If you put the blow off valve near the compressor housing, all of the air in the pressurized section, from the blow off valve to the closed throttle body, will hit the throttle plate (because of inertia) and try to comeback the other way loosing some of it's energy. This will also create pressure waves in the pressurized section that could still lead to compressor surge.

Look at this picture of the Nissan GTR engine (two throttle bodies and two blowoff valves btw). The engineers positioned the BOVs as close as possible to the throttle bodies. But engineers don't know shit, right?


http://www.japanesesportcars.com/photos/d/35385-2/nissan-gt-r-engine.jpg
 
J'ai poster des photo de mon moteur alors pouvez vous mindiquer ou ce que je doit metre ma BOV et celle dorigine je crois savoir elle es ou et si c'est ce que je pensse ben il va avoir quelque chose a arranger ...????
 
Hellvis said:
But that's not how it works. If you put the blow off valve near the compressor housing, all of the air in the pressurized section, from the blow off valve to the closed throttle body, will hit the throttle plate (because of inertia) and try to comeback the other way loosing some of it's energy. This will also create pressure waves in the pressurized section that could still lead to compressor surge.

Look at this picture of the Nissan GTR engine (two throttle bodies and two blowoff valves btw). The engineers positioned the BOVs as close as possible to the throttle bodies. But engineers don't know shit, right?


http://www.japanesesportcars.com/photos/d/35385-2/nissan-gt-r-engine.jpg
Click to expand...

Using an example of a fast car doesn't mean anything. The location of the BOV has little effect. The engineers could have had other factors to consider, such as packaging or appearance...

For that matter, some OEM engines have their CBVs integrated in the turbo's compressor housing.

Look at this Volvo turbo:
TurboIdentification.gif


The wave argument makes absolutely no sense. By the time the BOV actually opens (it's not instantaneous) - the wave has already passed.

How fast does the wave travel? Consider that for room temperature air (and the hotter the air the higher the speed of sound), Mach 1 is roughly 345 m/s.

I'd estimate a typical BOV opening time is on the order of 100 ms.

Using those numbers, a BOV would have to be ~34.5 metres away from the throttle body to have a chance of venting the wave.
 
JOESTI said:
J'ai poster des photo de mon moteur alors pouvez vous mindiquer ou ce que je doit metre ma BOV et celle dorigine je crois savoir elle es ou et si c'est ce que je pensse ben il va avoir quelque chose a arranger ...????
Click to expand...

Yeah alright, what people sometimes do on the 1jz is they just block off the stock location and put it near the throttle plate because its easy to do, just like in that picture you posted. But it would be better if it was in the stock location and I saw some people make an adapter for that. But as pmbrunelle said, it probably won't make much of a difference anyway.

BTW, pmbrunelle, I believe that placing the throttle body closer to the throttle plate would allow air to escape before the formation of the shockwave, or at least lessen the pressure gradient. That way we don't have to go into compressible flow theory. But another thing to consider is that putting the BOV after the intercooler lets out cold air (which is not recirculated as I think the 1jz is MAP based), so the intercooler cools that air for nothing and it could cause heat soak in some situation. That must play a role when the engineers choose the location of the BOV.

Bottom line : Put it where it's easier for you, it probably won't make a difference in the end.
 
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non mais vous dites donc bin de la marde ???????? juste une est suffisante !! autre avec son 35 metres hahahaha hey big ya pas 35 metres de piping sur un char ....
 
Al4traZ said:
non mais vous dites donc bin de la marde ???????? juste une est suffisante !! autre avec son 35 metres hahahaha hey big ya pas 35 metres de piping sur un char ....
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LOL ce que tu viens d'écrire fait encore moins de sens que ce que tu pensais que pmbrunelle avait écrit... va apprendre a lire pis tu comprendras ce qu'il voulait dire... mais juste de même, il a calculer, qu'avec la vitesse d'ouverture de la BOV et la vitesse de la "wave" il FAUDRAIT 34.5 m de piping pour que la BOV puisse ouvrir avant que la "wave passe...

(P.S. asteur, est-ce vrai ou pas, je ne sais pas LOL)
 
It really depends on the brand because 1JZ have them in the piping on hot side and have only one . GTR RB26 has a two BOV on the cold side right after the I/C . Put them where you have place or where you want to "display" it dont forget that some cars dont like to have Recirc BOV swap for atmo BOV .
 
Fuck ppl on this forum are so stupid. On the RARE occasion that someone is having a remotely intelligent discussion like Hellvis and pmbrunelle, you get some fucking retarded moron like Al4traZ thinking he knows something about it but really knows nothing about anything polluting the thread without actually reading and understanding the topics being discussed. Go learn something fools
/Rant

Thanks Hellvis and pmbrunelle for the insight. Very interesting. Did you guys study this stuff or just from reading up?
 
Matt1.8T said:
Fuck ppl on this forum are so stupid. On the RARE occasion that someone is having a remotely intelligent discussion like Hellvis and pmbrunelle, you get some fucking retarded moron like Al4traZ thinking he knows something about it but really knows nothing about anything polluting the thread without actually reading and understanding the topics being discussed. Go learn something fools
/Rant

Thanks Hellvis and pmbrunelle for the insight. Very interesting. Did you guys study this stuff or just from reading up?
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I'm in my senior year of mechanical engineering.
 
Poser une question comme sa a du monde qui save meme pas comment marche un turbo tu vas avoir de la marde comme réponse.
Personnellement je te conseil de rester avec le setup que tu as la mais ces mon oppinion.
 
winter_suck said:
Poser une question comme sa a du monde qui save meme pas comment marche un turbo tu vas avoir de la marde comme réponse.
Personnellement je te conseil de rester avec le setup que tu as la mais ces mon oppinion.
Click to expand...

De ce que j'ai compris, c'est que c'est pas facile de poser une BOV aftermarket dans la position stock sur ce char là. C'est là que réside son problème.

Personellement, je vois pas l'interêt de changer la BOV à moins qu'elle soit une source de problème. Ça doit plutôt être pour le...v00000mmmpssssst... que tant de gens recherchent.
 
Matt1.8T said:
Fuck ppl on this forum are so stupid. On the RARE occasion that someone is having a remotely intelligent discussion like Hellvis and pmbrunelle, you get some fucking retarded moron like Al4traZ thinking he knows something about it but really knows nothing about anything polluting the thread without actually reading and understanding the topics being discussed. Go learn something fools
/Rant

Thanks Hellvis and pmbrunelle for the insight. Very interesting. Did you guys study this stuff or just from reading up?
Click to expand...

regarde mon ti papoute, sa fais bin plus longtemps que je suis ici que toi et sa fais probablement plus longtemps que toi que je joue dans la mécanique donc je comprends très bien ce qu'il voulais dire, tu n'a rien dit de pertinent dans ton post concernant le sujet du thread alors a ta place j'en dirai pas plus fanboy.:cry:
 
Hellvis said:
De ce que j'ai compris, c'est que c'est pas facile de poser une BOV aftermarket dans la position stock sur ce char là. C'est là que réside son problème.

Personellement, je vois pas l'interêt de changer la BOV à moins qu'elle soit une source de problème. Ça doit plutôt être pour le...v00000mmmpssssst... que tant de gens recherchent.
Click to expand...

exactement sa sert a rien appart faire PPPHSSSSSS :p mais je l'ai eu gratuite alors pourquoi pas la pauser ... :D et jai demander a un gars qui a un 2jz-gte et lui la pauser sur le piping d'intercooler juste avant les turbo ...
 
Al4traZ said:
regarde mon ti papoute, sa fais bin plus longtemps que je suis ici que toi et sa fais probablement plus longtemps que toi que je joue dans la mécanique donc je comprends très bien ce qu'il voulais dire, tu n'a rien dit de pertinent dans ton post concernant le sujet du thread alors a ta place j'en dirai pas plus fanboy.:cry:
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1-Stop watching so much tete a claque(ti-ppapoute)
2-Le rapport de la date d'inscription a aucun rapport.
3-Tu "joue" en mécanique, j'ai un DEP en mécanique
4-Mon remerciement envers les 2 membres ainsi que ma question à ces 2 membres ont beaucoup plus leurs places que ton commentaire.
5-Fuck yes I'm a fanboy but once again, that has absolutley nothing to do with the topic and is nothing but an extremely feeble attempt at an insult.
6-I actually have a turbo with a BOV so I'm in a much better position to speak on the subject that you are.
k
thx
bye

PS sorry for polluting.
 
Matt1.8T said:
1-Stop watching so much tete a claque(ti-ppapoute)
2-Le rapport de la date d'inscription a aucun rapport.
3-Tu "joue" en mécanique, j'ai un DEP en mécanique
4-Mon remerciement envers les 2 membres ainsi que ma question à ces 2 membres ont beaucoup plus leurs places que ton commentaire.
5-Fuck yes I'm a fanboy but once again, that has absolutley nothing to do with the topic and is nothing but an extremely feeble attempt at an insult.
6-I actually have a turbo with a BOV so I'm in a much better position to speak on the subject that you are.
k
thx
bye

PS sorry for polluting.
Click to expand...
pass de probleme :p
 
@ Joe
Comme l'a été mentionné ci-haut, souvent les ingénieurs le place à des endroits stratégiques (pour raisons X, Y, Z) alors mettre ton BOV à la place de celui d'origine(qui parfois se trouve à être un DV) ne fera aucun tort d'après moi et est aussi ce qui a de plus facile.
 
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