venting bov into maf intake stream?

[OsoSlo z28]

get a stand alone system...then no worries.

[marshmallow15]

wayy too expensive and advanced for me. im dont want the whoosh that badly. maybe if i had the extra money to throw around though.

[BATTOSAI]

It is no problem if it´s installed before the maf, as it ejects the pressurized air before it´s measured. This only works in blow-through maf's.

[OsoSlo z28]

but it's not recommended to use the maf in a boosted atmosphere. it can affect the air reading when under boost and possibly damage the maf.

[marshmallow15]

hey thats a good idea batt.

[rikymaru]

Sorry man. That idea of "venting before the intake" would not work at all. The whole point of a BOV is to let off the excess air left over that is unspooled when you SHIFT. And this excess air is sorted out by the ECU depending on what your waste gate is set to let out (a mechanical boost gauge changes this but it is still the same concept) To vent it before the intake wouldn't make any sense since there is not any pressure built in the first stage of intake.<P>I hope I got that across without sounding too confusing/insane ^_^

[pelado]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by rikymaru:<BR><STRONG>I hope I got that across without sounding too confusing/insane ^_^</STRONG><HR></BLOCKQUOTE><P>Uh, no. You weren't very successful.<P>MAF --> Turbo -> BOV -->Intercooler-->Intake<BR>.......^__________| <P>Is this how it's supposed to work?<p>[ November 14, 2002: Message edited by: pelado ]

[maldo]

no.<P>Filter-->MAF-->turbo-->intercooler-->BOV-->TB-->Intake Manifold.

[marshmallow15]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by maldo:<BR><STRONG>no.<P>Filter-->MAF-->turbo-->intercooler-->BOV-->TB-->Intake Manifold.</STRONG><HR></BLOCKQUOTE><P>aww man...i guess a haltech is back in my f/i wishlist.

[BATTOSAI]

I wanted to say:<BR>Filter-turbo-BOV-MAF-TB<p>[ November 15, 2002: Message edited by: BATTOSAI ]

[pelado]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by maldo:<BR><STRONG>no.<P>Filter-->MAF-->turbo-->intercooler-->BOV-->TB-->Intake Manifold.</STRONG><HR></BLOCKQUOTE><P>OK, so the BOV is on the downstream side of the intercooler, I don't see what difference THAT makes but whatever.<P>The BOV vents back between the MAF and turbo then, correct? It would seem to be a waste of time otherwise.

[OsoSlo z28]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by pelado:<BR><STRONG><P>OK, so the BOV is on the downstream side of the intercooler, I don't see what difference THAT makes but whatever.<P>The BOV vents back between the MAF and turbo then, correct? It would seem to be a waste of time otherwise.</STRONG><HR></BLOCKQUOTE><P>right, if you're using a bypass valve or venting the bov back into the system, it goes between the turbo and maf so the air isn't "re-read".

[rikymaru]

err...yea I was.<P>MAF --> <P>You are going to vent from the MAF?! I get it now! PLug a hole in the K+N filter, get a tube to run through it and then it will vent as the air is taken in before the ECU can calculate That's what I meant by venting in the first stage of intake wouldn't work; no pressure. The BOV has NOTHING to do with the the first stage of intake. It actually has nothing to do with the 4 stages of the miller cycle; it's all based on the the RPM you shift at and of course the BOV itself.<P>A blow off valve vents excess turbo boost to the atmosphere. Simple as that. What determines what is "excessive?" Your RPMs you shift at and the BOV (the waste gate does a little something too but it's ntohing to think about). <P>"Wait...I can vent into the first stage of intake. The air is there so why not vent it?"<P>Again, that completely demeans the point of the valve: to blow off air. Without a BOV your throttle plate would cose and create a wall to the pressurized air wooshing out of the turbo. The air (boost) would smash this plate and the air would pile up as it hits the plate. <P>"Well, if the air is trapped, where will it go?!"<P>Besides being a shock to the turbo, it would basically cause the turbo to come to a stop and, in extreme cases, start spinning in reverse. Meaning? Slower spool up time and the short, shot life of a turbo.<P>BTW, I always misuse the definition because EVERYONE else does. A compressor bypass valve is what almost all stock factory cars have. It vents the excess air into the intake stream. A true BOV (blow off valve) vents it to the atmosphere. But everyone refers to a CBV as a BOV. Do you hear anyone call it a compressor bypass valve? That's what I thought :p

[rikymaru]

BTW, I'm not trying to sound like a ****. I just don't want people ruining their cars for a cool noise. If you really like the noise then get an HKS BOV. They are $180 and are quite loud even when not vented. My car has a small stock one (stable as hell though) but I can hear it when I'm driving and people can hear it next to me.<P>Filter-->MAF-->turbo-->intercooler-->BOV-->TB-->Intake Manifold.<P>Yep, Maldo was on it. That is the correct way it works. Wonder why a VPC lets you vent? That setup becomes<P>Filter-->VPC-->turbo-->VPC reads turbo output-->intercooler-->BOV-->VPC compensates for the air that is vented-->TB-->Manifold<P>At the same time it also has add on programs that let you manage the injectors and fuel control. The VPC has two major downfalls: The cost (I hear its quite expensive) and adjustment. If your ambient climate changes by 20 degrees people say the cars idle goes to **** and it has to be recorrected. Basically, I wouldn't get one if you live in a tropical type place that goes from sunny 80 degrees to raining 64 degress in the same day.<P>[ November 15, 2002: Message edited by: rikymaru ]<p>[ November 15, 2002: Message edited by: rikymaru ]

[jaydog5678]

The VPC is around 900 and you must get the fuel computer that accompanies it. For a few more Franklins, get a Standalone and have complete control.. thats the way to go.<p>[ November 15, 2002: Message edited by: jaydog5678 ]