Pointless? - Page 2 - Subaru WRX Forum
Reply
 
LinkBack Thread Tools Display Modes
#16 Old 10-13-2004, 11:32 AM
 
IBAUCLAPlaya's Avatar
 
Join Date: Oct 2003
Location: Ohio
Posts: 3,488
Images: 8
IBAUCLAPlaya is known to be trustworthy and helpful IBAUCLAPlaya is known to be trustworthy and helpful
Send a message via AIM to IBAUCLAPlaya
Yeah I hear peoples stock bypass valve from outside the car if they remove the stock airbox. I think the SRI intensifies the sound though.
IBAUCLAPlaya is offline  
Sponsored Links
Advertisement
 
#17 Old 10-13-2004, 11:36 AM
WRXtuners Member
 
Bullit's Avatar
 
Join Date: Aug 2004
Location: Maryland
Posts: 356
Bullit is an unknown
I have a CAI, and come to think of it. That thing is pretty loud. The BOV sounds damn good to be stock.
Bullit is offline  
#18 Old 10-13-2004, 03:48 PM
WRXpert
 
dumdum's Avatar
 
Join Date: Sep 2004
Location: Virginia
Posts: 2,800
Images: 12
dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention
Quote:
Originally Posted by Cosmo
I have never seen any proof that they will waste your gas or make your car slower, but they won't make it any faster.
http://www.spdusa.com/blow-off_valves.htm When you divert the air into the atmosphere in a MAF vehicle the car will run overly rich(super rich!) because of the fact that the MAF has already metered that mass of air and now it is not present.The ECU cannot respond fast enough.This is not a problem in speed density cars because the air is metered from the manifold.Plus the divertor valve plumbing the air back into the turbo inlet keeps the turbo spooled durring the shift and the charge pipes pressurized leading to less lag.The blake smoke i was refering to is raw unburnt fuel blowing out the tail pipe.Pretty sure that would be a waste of fuel.

Homebrewed tuned with Opensource!
dumdum is offline  
#19 Old 10-13-2004, 04:06 PM
WRXtuners Member
 
Cosmo's Avatar
 
Join Date: Dec 2002
Location: Virginia
Posts: 4,591
Images: 15
Cosmo is known to be trustworthy and helpful Cosmo is known to be trustworthy and helpful
Send a message via AIM to Cosmo
Quote:
Originally Posted by dumdum
http://www.spdusa.com/blow-off_valves.htm When you divert the air into the atmosphere in a MAF vehicle the car will run overly rich(super rich!) because of the fact that the MAF has already metered that mass of air and now it is not present.The ECU cannot respond fast enough.This is not a problem in speed density cars because the air is metered from the manifold.Plus the divertor valve plumbing the air back into the turbo inlet keeps the turbo spooled durring the shift and the charge pipes pressurized leading to less lag.The blake smoke i was refering to is raw unburnt fuel blowing out the tail pipe.Pretty sure that would be a waste of fuel.
In order for that arguement to hold true, engines would have to function differently. What other things happen in order for a BOV to function? You let off the gas, which closes the throttle body. That forces the air out the BOV or bypass valve. That air has already passed by the MAF sensor, however either way it's not going into the engine, so that "extra fuel" is not mixing with any air anyways. If somehow the bypass valve diverted the air into the intake manifold, that arguement would be true. But, since it diverts it back into the intake tube before the turbo (recirculating) that air isn't going into the engine anyways.

And, a BOV is actually better at keeping the turbo spooled. Backpressure that builds up in the intercooler slows the turbo down. That backpressure usually isn't much of a concern because most of it is being drawn into the intake manifold. But, once the throttle body closes, the pressure inside the intercooler raises significantly. That backpressure makes it harder for the compressor wheel of the turbo to spin, thereby slowing it down. The stock bypass valve recirculates it into the front of the turbo again, which helps, but it is harder for the turbo to spin through that already-compressed air. The BOV relieves pressure inside the intake to allow the turbo to spin freely.

Well, that's my take on it anyways....
Cosmo is offline  
#20 Old 10-13-2004, 05:16 PM
WRXtuners Member
 
Quack's Avatar
 
Join Date: May 2004
Location: Ohio
Posts: 451
Images: 7
Quack is more helpful than not
Quote:
Originally Posted by dumdum
http://www.spdusa.com/blow-off_valves.htm When you divert the air into the atmosphere in a MAF vehicle the car will run overly rich(super rich!) because of the fact that the MAF has already metered that mass of air and now it is not present.
the stock BOV re-circulates AFTER the MAF (and before the turbo). if you vent into the atmosphere, the turbo is still creating suction which instead of air coming from the re-circ hose, it's pulling it from the intake. with more air coming in (through the intake), the MAF see's this and adds fuel. this is how the rich condition occurs.
Quack is offline  
#21 Old 10-13-2004, 07:41 PM
WRXpert
 
dumdum's Avatar
 
Join Date: Sep 2004
Location: Virginia
Posts: 2,800
Images: 12
dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention
Quote:
Originally Posted by Cosmo
In order for that arguement to hold true, engines would have to function differently. What other things happen in order for a BOV to function? You let off the gas, which closes the throttle body. That forces the air out the BOV or bypass valve. That air has already passed by the MAF sensor, however either way it's not going into the engine, so that "extra fuel" is not mixing with any air anyways. If somehow the bypass valve diverted the air into the intake manifold, that arguement would be true. But, since it diverts it back into the intake tube before the turbo (recirculating) that air isn't going into the engine anyways.

And, a BOV is actually better at keeping the turbo spooled. Backpressure that builds up in the intercooler slows the turbo down. That backpressure usually isn't much of a concern because most of it is being drawn into the intake manifold. But, once the throttle body closes, the pressure inside the intercooler raises significantly. That backpressure makes it harder for the compressor wheel of the turbo to spin, thereby slowing it down. The stock bypass valve recirculates it into the front of the turbo again, which helps, but it is harder for the turbo to spin through that already-compressed air. The BOV relieves pressure inside the intake to allow the turbo to spin freely.

Well, that's my take on it anyways....
Your theroy sounds reasonable but also in the book "Maximum Boost" it is stated as i explained it in my former post.And Corky Bell is pretty much high on the turbo food chain.The turbo doesn't have to spin on the compressed air because when the divertor valve opens the pressure drops in the intercooler and there is no load on the turbo durring the shift so the diverted air "pinwheels" the compressor wheel.

Homebrewed tuned with Opensource!
dumdum is offline  
#22 Old 10-13-2004, 10:46 PM
WRXtuners Member
 
Solice's Avatar
 
Join Date: May 2004
Location: Pennsylvania
Posts: 242
Solice is an unknown
Send a message via AIM to Solice Send a message via Yahoo to Solice
Quote:
Originally Posted by rokstar
If you take out your intake silencer, you'll hear your turbo spool up louder, but I never heard the stock BOV until I took out my intake and replaced it with a ram air intake. Now I can really hear the stock BOV from inside AND outside the car.

Rokstar
All I did was take out the silencer and I can hear the stock BOV loud as day. I just wasn't sure If it could be heard outside the car too. Thanks guys
Solice is offline  
#23 Old 10-13-2004, 10:46 PM
WRXtuners Member
 
Join Date: Jan 2004
Location: Illinois
Posts: 18
Boomshine is an unknown
Talking Stock BOV

Dude u guys are wasting ## money on BOV's. If u want that bov sound go with this

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

Get that mount both those horn things on top of ## roof and have fun. roll up to a civic at a lite. Don't REV IT PHSSST IT. dude u'll get chick like a doctor gets pills. and u could show off to ## buddys. all u gotta do is make the PHSSST noise and they know whos boss. when ## at a lite its not about who pulls on who. Its about who can make the most noise, look stupid and lose.


IMO= Get the mods for a car before u get the sound. its just like saying get the power before u get the bodykits.
P.S.
Not trying to be mean just trying to give everyone a luagh. !Laugh! !Laugh!
Boomshine is offline  
#24 Old 10-14-2004, 02:14 AM
WRXtuners Member
 
bah14's Avatar
 
Join Date: Jan 2004
Location: Ohio
Posts: 266
bah14 is an unknown
GEnts,

So say you install an HKS SSQ bov. Will the bov sound be considerably louder once the intake silencer is removed?

"I hear Buschur Racing does WRX UTECs now ... oh buddy!"
bah14 is offline  
#25 Old 10-14-2004, 11:40 AM
 
IBAUCLAPlaya's Avatar
 
Join Date: Oct 2003
Location: Ohio
Posts: 3,488
Images: 8
IBAUCLAPlaya is known to be trustworthy and helpful IBAUCLAPlaya is known to be trustworthy and helpful
Send a message via AIM to IBAUCLAPlaya
That is completely stupid to get on the WRX. That is extremly expensive and it screams ricer. IMO if you want hte BOV sound, get a BOV, no fault in that. Your car IS turbocharged unlike the ricer civics that buy that product. Although it doesn't help performance, I admit it sounds pretty cool and scares the crap outta people. If I ever saw somebody buy that, I would have absolutely no respect for them ever. That is the dumbest invention ever made. But what is funny is, somebody has to buy them since they are being produced.
IBAUCLAPlaya is offline  
#26 Old 10-14-2004, 11:51 AM
WRXtuners Member
 
Cosmo's Avatar
 
Join Date: Dec 2002
Location: Virginia
Posts: 4,591
Images: 15
Cosmo is known to be trustworthy and helpful Cosmo is known to be trustworthy and helpful
Send a message via AIM to Cosmo
Quote:
Originally Posted by bah14
GEnts,

So say you install an HKS SSQ bov. Will the bov sound be considerably louder once the intake silencer is removed?
No. With the intake silencer removed, what you are hearing is the sound of the stock bypass valve recirculating the air back into the intake. With an atmospheric BOV, that isn't occuring, so the only sound you will hear is the BOV itself.
Cosmo is offline  
#27 Old 10-14-2004, 04:02 PM
WRXpert
 
dumdum's Avatar
 
Join Date: Sep 2004
Location: Virginia
Posts: 2,800
Images: 12
dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention
The BOV's are meant for racing applications that are boosting over 25psi where a divertor valve just won't handle expelling the pressure/air fast enought.They are just to small.They do sound cool but just impractical.

Homebrewed tuned with Opensource!
dumdum is offline  
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On