Suby Shopping & Maintenance/Warranty Buying a Subaru? Buying, negotiating, financing, insurance, etc. Maintenance/Warranty topics can be discussed here too.

Should I Put My Stock Blow Off Valve Back On

Thread Tools
 
Search this Thread
 
Old 05-11-2004, 09:44 PM
  #2  
Registered User
 
5spdfrk's Avatar
 
Join Date: Oct 2003
Location: Atlanta
Posts: 115
Car Info: 2002 WRB WRX
There are a lot of people with BOVs, and knowing that I would say that it wont hurt your car. But I would run a 50/50 BOV and not a 100% atmospherical one.
5spdfrk is offline  
Old 05-11-2004, 10:01 PM
  #3  
VIP Member
iTrader: (3)
 
Nick Koan's Avatar
 
Join Date: Feb 2003
Location: The BLC
Posts: 17,466
Car Info: Legacy GT
If you have a 100% atmospherical BOV, it can hurt your engine. I don't know if your blitz one is 100% atmospheric or 50/50, but you should probably go back to stock regardless. A 100% Atmo is dangerous because the ECU thinks there is air presure ready to use from the turbo, but the BOV will just vent it out to atmosphere. This screws up the A/F ratio in the cylinder, making the mixture really rich, which is what can cause the damage (and backfires and whatnot).

It doesn't have to do with the tune of the ECU either, as it has more to do with where all the sensors are located.

Moreso, there is no performance benefit from having a blowoff valve. Unless you really like the 'woosh' sound, I'd suggest taking it back to stock.
Nick Koan is offline  
Old 05-12-2004, 10:28 AM
  #4  
Registered User
 
5spdfrk's Avatar
 
Join Date: Oct 2003
Location: Atlanta
Posts: 115
Car Info: 2002 WRB WRX
Or you could try the worx tuning BOV. It is designed specifically for the WRX and is a great bov. Here are just a few posts on it: http://forums.nasioc.com/forums/sear...der=descending
5spdfrk is offline  
Old 05-12-2004, 06:13 PM
  #6  
Registered User
 
5spdfrk's Avatar
 
Join Date: Oct 2003
Location: Atlanta
Posts: 115
Car Info: 2002 WRB WRX
Yeh, and it is a pull type, instead of a push which makes it not as succeptable to leaks
5spdfrk is offline  
Old 05-13-2004, 01:29 PM
  #7  
VIP Member
iTrader: (3)
 
esracer's Avatar
 
Join Date: Dec 2003
Location: Corpus Christi, Texas
Posts: 1,663
Car Info: 2002 Honda S2000
I wouldn't worry about having a blow off valve on your car bro....
esracer is offline  
Old 05-13-2004, 08:51 PM
  #9  
Registered User
 
5spdfrk's Avatar
 
Join Date: Oct 2003
Location: Atlanta
Posts: 115
Car Info: 2002 WRB WRX
bye
5spdfrk is offline  
Old 05-16-2004, 05:55 PM
  #10  
Registered User
 
AWDrifter21's Avatar
 
Join Date: Sep 2003
Location: NJ
Posts: 330
Car Info: 2004 Subaru WRX
Originally Posted by nKoan
If you have a 100% atmospherical BOV, it can hurt your engine. I don't know if your blitz one is 100% atmospheric or 50/50, but you should probably go back to stock regardless. A 100% Atmo is dangerous because the ECU thinks there is air presure ready to use from the turbo, but the BOV will just vent it out to atmosphere. This screws up the A/F ratio in the cylinder, making the mixture really rich, which is what can cause the damage (and backfires and whatnot).

It doesn't have to do with the tune of the ECU either, as it has more to do with where all the sensors are located.

Moreso, there is no performance benefit from having a blowoff valve. Unless you really like the 'woosh' sound, I'd suggest taking it back to stock.
I am not saying you are wrong or I am right, but
why would the ECU "think" there is air pressure ready to use.....???
Shouldn't the computer READ what the car is doing and not GUESS what it mighrt be doing???? Just my 2 cents....
AWDrifter21 is offline  
Old 05-16-2004, 06:51 PM
  #11  
VIP Member
iTrader: (3)
 
Nick Koan's Avatar
 
Join Date: Feb 2003
Location: The BLC
Posts: 17,466
Car Info: Legacy GT
Simply put, the computer screws up the A/F because the car is tuned for the stock BOV, not an aftermarket one. If you have the stock BOV on, the car does know exactly (no guessing involved) how much air is in the system, but an aftermarket one screws with the sensors that tell the ECU whats going on. Someone who knows more about the ECU sensors will have to chime in, as I don't know preciesly where the aftermarket BOV screws you system up.

Bascially:
100% atmo is bad. Makes your car run too rich.
50/50 is better. You get the cool 'whoosh' sound, and the car doesn't run rich (although it gives you no extra performance).
Stock still is the best, but no cool 'woosh' sound.

Last edited by Nick Koan; 05-16-2004 at 09:19 PM.
Nick Koan is offline  
Old 05-16-2004, 08:30 PM
  #12  
Registered User
 
5spdfrk's Avatar
 
Join Date: Oct 2003
Location: Atlanta
Posts: 115
Car Info: 2002 WRB WRX
Why would a 50/50 run rich at idle?
5spdfrk is offline  
Old 05-16-2004, 09:20 PM
  #13  
VIP Member
iTrader: (3)
 
Nick Koan's Avatar
 
Join Date: Feb 2003
Location: The BLC
Posts: 17,466
Car Info: Legacy GT
You know what? I think you are right.

It doesn't run rich, just doesn't do anything to increase performance.
Nick Koan is offline  
Old 05-16-2004, 09:26 PM
  #14  
Registered User
 
5spdfrk's Avatar
 
Join Date: Oct 2003
Location: Atlanta
Posts: 115
Car Info: 2002 WRB WRX
No performance gains, but still teh 'woosh'!
5spdfrk is offline  
Old 05-17-2004, 05:11 PM
  #15  
Registered User
 
iMa5EXYInDo's Avatar
 
Join Date: Apr 2004
Posts: 26
does anyone know if the greddy type S bov is 50/50? I know there is a way to reroute to the intake..but still not quite sure if its a 50/50. Thx
iMa5EXYInDo is offline  


Quick Reply: Should I Put My Stock Blow Off Valve Back On



All times are GMT -7. The time now is 02:49 PM.