BOV question
Hey! Look At Me!! I'm a Supporting Member!!
iTrader: (3)
Joined: Aug 2002
Posts: 4,255
Likes: 0
From: NJ
Rep Power: 0 
Re: BOV question
Originally posted by HondaCivicJosh
when adjusting the screw on top of the BOV what exactly is being done? thanks
when adjusting the screw on top of the BOV what exactly is being done? thanks
The spring keeps the BOV shut at vacuum, so the pressure from the spring needs to be about the same as the boost pressure (but positive). When you're in boost, it helps along with the positive manifold pressure to keep the BOV closed so it doesn't leak. And when you take your foot off the gas, vaccum is applied, and the boost in the piping overcomes the spring with the help of the vaccuum and opens. Hence the reason too tight of a spring causes compressor surge because there is higher pressure in the BOV then the piping, and no way regulate between (equilibrium).
Bottom line: The screw is for softer or firmer spring rates.
Joined: Sep 2002
Posts: 3,857
Likes: 0
From: Arizona
Rep Power: 327 
It helps response a lil bit too. I got a better response with the bov when I set it much stiffer. With a soft setting mine did nothing but flutter like crazy. I still get the flutter now but it's faster and more efficient. Depends on the turbo size. My T04b flutters like hell, but at the same settings, my T3 let it all out in one big guuush. It's mainly due to the momentum of the turbine continuing to spin thus pushin more air than the bov can dish out in one long surge, so it flaps back an forth. It's kinda cool actually. I think I should rig up an audio clip some time to show you guys lol...
Hey! Look At Me!! I'm a Supporting Member!!
iTrader: (3)
Joined: Aug 2002
Posts: 4,255
Likes: 0
From: NJ
Rep Power: 0 Originally posted by RiceRocketeer
OH OH, audio clips of blow off valves would be good.. get them soon!
OH OH, audio clips of blow off valves would be good.. get them soon!
BOOST JUNKY
iTrader: (6)
Joined: Nov 2001
Posts: 1,759
Likes: 0
From: Wide Open Throttle
Rep Power: 0 Just remember that tightening the spring too much will cause compressor surge (as Boosted2k2 mentioned) and that compressor surge is not good for your turbo. It's like putting a brake on the compressor wheel when it should be continuing to spin.
Personally, from what I understand as cool as atmospheric BOV's sound, recirculating them is a more efficient way of using them. Recirculating meaning the air (instead of being released into the atmosphere) is routed back to the intake avoiding running to rich (i.e. too much fuel into the cylinders).
BTW....if when adjusting the spring on the BOV your car seems to bog or stutter, then you've set the spring too "soft".
Personally, from what I understand as cool as atmospheric BOV's sound, recirculating them is a more efficient way of using them. Recirculating meaning the air (instead of being released into the atmosphere) is routed back to the intake avoiding running to rich (i.e. too much fuel into the cylinders).
BTW....if when adjusting the spring on the BOV your car seems to bog or stutter, then you've set the spring too "soft".
Joined: Oct 2001
Posts: 560
Likes: 0
From: OKC, Oklahoma, US
Rep Power: 0 
Originally posted by SpdRcrChk
Personally, from what I understand as cool as atmospheric BOV's sound, recirculating them is a more efficient way of using them. Recirculating meaning the air (instead of being released into the atmosphere) is routed back to the intake avoiding running to rich (i.e. too much fuel into the cylinders).
Personally, from what I understand as cool as atmospheric BOV's sound, recirculating them is a more efficient way of using them. Recirculating meaning the air (instead of being released into the atmosphere) is routed back to the intake avoiding running to rich (i.e. too much fuel into the cylinders).
Joined: Sep 2002
Posts: 3,857
Likes: 0
From: Arizona
Rep Power: 327 Originally posted by RiceBurnrEX
This is true on cars that have mass air flow sensors that are placed before the blow off valve in the intake tract, but since we have a manifold air pressure sensor mounted in the manifold, which is after the blow off valve, we don't have to worry about this. The air will be vented from the intake piping before the MAP sensor sees the air, it will only see the remaining, unpressurized air and provide the correct amount of fuel.
This is true on cars that have mass air flow sensors that are placed before the blow off valve in the intake tract, but since we have a manifold air pressure sensor mounted in the manifold, which is after the blow off valve, we don't have to worry about this. The air will be vented from the intake piping before the MAP sensor sees the air, it will only see the remaining, unpressurized air and provide the correct amount of fuel.
Yeah MAP is all good with Amospheric BOVs. The SSQBOV on my friends MAF GSX sucks though lol... runs mad rich
Thread
Thread Starter
Honda Civic Forum
Replies
Last Post
robjcivic
Mechanical Problems/Vehicle Issues and Fix-it Forum
3
Mar 12, 2017 12:10 PM
JMKendrick
Mechanical Problems/Vehicle Issues and Fix-it Forum
4
Sep 16, 2015 06:17 PM
Bricoleur
I.C.E. (Audio) & Electrical Upgrades
4
Sep 9, 2015 12:23 PM
