This is a quick of list of answers to FAQ's regarding BOV's in an attempt to prevent any new members from making the mistake of making a thread asking one of the most taboo of questions.
-1- Can I just remove the tube that connects the bov to the intake pipe and plug off the hole on the pipe to make it sound louder?
Simple answer is NO! (please read on for explanation)
-2- Why does my car stall or have really low rpm's when shifting into neutral, or coming to a stop when venting my bov?
Air is metered by the maf, this tells the engine how much air is coming in. When you vent, you vent air that has already been metered, this is air that your engine in expecting to use. By venting you are throwing off the tune of your engine.
-3- My car doesn't stall and runs fine when I vent, I like the sound so whats the big deal?
Not every car will demonstrate the usual side effects of venting a bov incorrectly, but that doesn't mean that it is healthy for your engine. (please read #4)
-4- What harm can becaused by venting incorrectly?
Vented air leaves through the bov when you shift or let off the throttle, that air is accounted for by the ecu so it still adds the fuel for that amount of air. Since the balance is now incorrect it runs rich which can cause problems such as oil wash (leading to thinned oil and spun bearings), fouled plugs, carbon buildup, backfires, stuttering, stalling at idle, if the bov is open at idle (like many are) it can cause lean idle and suck in dirty/unfiltered air. It should also benoted that your car will be running richer and your gas milage will suffer greatly costing you more $ on top of the possible damage to your engine.
-5- What do I need to vent my bov correctly?
There are plenty of methods that allow you to do so in a manner that is safe for your engine. Some of these methods include the following setups:
-MAF-t setup
-AEM EMS
-VCC
-Haltech
-Megasquirt
These are all quite expensive just to attain a louder whoosh sound, and on a side note it is important to understand that with all of these setups, venting is only a "bonus" to all the tuning power they provide, which should be your primary goal.
-6- I have an s-afc so can't I just use that to compensate for venting?
No! Please read #5
-7- I just spent alot of $ and bought a new upgraded bov that doesn't allow me to recirculate. What can I do?
You may have to search around a little but most performance bovs (with the exception of some such as Tial's) offer kits that allow you to recirculate. A few of the more popular brands that offer such kits include Greddy, Blitz, and Synapse. So please do yourself a favor and find a kit that corresponds to your bov.
This was a quick thread created to answer a few of the FAQ's regarding venting your bov. I do not take credit for most of the information since it was created by compiling information posted by various veteran members of this site. However, I figured that it would be a useful thread for those considering venting their bov. I hope this answers any basic questions for those who actually search and to the mods please feel free to correct/add any information that they feel appropriate
-1- Can I just remove the tube that connects the bov to the intake pipe and plug off the hole on the pipe to make it sound louder?
Simple answer is NO! (please read on for explanation)
-2- Why does my car stall or have really low rpm's when shifting into neutral, or coming to a stop when venting my bov?
Air is metered by the maf, this tells the engine how much air is coming in. When you vent, you vent air that has already been metered, this is air that your engine in expecting to use. By venting you are throwing off the tune of your engine.
-3- My car doesn't stall and runs fine when I vent, I like the sound so whats the big deal?
Not every car will demonstrate the usual side effects of venting a bov incorrectly, but that doesn't mean that it is healthy for your engine. (please read #4)
-4- What harm can becaused by venting incorrectly?
Vented air leaves through the bov when you shift or let off the throttle, that air is accounted for by the ecu so it still adds the fuel for that amount of air. Since the balance is now incorrect it runs rich which can cause problems such as oil wash (leading to thinned oil and spun bearings), fouled plugs, carbon buildup, backfires, stuttering, stalling at idle, if the bov is open at idle (like many are) it can cause lean idle and suck in dirty/unfiltered air. It should also benoted that your car will be running richer and your gas milage will suffer greatly costing you more $ on top of the possible damage to your engine.
-5- What do I need to vent my bov correctly?
There are plenty of methods that allow you to do so in a manner that is safe for your engine. Some of these methods include the following setups:
-MAF-t setup
-AEM EMS
-VCC
-Haltech
-Megasquirt
These are all quite expensive just to attain a louder whoosh sound, and on a side note it is important to understand that with all of these setups, venting is only a "bonus" to all the tuning power they provide, which should be your primary goal.
-6- I have an s-afc so can't I just use that to compensate for venting?
No! Please read #5
-7- I just spent alot of $ and bought a new upgraded bov that doesn't allow me to recirculate. What can I do?
You may have to search around a little but most performance bovs (with the exception of some such as Tial's) offer kits that allow you to recirculate. A few of the more popular brands that offer such kits include Greddy, Blitz, and Synapse. So please do yourself a favor and find a kit that corresponds to your bov.
This was a quick thread created to answer a few of the FAQ's regarding venting your bov. I do not take credit for most of the information since it was created by compiling information posted by various veteran members of this site. However, I figured that it would be a useful thread for those considering venting their bov. I hope this answers any basic questions for those who actually search and to the mods please feel free to correct/add any information that they feel appropriate
