BOV? Newbie Q...

[spitfiresk0690]

As it says in the FAQ's:

"In order to make a BOV loud, you have to vent to the atmosphere (as opposed to back into the intake, like our cars do from the factory), releasing the excess air instead of routing it back into your turbo system. The problem with this, is that your ECU has already accounted for this "excess air" and adjusts fuel curves accordingly. If it's not in the system anymore, the ECU is compensating incorrectly. This means that the car will not run the way it's supposed to. It may idle poorly, or it may not be noticable - but it will have a negative effect, even if you can't feel it (the logger will prove it). In any event, it is not the best thing to do if you are serious about making maximum performance."

I'm sure this has been answered many times, and ive done searches and looking in the FAQ's but, how do you disconnect the tube that runs the BOV into the atmosphere with out having the car run differently cuz of the ECU?

 

[Generation1JeY]

alright let me tell u something that most of the tuners on this website won't just because they hate having anything to do with riceness.

The ONLY performance change u will notice with a vented bov is the fact that it leaks. With a leaky bov at idle, it will cause u to bog, buck, give u terrible pulsing idle, and it wil make u stall when u let off the gas quick. The stock 1g bov WILL leak at idle if u vent it, hence giving u a vacuum leak making ur idle screw up, and cause u to have the problems above. Now normally when the 1g bov is recirculated it does leak at idle, but when it leaks it retracts the air back into the intake making the engine not lose any air out of the system, so u have a steady idle and everything works.

Having that be said there is only one thing u want to make sure happens when u vent a bov, MAKE SURE IT DOES NOT LEAK. By crushing a 1g bov or modifying it in another way so it doesnt leak at idle will work, as long as it doesnt leak at idle u will be fine, but honestly the 1g bov doesnt sound very good vented. If ur really interested in having a good bov sound that u can vent correctly, is to buy an aftermarket blow off valve, aftermarket bovs will not leak at idle and are fully adjustable, so the only problem u will have will be the rich conditions when u drive.

The TRUE way to vent correctly is to get a blow thru maf, anything like a gm maf sensor placed AFTER the bov so that the air that leaves the bov is still accounted for since the sensor is after it. Or other stand alone systems like the hks vpc. But of course getting tuning compatible sensors are not very cheap, and there is work involved, so if u really want to vent for whatever reason, just make sure that the bov does not leak at idle, if ur idle is fine then ur car will have no side effects of venting except for the rich shifting.

 

[spitfiresk0690]

But if your venting it, doesnt the ECU still think that the air that is now going into the atmosphere is still going back into the intake? I dont understand.... If i got a aftermarket BOV, does it still utilize that tube that puts the air back into the intake?

 

[WI_99'GST]

yes many of them (greddy type s, ssqv, and other popular ones) WILL allow you to recirculate. With the greddy you can just recirc it, but with the ssqv you need to buy ATLEAST the recirculation fitting. YOu can also buy a recirculation kit for the ssqv, but it really isnt necessary.

 

[Generation1JeY]

if u vent without a blowthru system, u will have rich shifting, period.

But its not the biggest deal in the world, if ur the kind of person that likes aggressive bovs, then go for it and dont let some performance junkies tell u otherwise. I vent my rfl bov with no blowthru system and my car feels the exact same way it did with my old 1g recirc bov, so the choice is urs.

 

[Defiant]

That was five posts longer than it needed to be.

Please check the FAQ about venting.