Installing a BOV - Some Questions

[ASH STEEVO]

HAs any bought a GFB bov? and whatd ya think??
im lookin at the RESPONS one... so its adjustable VTA or Recirc. reakn this is a avenue for problems??

 

[fieldy107]

Can't see how it would give you problems, from what I have seen GFB stuff looks well built and I'm sure they would have some kind of garauntee against it leaking or anything. As long as you stay away from cheap Chinese knock offs, most bovs shouldnt give you problems. That being said, our cars seem to prefer recirc.

 

[godzilla]

HAs any bought a GFB bov? and whatd ya think??
im lookin at the RESPONS one... so its adjustable VTA or Recirc. reakn this is a avenue for problems??

I have one and it works perfectly. Yes, it is both. Also the spring pressure is adjustable. I cannot see it ever being a problem.

I have it on full recirc though and you can still hear it a little. Sounds cool.

 

[Nitephyre]

Yes, yes they do. Mine got rather cranky with a VTA on.

 

[ASH STEEVO]

yes the do? as in have problems?? i just bought the GFB respons... keen

 

[godzilla]

Not all do Matteh.

When i had my GFB on VTA i didn't have a problem at all.

 

[naughtika]

what is GFB respons?

 

[Black_Ice]

I have GFB stealth on VTA and I have no issues whatsoever...

 

[ASH STEEVO]

cheers dude... youve just reassured my purchase... GFB Respons is suppose to be their best model. so meh, did want the electric controller... and GFB stealth??... not as if we needa go to stealth being the unit is hidden in the engine bay.

 

[Nitephyre]

Not all do Matteh.
When i had my GFB on VTA i didn't have a problem at all.

Ah well, you know my car is strange.

 

[mbilal]

The reason for having a dual port BOV (50/50 vent) is for the noise pollution lovers like me who wants their car to stand out as they change gears. recirc BOV's vent the air back into the intake, as it should be but dont have anything to show off to. VTA (vent to air) units, dump all the pressurised air outside and they achieve that uneek sound (and get the attention of the blue boys if they are around and make room for a yellow sticker for being defective.)
The 50/50 units are for the people that want the sound and yet still make the car driveable.
Reason being is when all the air is dumped from circulation, and you change to a higher gear, the turbo(s) has to compress the same amount of air to the intake, otherwise, there is not much pressure, the timing, ignition, etc. have all been altered with boost and then there is not much pressured air as it has all been dumped out of the system. This in turn makes the car jerk after gear change until the desired boost is achieved again and can cause detonation and other damages.
with these ones, you dont have too much noise and still provide air back into the system.
nuff said, now I just have to figure out how the cars with VTA BOVs are configured without any jerking or loss of power ( like the way my car is setup at the moment).
When I haid a 6G Galant, and my first turbo car, I used to take the recirc pipe out to vent the air out and achieve the BOV sound, pretty dumb thing to do, but I was experimenting...
After full rebuild, (yes I killed my engine, it was half dead anyway) Bought a turbosmart dual port.
Lovely things, these BOVs, until you get caught...

 

[godzilla]

Bilal, good write up but you have just a couple of things not exactly correct.

A) just for a start, VTA stands for 'Vent To Atmosphere'
B) the reason why MAF equipped cars sometimes have issues with VTA BOV's is because when you dump a metered amount of air, without it being burnt, the Oxygen sensors fooled by there being a heap of air missing and dumps fuel. This richens the mixture up and causes it to run rough.
C) See, the recirc feature retains the air that the BOV dumps in the system so none is lost. This equals happy O2 sensor.
D) just lastly, the idea of the BOV was always to protect the turbo against compressor surge by releasing the air so it doesn't bounce back off the closed throttle butterfly. The actual compressor wheel keeps spinning in-between gear changes so it has momentum when trying to build boost in the intake system again.

 

[ASH STEEVO]

POW... right in the kisser... cheers trev, you just up'd my knowledge, cheers

 

[Jimmy_EC5W]

Just realized my question on the first page was never answered!

Here's again. Will any BOV fit without some sort of adapter kit or do I need something for it to fit?

And no I dont want an evo 8 metal bov. My mate has an evo 5 with a blitz bov and seems to work well, and, in saying that, their is one on firesport that was "off a 180sx".

 

[unclepaulie]

You will need an adapter of some sort ifthe bov in question isn't to suit a hose with an internal diameter of 34mm

 

[VOLK]

Little OT but Trev's post got me thinking. My understanding was MAF equipped cars overfuelling with VTA BOV was nothing to do with O2 sensor and purely an operation of ECU seeing voltage from MAF and fuelling accordingly. O2 sensor are generally for closed loop refinements of A/F at cruise/idle. That's my understanding anyway. Thoughts? Any mechs wanna chime in?

 

[sn00ze]

I think your correct in that when the system is in open loop which is alot of the time the ecu isn't even looking at the o2 sensor. I'd tend to think it has more to do with the maf voltage too, alot of our cars are old enough to have lazy o2 sensors by now if not replaced, if they're pegged on rich already and it's lazy or not moving it's voltage at all, then there's no more room for scope with a vta to adjust fuel anyway. The o2 sensor is measuring oxygen in the exhaust anyway, it doesn't care about anything upstream of the dump pipe, as long as it sees the amount of oxygen it likes in the exhaust, then it will tell the ecu it's all sweet

 

[unclepaulie]

The Maf adjusts the fuel thinking the air from the bov will be recirced so the amount of fuel is to suit air being intaked + the wasted air, so when it's wasted the air/fuel ratio is now rich as there is less air in the system.

 

[Guest]

Who needs a blow off valve, just change gears next to a bus at the right time

 

[VOLK]

So the general consensus is I'm correct. I win at keyboard mechanic