legacycentral bbs

So a friend of mine took one hose off of his BOV, and it made it incredibly loud.

Does anyone know what this hose was and where it is located?

Ya, the hose he took off is the hose that comes from the outlet side of the bypass valve(bov), and goes to the intake pipe.

as long as you plug the hole on Boot B (90 degree rubber turndown for turbo inlet, with PCV fittings on it) where the blowoff valve recirculates into, that hose can be left off for a Darth Vader-type exhale sound upon shifts. Not sure how much boost our stock valves can hold before they start to leak, and without the recirculation hose on there the leak will be external to the system instead of re-entering it before the turbo.

I ran like that for quite a while before I got the FMIC in and could use a real atmospheric BOV again...

So this will not hurt the car or take away any performance?
Does anyone have a pic of this assembly?

Actually, it will drop your performance slightly; between shifts, your turbo will spool down quite fast without a recirculating BOV.

Where the air re-enters the intake system, it also keeps the turbo spinning - so when you engage the next gear it will take slightly longer to spool the turbo back up if you are running atmospheric.

and your idle will be shit.

Yea, my car didn't idle after I revved it.

Works perfectly with an actual atmospheric BOV.

I'm going back to recirc I think. Just better for everything, and I have given ample time for people to hear that my car is faster than theirs.

As long as I can hear a slight "pssh" I'll be happy.

right, forgot about the idle part - its been so long since I've had idle problems

Yeah I tryed this morning and had the same problem. Just really poor performance.

would it be alright to stick an aftermarket BOV on there with my stock turbo, stock engine completely right now since i just dropped it in ?
Turbo xs I hear makes a nice atmospheric
Exactly BAC5.2, I just want people to hear it haha

The only atmospheric BOV I can recommend from my experiences is the HKS SSQV. Put aside the incredibly loud whistle resulting from blowing off even 1 psi of boost...but those 3-chamber valves are designed in such a way that they are guaranteed to not leak at idle, or at any boost level below like 50 psi or so. Which is a nice limit to keep in the back of my head

The GReddy Type S sounded cool, but I think we've determined they leak at anything near or above 17 psi. Not good. They also seem to confuse our cars' idle, although the ECU does learn around this so the idle situation is eventually a non-issue (same with the stock BOV run as atmospheric - give the ECU time to adjust around the idle leak)

With the SSQV.. its actually tough to KEEP people from hearing when your car vents pressure. It'd be nice if I could remove and reattach the whistle portion of the valve, just letting it pssh instead. But hey, if I've got a leak somewhere at some point, I KNOW its not the blowoff valve....which I couldn't have said about my previous setups...

OK I tried pulling off the hose, and after revving it, like you said, the idle was shit. How can I fix this idling problem, as I really enjoyed the sound of the atmospheric setup?

time. Just time. Your ECU must learn to compensate for the temporary leak that is created after the BOV is open. I'd say after a few days of driving it like that it should all but go away.

I don't think we have an idle adjustment screw, but if you adjust your idle up slightly it might help your ECU to learn around the leak...

OK so this is nto doing any damage to my car, and I just have to keep the revs up for a few days?

Thanks for all the help, it is greatly appreciated.
-Brad

free5ty1e wrote:time. Just time. Your ECU must learn to compensate for the temporary leak that is created after the BOV is open. I'd say after a few days of driving it like that it should all but go away.

I don't think we have an idle adjustment screw, but if you adjust your idle up slightly it might help your ECU to learn around the leak...

We do have an idle adjustment screw, but you shouldn't mess with it. The ECU controls idle and messing with the screw just confuses it.

good to know, as soon as I fix my oil leak I will be running atmospheric

fun, aint it?

errr, not as much fun as I thought.
Is it possible to do permanent engine damage this way? I had everything set up and my idle was shit for 3 days so I connected everything back to stock. My idle is still shit...

huh, mine adjusted within a week or so IIRC, when I had the stock BOV open like that.

I don't believe that could cause engine damage, its just trying to stall out when the valve stays open after the pressure's been vented and becomes a post-MAF vaccuum leak.

anyway, a real atmospheric BOV is much better at closing after the pressure's been vented.

Did you reset your ECU each time you switched? That gives it a much better start from which to learn. The fact that your idle remained shit after you switched back to recirc means that it was learning around the leak...

You need a aftermarket valve. The stocker is open at idle, thats why the idle is crap with the hose off the valve.

Ah, this is why I come to you guys for the wisdom that I myself do not posess just yet
I did not reset each time i switched, and that makes a lot of sense actually.
Thank you, and you say you drove with the stalling for about a week? I don't know if I can handle that.

Yeah, lol, I'm a stubborn mofuggah... I had just removed my Saab TMIC and GReddy Type S blowoff valve in favor of the stock setup (as it resulted in lower 1/4 mile times) and couldn't deal with how silent the damn stock valve is without the hose off.

If you're as determined as I was to drive like that, you'll have to keep showing the car every time it wants to stall that all it has to do is open the throttle up a little. It'll learn.

Ah, the fun and interesting things you can do with a Legacy Turbo

Unfortunately, this isn't one of their free articles (so you need to have purchased issue #57 to read it), but this AutoSpeed article describes a great method for venting factory bypass valves without venting air at idle (it's essentially a form of bleed like you'd see in bleed-style boost controllers).

http://www.autospeed.com/cms/A_0344/article.html

Unfortunately, last night I had the worst night of my life, and none of this is any longer my main concern. I wrote my car off last night, and I am left with a hole in my life lol.
God dammit, this car has honestly been nothing but trouble for me, and maybe it is a good thing this happened.

Which hose is this I'll give it a try.. I dont even know where the BOV is.?