legacycentral bbs

most if not all BOV's (loud ones) have adjustment screws on them that allow you to adjust the tension of the spring depending on your car.

personally i'm not sure if i completely understand either. a re-circ BOV, recirculates the air, and puts it back into the intake track, right before the turbo. Yet an atmospheric BOV vents the air to the atmosphere, yet when you step on the gas again you are still sucking in lots of air from the filter. So what causes the lagging?? If it's just a little bit of a rich condition and backfiring...that's cool, cause it makes it sound even more like a rally car.

Austin wrote:The ill effect of removing your bypass valve is that without one, when the throttle plate snaps shut, it sends a huge reverse wave of pressure against the compressor blade. Not only will that slow the shaft down quite a bit, but if it's bad enough you can snap compressor blades.

Thats not really much of a problem on an automatic, I can pretty much control if I want to "slam the trottle plate shut." As far as the compressor blade thing, you're probably right, but as of yet nothing has happened, and I've slammed it shut at 16psi+ before....

Get a partial vent to atmosphere one.......that way you're not totally freakin the computer out....but are getting some noise.

Personally.....if you want a BOV for noise only......you don't need one.

Josh: which valve would be best to get from a performance standpoint with the noise aswell, feel free to list others then what i've linked to here. You mentioned partial vent to atmosphere, can you point me in the direction of who makes them and where to get them?

Would this be the GFB stealth one that I posted on P1 of this topic?? It's user specified how much gets recirculated and how much goes to atmosphere, so that would allow me to tune it for the best performance and noise, right?

Aaron: With regards to when you say a lag after the shift, would the be conisdered slower then the stock BOV, or the same... I guess this is the determining factor, if the loud one performs the same as stock but not quite as well as the quiet one I don't care. However, if it's worse then stock why then bother??

Again, I apologise for my lack of knowlege in this area. (I think I may be done after this post )

inzomniac wrote:With regards to when you say a lag after the shift, would the be conisdered slower then the stock BOV, or the same... I guess this is the determining factor, if the loud one performs the same as stock but not quite as well as the quiet one I don't care. However, if it's worse then stock why then bother??

I think you're finally getting it. An aftermarket ATMOSPHERIC BOV will perform crappy compared to stock. An aftermarket RECIRCULATION valve will work exactly like stock.

You only need an aftermarket BOV when going above 18/19psi, maybe more (I say going over this mark because I've tested the stock BOV to this point). Once you go over this point, you'd better have engine management to go along with that boost anyways, so all of the issues we're telling you about won't apply.

I say save your money for something that actually makes your car faster, but if you really want the noise, be my guest.

BTW, Josh is probably talking about the GFB BOV.

I really wasn't specifically talking about one particular valve or not......I'm not familiar with all the ones out there.

As Jason said, you really don't need a different one from a performance standpoint until you go to higher boost.

If you were to run the BOV to atmosphere you will get a decrease in performance. If you have an ECU that you can program to compensate for the venting to atmosphere you'd probably be alright....or better.

The reason you have a bogging after letting off the throttle and the metered air venting to atmosphere is because you have an extreme rich situation because there is less air then the computer thinks.

A larger BOV will work better than a small one especially at high boost this is because that being larger it can handle more air in a given time. The forge valve also has different springs available for it. Mine is a earlier model with a plastic piston that is sticking and they are replacing it. If you want a Forge valve you may want to try larry@subaruplanet.com he knows about these things and is helpful this is where my valve came from.
AL(CO)
al@iwtu.net

ok.. as far as I'm concerned the problem is solved...

I'm not going to bother, I mean as good as it sounds I'm not about to ruin my cars performance for the sake of a phhtsss when I shift. Thanks for the information so I didn't waste my money on a BOV I don't really need, and would have been detremental to my performance

Thanks for the patience!!

This means I have to face the fact that I need to start putting money away for my inevitable rebuild (valve seals are going, only leaking on ilde now, but give it time )

If you want a temporary noise, just disconnect the hose going from the bypass valve to the intake tube, and when you get sick of it, just put it back on. It gets pretty loud, especially over 10psi....

Hehe. This I've gotta try sometime . . . just for the helluvit

haha!! I'll givver a go