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I could put a hand on a Cheap HKS SSQ Bov ...

think that would be a good move ?

considering intercooler in the way + some tuning ... ?

I already put the HKS BOV on my 92 Legacy turbo , it sounds sweet!

Ben

I finally chocked... that money will be at better use on a new set of brakes

The stock WRX intercooler has a BOV right? Has anybody heard it? How loud is it?

Thanks,
Mark

the stock WRX BOV is a recirc valve like ours IIRC, and is just about as loud.

Can the stock recirc valve be vented to atmosphere for more sound? Will doing this hamper the way the engine runs?

Thanks,
Mark

it'll sound kinda funny. it has a cool flutter noise, not the disney animatronics pneumatic "psshhhhh" that atmospheric BOVs have.

It will leak at idle and cause the car to run rough or not at all. It does sound kinda cool though.

It will leak at idle and cause the car to run rough or not at all. It does sound kinda cool though.

If I route it to vent to atmosphere? I noticed under boost and high rpm shifts even the stock recirc valve makes a pshhhh sound, but it is soo quiet

Mark,

Just try it out once!

Pop off the hose that recirculates back to the intake elbow, and plug the hole at the intake so you don't suck in unfiltered air.

It's actually pretty damn loud under high boost, but you'll run REALLY rich and get about 12 mpg, so I wouldn't do it permanently.

But it's worth it to hear it for a trip around the block.

-mike

Yup, sounds cool but....

...Exactly, sounds bad-@$$, but runs like crap. Just eliminate the MAF and convert to a MAP, and you won't need to re-circ.

Most of the problem is that the stock valve leaks at idle. An aftermarket valve that is made as a blow off type should work ok, it'll just run rich during a shift, and you could argue that it's good to do that.

That's assuming that you're pushing boost at all times, which most likely, in daily driving, you're not. Anytime the BOV senses vacuum, it's open, and that's when it's leaking, as well as at idle.

If you run mostly WOT, then yeah, you'd only leak during shifts.

-mike

I did this today. Pulled the recir-valve off the nipple on the intake plumbing. WOW, that sounds really, really good. I didn't feel any difference in performance though??? But you guys say it is detrimental to performance, will driving like this hurt anything? Could it be possible to keep the sound and make it run at its best (without buying an actual BOW)?

Thanks,
Mark

Yeah, you're gonna be running real real rich, and thats never real good for the plugs, injectiors, or your cat. Smell the exhaust (or watch it billow out of the tailpipe) and you'll know something's up.

As for the sound, place a small microphone inside the re-circ hose, and hook it up to the AUX IN of your stereo head unit. You'd even have volume control over your blow-off, not to mention the EQ and DSP possibilities! A little reverb might just be what the BOV sound needed.

ROFL...

I couldn't see any black smoke out of the exhaust. Does this car rely so much on the MAF? Wouldn't the O2 sensor sense the rich mixture and so the ECU would compensate? When the recirc-valves are vented to atmosphere will it only momentarily run rich during a shift or when easing up on the throttle? Or will it run rich all the time? The difference (between venting to intake and atmosphere) I noticed, was a small loping idle when the engine was cold, thats about it. I don't mean to be skepticle about your knowlege, I'm just curious how I could make this work.

Mark,

Interesting article on how to convert a Recirc. Valve to Atmo. BOV.

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

This car/engine is EXTREMELY dependant on the MAF.....it'll run all day with a disconnected O2 sensor.....it may not run too well...but it will run.

Well that looks like it would work, I just might find out...

Well I tryed doing what the article said and........... It worked so far, my idle is just right and you can hear the BOV. I am going to see if I can adjust it to see if it get's lowder with out hurting the Idle. All in all the cost of it was not too much but compared to an aftermarket BOV it is much, much cheeper........ If you all want I can post some pics but I will need someone to host.

The only real BOV that really work on our Legacys is the one made by APS
http://www.airpowersystems.com.au/

It's a standard recirculating and an atmospheric blow off valve.
It's really exppensive but it's the only really working thing...

How is it both a standard recirculating valve and an atmospheric valve? What's special about APS' BOV that would make it not upset a MAF-based fueling system?

My brother wants me to make a circuit with a loudspeaker under the trunk that reads off the manifold pressure sensor and makes a loud "Pssshhht" sound whenever the pressure drops rapidly from more than 5psi to less than -5psi.

Think there's a market for "electronic blowoff valves?" :)

Hey GizMo22t,

Could you do me a favor and watch your gas milage for a tank or two and get back to us? It seems to me that, where the Autospeed rig would have less effect of bleed-off during idle, any "pssssht" that you hear is still MAF-measured air not being used by the engine, but all along being compensated for by fuel. I really want to do this, but I can't logically figure out how this would work.

Thanks,
-mike