Downside to dual chamber blow-offs ?

[Pezking]

So, I was looking to replace my stock 2g BOV and I was wondering if there was a specific downside to these dual chamber or dual drive blow-offs I've found. I haven't seen many people with them here, so I was thinking that maybe there is some problem with them.

I am thinking about getting a Blitz DD, of course I'll have to come up with something to recirculate it ( don't want to vent ) and have already found a tech article for that.

HKS makes a recirc kit for the SSQV, but I think it doesn't sound good at all, my brother has one on his SR20DET...

The Apexi can't made to be recirculate from the way it looks or am I mistaken there ?

So, any reason not to get a dual drive/chamber/valve BOV ?

// Edit : I'm running stock boost at the moment and am not planning to up it very far, just doing the bcs-mod and some basic bolt-ons.

 

[95blackGsTurbo]

If you don't plan on turning the boost up very far then I would go with a 1g BOV. I have never been impressed with the Blitz BOV. Or any dual-chamber BOV. I would stick with what work's and the fact that it is cheap and easily recirculated. If you aren't going to run more than 15 or 16psi then I wouldn't worry about spending a lot of money on a BOV.

 

[polarmoment]

go for a stock MR2 valve. they cost about the same as a 1g, are easier to plumb in, and not only react faster at any boost level than a 1g, but it is impossible due to their design for them to ever leak, no matter how much boost you throw at it. they actually sound pretty good too if you have an open filter element. let me know if you have any questions about it.

 

[1gfromND]

go for a stock MR2 valve. they cost about the same as a 1g, are easier to plumb in, and not only react faster at any boost level than a 1g, but it is impossible due to their design for them to ever leak, no matter how much boost you throw at it. they actually sound pretty good too if you have an open filter element. let me know if you have any questions about it.

Yeah can we get a pic of this bov I'm curious to see what it looks like especially if it has no downside to it like leaking and such. Sam

 

[polarmoment]

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they're actually black, but i painted mine.

the valve seat is oriented so that boost pressure does not push it open, it pushes it closed. pressure in the lower port partially tries to push the valve open, negating that force vector. pressure in the upper chamber then pushes the valve closed under boost and pulls it open in vacuum, so the valve reacts as fast as pressure falls in the intake manifold. it's almost identical in design to the HSK SSQ just without the dual valve seat.

hook the top port to manifold vacuum and the bottom port to the wastegate boost reference port.

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the smaller pipe off the valve on the flanged side is the inlet. it's too small to clamp into the 2g pipe by itself, but i went to the hardware store and bought a piece of PVC pipe about 1.5" long by 1.25" diameter and sanded the inside down so that it just barely *wouldn't* slip over that pipe. heat it up a little and it'll stretch and slip over it. then i JB welded it and used a 1/4 wide hose clamp to hold it.

it pressure tested (when hot) to 30psi without leaking.

this is what it looks like installed on my MR2:

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