Stock ByPass Valve on 1JZ question

[Datsrboi]

I know the stock bypass valve has two nipples on it (One on the top and the other one below it).

I was looking at some pictures and notice on everyones car that they have a little valve on the top nipple. Mine just has a hose coming from the manifold and T'd off to both nipple with no little valve thing on the top one..

Do I need that? Is it a one way valve? If so what way does it have to go? Would suck if it will not open up to relieve boost when i drive it later today.

 

[10secdream]

I think the little valve you are referring to is a filter. I don't have one on my car and it works perfectly fine.

 

[annoyingrob]

No, it's actually supposed to be a one way valve.

IIRC, it allows the valve to hold pressure under the diaphragm when you let off, to open it faster.

 

[Datsrboi]

No, it's actually supposed to be a one way valve.

IIRC, it allows the valve to hold pressure under the diaphragm when you let off, to open it faster.

Without it the bypass valve will not work right? Its suppose to suck the air out of the top one not the other way right?

 

[apexi287]

I have a feeling it will make it fail sooner. I don't have one on mine because the plastic nipples on the valves broke, so I just replaced it with just a single vac line.

 

[annoyingrob]

Without it the bypass valve will not work right? Its suppose to suck the air out of the top one not the other way right?

It won't hurt it without it, it'll work fine. It MIGHT surge, but it's unlikely.

I'm going purely from what I would imagine to be correct, as I can't remember how mine was set up, but I would assume the bottom one has a one way valve letting pressure in to it, but not out, and the top one is just connected normally. That way, under boost, there's pressure on both sides, and the spring tension keeps it closed. Then under vacuum, you have positive pressure underneath, and vacuum on top, allowing it to open faster. I would assume there's a small relief inside the valve to bleed the pressure underneath off slowly (much like an SSQV).