Wrx intercooler plumbing

[xforxlifex]

Plumbing it into an ea82t. I understand about the main plubing (blah blah to throttle ect.) Im a little confused on the plumbing of the blow off valve. The goldish bronzish top part of the bov, that im guessing vents back to the intake manifold? Also the 1 1/2" piece of tubing that comes out the bottom of the bov, what is it for where does it plumb to?

 

mike

[sub87dl]

Mike,

 

Could the mystery hose be the intake manifold vacuum-assist line? I think that the BOV is actuated by two mechanisms that are complementary to each other:

 

1. Sudden transient pressure increase inside manifold plenum (IC outlet) means throttle plate has snapped shut for a gear shift. This causes the BOV to open up and vent boost back to the turbo air inlet...

2. The BOV is held open and assisted by the vacuum INSIDE the intake manifold, created when the throttle plate closes.

 

Anyway, I think that's what your mystery hose is, the intake manifold vacuum-assist line. And I think the other lines does return (vent) boost back into the turbo inlet to recycle it.

 

Luke

[xforxlifex]

Thanks for the reply luke,

 

But where on earth do i plumb this rather large hose to? somewhere to the tubo inlet?

 

mike

[sub87dl]

mike,

you should check on the nasioc forum for these types of questions. there's a lot more familiarity with this part over there. also could try scoobymods or clubwrx.

 

hth,

luke

[Dennis ex24]

hes talking about installing a WRX intercooler on a EA82T, not a WRX.

 

without actually seeing this in person, im pretty sure that hose coming off the BPV (BOV) recycles pressure into the manifold. this is how i have my (volvo) bypass valve hooked up and i have no problems.

[Marnix]

The big hose returns the pressure and air flow back to the intake boot before the turbo. If you bleed it into the engine, you will bypass the throttle body and extract power from the engine when you don't want to.

 

Cheers,

[Dennis ex24]

i believe theres a small vacuum line that comes off of the BPV actuator...this one recycles pressure into the manifold.

 

i have my BPV set up how you mentioned, wheres skip when you need him?

[Subarutex]

the large hose coming off the BOV is the recirculation hose. I have run the wrx intercooler/bov setup in 2 forms.

 

The first, i took the metal elbow off the BOV (for the recirculation hose) and made a plate to put in its place that had a mesh over the big hole. Letting the air vent to atmosphere.

 

I have also plumbed the recirculating line back into the air intake. Directly before it goes into the turbo.

 

I noticed very little difference driving wise between the 2 methods. Idle was a little rougher with it venting to atmosphere... but you get the cooler sound. I'm going to be venting to atmosphere again... once everything gets back together.

 

The small fitting on the top of the BOV is the vaccum reference. Plumb this directly to the vaccum line on the intake. (I tee'd the vac line on the front of the throttle body). From this point, I also plumbed my boost gauge.

 

I hope this helps.

[rallyruss]

I go with marnix here.

 

the drop in idle that you see tex is because you are dumping air that the ecm thinks it burned. confusing the a/f ratio our cars rely rather heavily on the A/F meter for fuel control.

 

I plumed mine back into the intake boot at the place where the little silencer used to stick out.

[Subarutex]

I am fully aware that the lack recirculating the air is what causes the idle to be rough.

 

I might add, that I have now programmed my fuel computer to compensate for the lack of air at idle and to reduce the amount of fuel injected.

 

I know you'll ask... i'll state it again. I run an Apexi SAFC. It has a function on there specially designed to counteract venting to atmosphere. Along with 10 tuning points you can set (by RPM) for it to adjust fuel by. It has been the best $150 I've spent. They retail for about $300, but can be found used on NASIOC quite frequently.