Black Lunch Box Behind MAF - what is it?

[Nutter128]

:blush: This is Probably a bit of a no-brainer for most of you chaps, but I'm not called "nutter" for Nothin' :2ponder:

I recently changed the old air box on My Wagon for a HKS induction doofa. but before doing so I had a peek at Stevie12's setup (just to be sure it was as simple as it sounded).

I noticed that just behind the MAF sensor I've got a large plastic "Lunch-Box" fitted, Where Steve's didn't. On first glance it looks like a fancy way to connect the Breather to the air intake, But I then noticed that there is another pipe that connects it to a couple of valve-relay-pump-looking thingys attached to the OS wing.

What is it? What does it do ? what's the other pipe for? Can I get rid of it without killing Scoob? ... etc

Any help/Info/Advise gratefully recieved!

[wrxfox]

i think its called a resonator box the large breather pipe goes to an idle control valve if you disconnect this the car will not run.the other little pipe goes to the bottom of the 3-port boost control solenoid dont think this is as important.

[Nutter128]

Thanks for the info, but why is it that Stevie12's RA hasn't got the lunchbox? On his, the large breather pipe is connected directly into the large bore hose behind the lunchbox, not sure where the small pipe goes though.

[BUZZ]

:blush: This is Probably a bit of a no-brainer for most of you chaps, but I'm not called "nutter" for Nothin' :2ponder:

I recently changed the old air box on My Wagon for a HKS induction doofa. but before doing so I had a peek at Stevie12's setup (just to be sure it was as simple as it sounded).

I noticed that just behind the MAF sensor I've got a large plastic "Lunch-Box" fitted, Where Steve's didn't. On first glance it looks like a fancy way to connect the Breather to the air intake, But I then noticed that there is another pipe that connects it to a couple of valve-relay-pump-looking thingys attached to the OS wing.

What is it? What does it do ? what's the other pipe for? Can I get rid of it without killing Scoob? ... etc

Any help/Info/Advise gratefully recieved!

what model year is the car, (i guess its about P reg) as these had breathers
newer classics didnt have the breather on the induction pipe

there are other ways of fitting them on!

[Scott.T]

All Pre96 cars had this 'lunchbox'.
It is called a resonator and tends to get removed when people fit things such as HKS or Blitz induction kits.
Some of these come with a length of pipe that does away with the resonator.

In standard form the resonator is connected to the induction path and also has a 15mm (or so) breather pipe attached to the front, and a 3mm vacum hose attatched to the side, which comes from the bottom of the boost control solenoid.

This 3mm hose needs to be connected as it feeds waste turbo bled air back into the system. This small pipe also contain a brass restrictor which helps to control the boost. If this pipe is replaced or the restrictor is removed, the car will overboost and trigger the fuel-cut. You will then be peeling your face off the dashboard.

[Nutter128]

This 3mm hose needs to be connected as it feeds waste turbo bled air back into the system. This small pipe also contain a brass restrictor which helps to control the boost. If this pipe is replaced or the restrictor is removed, the car will overboost and trigger the fuel-cut. You will then be peeling your face off the dashboard.

In answer to a previous response .. Mine is a '95 Import WRX Wagon

Is it possible/advisable to connect the small vacuum hose to another part of the induction path? As I recall, on Stevie12's RA the larger breather hose is connected via a branch-off on the 90deg hose that follows the lunchbox. My car has got the same branch-off, but it has been blanked off. So presumably I could re-route the breather with no problem.... right?

One thing I noticed today whilst tinkering ... Just above the Solinoid-doofa to which the vacuum hose is connected, there is another widgit that has a couple of wires coming out of it & it has another vacuum hose conecting it to the top of the inlet manifold. About half way it conects to a T-piece with one leg of the "T" connected to nothing. This can't be right ... can it ? ... What is the Widget and would it be advisable to block that "T" or connect the first vacuum hose to it?

Thanks for your input folks - much appreciated

Adi :cuckoo:

[Scott.T]

There's a few things the vacum pipes connect to on the drivers side wing.

There's the boost control solenoid which has a 2 wire connection and is a brass cylinder with 3 hoses attached. Top on goes to Turbo outlet, Middle One to Actuator and bottom one to Lunchbox thing (this is the hose with the restrictor).

There's the Pressure Exchange Solenoid, which is brown, has a 2 wire connection and one vacum hose attached. I think this hose is T's into the item described below.

There is also the map sensor which looks like it's mounted upside down, has a 2 wire connection and one vacum hose. This hose should track back to the inlet manifold. If this has been t'd into then it may of had a boost gauge fitted to it at some point. It should not be open, so would need blocking. Although if this was open I would expect it to throw a 'Check Engine Light' on the dash, it certainly does on the later car due to the ECU expecting a certain voltage output from the map sesnor at idle.

[Nutter128]

Hi Scott,

Sorry I've not replied sooner. I really appreciate the assistance/info you've offered, thank you.

Simon-aka-Trackstar Racing Services (The bloke who did all the work on Stevie12's RA) had a look and tried to explain it all to me, basically confirming all that you've said.

One thing I still don't quite understand, even though Simon did try to explain it to me, is the "T-Piece" with one leg swinging in the breeze. The "open leg" has a small brass ferule in it's end, which acts as a restrictor of some sort ...

... Sorry again ... totally lost the plot now .. thought I knew where I was going with this, but the ol' grey matter has Bug##red off to bed without me! I'll get a couple of pics together and try again later ....

Thanks again.

Adi