The "Hose 10" Mod - BE/BH

[Marky]

This got mentioned once or twice recently so figured I\'d chuck it up (if I\'ve gotten the workings behind it wrong, tell me)

What is it: It\'s changing the hoses to the same as a rev: d

What does it do: It gives you more boosty boosty and louder wooshy noises

Why do I want that: MORE POWER ARGH ARGH ARGH (tm Tim the Toolman Taylor)

Time taken: Approx 2 minutes +- 1 for fat/childlike hands

Quick explanation:

The way the legacy is setup out of the box, you will see a hose coming off the BOV, which then tees off to join to "hose 10" - and then feeds directly back into the intake pipe. The other side of the tee goes to the manifold as per normal. Hose 10 is (from memory) the bleed off from the wastegate boost control solenoid back to atmosphere.

Why is this like this? I have no idea. All I see is a bit of WTF subaru stahp what are you doing - the way I see it, you\'re bleeding off boost to the BOV, and directly out of the manifold straight back to the inlet. It also means that when in a vacuum condition, the BOV isn\'t getting a full vacuum signal - also not ideal. It might be a way to limit overboost? Whatever the story, it got changed with rev D anyway.

Result being - unresponsive /quiet BOV, potentially leaky BOV under boost, and in my case I genuinely thought it was something some monkey had done to my car aftermarket for whatever reason, not factory fitment.

Fix - remove the tee piece, run hose 10 straight to inlet pipe - that\'s IT

Result becomes: The 8 or 10 psi you see on primary tends to rise, and same goes for whatever you get on secondary. In my case it was causing the factory BOV to leak under boost and actually limiting boost on primary, regardless of what I did to raise it. The other side to this is that because you are applying pressure (from manifold) to the outlet of the boost control solenoid (hose 10) you are limiting how much is able to be bled off - when you give it a straight path, it will naturally bleed off more and tend to run higher boost.

Car becomes noticably more responsive, and if you have an aftermarket BOV it will get some volume now. My own experience also was it sorted the high / slightly erratic idle the car had as well - an open hose from manifold to atmosphere will do that I guess.

Risks... Uh, nothing? I\'ve never noticed any ill effects from this - however if boost is starting to go through the roof might pay to lower it, better safe than sorry, more is not always better

End result below - hose straight to BOV, and tucked underneath it is the hose number 10 going straight to intake pipe.

[Codex]

I wonder if this is why there was a delete on my bg gtb\'s supercharged pressure relief valve #1 solenoid so it doesn\'t release in a similar way o-o although bov in gen 2 feeds straight to inlet without a T

[ryn]

Please push for your own television show, good for the lols and info.

Going to give this a bash when I get outta bed....

[ryn]

It would appear one of my pipes ain\'t long enough.... Can you tell me what goes where and how etc from the pic. Cheers.

[Marky]

Even if you literally just block off that one coming off the blue T piece you\'ll be fine, that\'s all you need to do

It just tidies things up a little if you run a straight hose to the BOV and get rid the the T pieces tucked under the BOV recirc hose is all.

[ryn]

Worked a treat! Cheers man, makes such a noticeable difference.

[Codex]

That was quick ryn haha

[nickmcgill]

Ill be trying mine after work.

More broom broom

[Swindog]

Yeah mines already blocked as per ryns.

[nickmcgill]

I did a quick test over lunch.

Not sure if I did it properly or not, I have got some more hose there but just did this as a quick test.

Look about right ?

[nickmcgill]

The number 10 hose is actually the one that joins onto the metal line which goes the BBoD.

You can see if it in that picture just next to the BoV.

[soopersubaru]

Nek minit Ka boom!......ded engine lol

[Marky]

Ha, yeah that\'s what to do

Just maybe not with tape

And yeah 10 is the one you just hook direct to the intake - the one from BOV to intake doesn\'t have a number on it, I will name it "the bastard useless one"

[nickmcgill]

I\'m still somewhat confused with what to do with line 10.

It\'s currently still hooked onto that metal line to the BBoD.

Should this be blocked?

[Marky]

No

Plug it directly into the inlet pipe, just before the primary turbo inlet. See in my pic you can see it under the BOV - very far right of the picture.

Don\'t make me come over there

[Timmah]

 Marky said:

Don\'t make me come over there

That\'s what he wants.

[nickmcgill]

 Marky said:

No

Plug it directly into the inlet pipe, just before the primary turbo inlet. See in my pic you can see it under the BOV - very far right of the picture.

Don\'t make me come over there

SO basically.. I\'m connecting the hose that was disconnected from the T into hose 10 ?

From what I can see the hose from the T goes back to infront of the turbo intake.

[ryn]

I get a weird idle now, 700-800 fluctuating but seems all good. It\'s reallyyyy slow when doing it though. I\'m assuming I just haven\'t blocked the "T\'s" off well enough?

[Marky]

 nickmcgill']

[quote name='Marky said:

No

Plug it directly into the inlet pipe, just before the primary turbo inlet. See in my pic you can see it under the BOV - very far right of the picture.

Don\'t make me come over there

/quote]

SO basically.. I\'m connecting the hose that was disconnected from the T into hose 10 ?

From what I can see the hose from the T goes back to infront of the turbo intake.

No... you want to simply remove/block the one from the BOV line, that is it. Hose 10 is still going to the same place, in front of turbo inlet.

Ryn - try an ecu reset, that said if its not blocked right then it would explain a bad idle.

[nickmcgill]

Soooooooo I don\'t actually touch the number 10 line at all then?

Sorry I had been reading all the uklegacy threads which have confused me. ???

[ryn]

Correct nick. All I have done is removed the pipe between the two T\'s and blocked them up.

Cheers for the help Mark. It\'s been a great wee change.

[nickmcgill]

I drove it gently last night for about 10km with the tape on to test it.

Seemed to run allot better and dropped the idle by 100-200rpm.

Picked up some 6.2mm vac hose from repco before so I can do it properly later.

[ODB]

So you basically remove the T and run one pipe directly from BOV to manifold?

And the pipe that was connected to the bottom of the T you block it up and leave it connected but sitting there?

[Marky]

Yep

Just remove the tee-d off hose, put a straight pipe from mani to BOV (as per any other car), and from memory down at the inlet pipe there\'s a plastic T for the hose you removed and 10 to both join to the inlet pipe - just whip that out and put 10 straight onto the inlet instead

[Codex]

If you want to block it off use a plastic insert and just use wire heatshrink over the end instead of tape, seals and is a lot more durable

Or do what the previous owner of my car did and use crap loads of electrical tape and rusty screws...