Restrictor pill location gen 3 AUD B4

[PUREBROWN]

Hey guys i need some clarification i tried searching and going through my manuals but every diagram is different to a degree

On the primary turbo there is a line going from the diaphram (wastegate) side to the outlet side of the turbo with a T piece in it and a .8 restrictor. What i want to know is which side of the t piece is that restricter ment to be? The wastegate side or outlet of turbo side?

I had been getting 11 psi primary/secondary no codes no hiccups. But i knew secondary wasnt ment to be that low. Now out of dumb luck i ordered the .8 restrictor to do the #1 hose mod but after cleaning solenoids and a reset vod was non exsistant with maybe 1 sec changeover happydays. When part came it came with hose and t piece and was the primary turbo t piece line so i thought what the hell ill change it. I pulled out the old noteing orientation of restrictor ( on the top side near wastegate diaphram) took the car for spin, now only 6 psi on both....dammit.

I then looked at diagrams and found one with pill at the bottom near outlet so i changed it over and set it with the pill towards outlet and bottom of t piece . Car is 11 psi primary and 17 psi secondary......HOLLLLY SHIIEET!. After wiping smile of face i need to know is this correct ? The orientation and the stock boost specs for this car before i blow **** up???

On a side note i also found gen 3 diagram with no T piece and the line going from primary wastegate to wastegate solenoid and the outlet line of pri turbo going to wastegate solenoid valve outlet? Is this the correct way ???: /

[Rosssub]

In this pic the white paint dot shows where the restrictor pill should be:

The setup you've seen without a T-piece might be an aftermarket setup (MBC/EBC).

[Rosssub]

Also see post #15 in here, (restrictor pill locations).

http://clubsub.org.nz/forum/showthread.php?35720-B4-Vacuum-diagram/page2

[PUREBROWN]

Thanks ross well seems someone at subaru had a brain fade putting it back together for the previous owner so thats one mystery solved.

the diagram with the alt routing was straight out of workshop manual so i dunno but anyway is 17 psi too high???

[Marky]

Boost is about normal, this is where you'll start to hear it pinging mind you. The AUDM model is renowned for it, they even heard it during road tests when they were brand new vehicles

The restrictors purpose is to reduce the flow needed to be bled off by the boost solenoid. If you put in a larger or smaller restrictor, you end up with less or more boost as a bigger % of it is bled off

[PUREBROWN]

Thanks mark yeah the ping is a concern i havnt heard it yet but will be keeping an ear out for it cheers

[PUREBROWN]

Ok been driving around with average ambient of 20 and no pinging evident what is evident is i hit 16 / 17 psi and it tends to bleed off about 3 psi or less with hard acceleration. I have modded the #10 hose , is it likely to be relief valve not holding its pressure or the boost solenoid retarding it? I have factory setup all stock. Was thinking of getting GFB 9000 if the relief valve isnt holding what it used to. Side note when i was running 11 PSI with secondary it was solid as

cheers

[Marky]

It shouldn't bleed off at all, and the bolt on factory BOV's don't have a reputation of leaking at all

If it's retarding boost due to knock it normally pulls it outright, not tailling off with RPM's, and it's a last resort after pulling all the timing it can too

The primary boost can be a bit oddball at times due to the pre-spooling of the secondary, that might explain it dropping a bit with foot flat compared to part throttle. When on secondary it *should* hold right out to redline

If you think the BOV might not be holding pressure, you can test it by blocking off the valve outlet itself (a D cell battery just happens to fit in the recirc pipe perfectly, fyi) to rule it out