Restrictor pill size?

[abakja1]

I bought a used 2011 LGT that had a grimmspeed ebc before for tuning and previous owner put back stock ebc.

 

Does anyone know the size of the oem restictor pill and where i can get a Replacement?

 

I searched everywhere including this forum and thru subaru parts websites and could not find an answer. Subaru parts website led me to a diagram with the right hose, but when i click on it, it tells me i have to purchase the whole turbo itself.

 

https://parts.subaru.com/p/Subaru__/49226822/14411AA760.html

 

I feel that the car is not boosting as it should and saw only 8lbs of boost only and read thru the forums thru searches that it could be a missing restrictor pill if owner did not out it back in the hose.

 

Any help appreciated.

[dgoodhue]

I don’t think their is a restrictor pill. IIRC the t vacuum line section that went from the boost control solenoid, turbo to wastegate. The hose going to the wastegate was smaller. Your tune may be set up for the grimmspeed 3 port EBC and not the stock 2 port EBC solenoid.

[dgoodhue]

The parts catalog sort of makes it looks like a restrictor. I think the parts are the following for the vacuum line assembly, but I am not 100%.

 

22321AA110

807506161

16385AA030

[FLlegacy]

I don't recall there being a restrictor pill in the line when I installed my EBCS. What is your boost target set at when you are only getting 8 psi? IIRC 8 psi is stock boost for gears 1 and 2.

[stewdogg]

I can confirm that there is indeed a restrictor in the stock boost control hoses. I have the stock setup sitting here in front of me on the desk, from switching out to the 3 port EBCS.

I have to run out right now, but can stick the calipers on it to measure it when I get back later... I guess I'm not sure if they go by outer diameter or size of the hole...?

[abakja1]

I don't recall there being a restrictor pill in the line when I installed my EBCS. What is your boost target set at when you are only getting 8 psi? IIRC 8 psi is stock boost for gears 1 and 2.

 

Boost pressure was 8psi in 2nd or 3rd gear pull. I just felt that the car was underpowered, but i knew it needed maintanence done.

 

I just bought the car 2 weeks ago, and at the time it needed 60k work a s spark plugs and fluids havent been changed yet except of course the engine oil.

 

After i put in new plugs and gapped for turbo, it felt stronger, but nut felt the turbo not coming on as quick or as strong as it should.

 

So, full boost (i flashed AP stage 1 since installing Invidia q300 catback) should be 15 psi peak i believe. Also, i wont see this peak boost unless in 3rd or high gear correct? Also, would peak boost in 1-2nd gear still be 8psi?

 

I am going to change oil today, so ill look to see if I have a restrictor pill or not.

Lastly, if a Grimmspeed 3 port was taken off, what should have been put back on or done to go back to oem spec other than the oem bcs and restrictor pill should there be on?

 

Will wait to see what size pill is so I can buy just the pill if its same as wrx/forester or sti.

So far, all searches for pill so i can just buy it or the entire vacuum hose and T with the pill for the 2011 lgt has gotten me nowhere. References or info for 5th gen on nasioc and google turns up nothing. No threads or direct discussion on the pill size or oem part number on lgt.com came up either.

Edited August 2, 2019 by abakja1

[stewdogg]

This is a pretty good read on the restrictor pill/boost control situation:

http://share.subiefiles.com/subiefiles/technical%20reference/BoostControlSystemExplained%20v1.01%20Cobb%202006.pdf

 

I measured the inner diameter of the restrictor and it's 1mm/.040".

 

If you need the outer measurement as well, let me know.

[abakja1]

I can confirm that there is indeed a restrictor in the stock boost control hoses. I have the stock setup sitting here in front of me on the desk, from switching out to the 3 port EBCS.

I have to run out right now, but can stick the calipers on it to measure it when I get back later... I guess I'm not sure if they go by outer diameter or size of the hole...?

 

Can you post pic of the hose and restrictor pill?

[abakja1]

So i figured it out today as i had to change my oil anyways.

 

Just to confirm, there is a restrictor in the hose.

 

Problem was, the vacuum lines were hooked up backwards as the restrictor pill was on the wastegate side. Previous owner or mechanic who put oem boost control back did it incorrectly.

 

I unplugged the hoses and arranged them correctly to how they should be.

I Hope this solve the problem as a quick drive around the block revealed the turbo getting on boost now. Just didnt have the room to do a 3rd or 4th gear pull since im in a rural neighborhood.

 

Thanks everyone for the help.

[dgoodhue]

With the Cobb AP OTS tunes it shouldn’t be limited to 8psi in 1st and 2nd gear.

[abakja1]

With the Cobb AP OTS tunes it shouldn’t be limited to 8psi in 1st and 2nd gear.

 

From reading the threads on the topic, if you have the vacuum lines hooked up wrong like in my case with the restrictor pill on the wastegate side, it was the reason i saw only 8 lbs of boost.

 

Without the restrictor pill limiting the amount of air to the wastegate, you will only see 8lbs of boost no matter what gear your in or if you have a cobb tune.

 

So I read in these forums,....

[cww516]

I think what he's getting at is that the Cobb OTS tunes have the same boost target in all gears, as opposed to 8psi in 1st-3rd and 12psi in 4th-6th like the stock tune. Shouldn't take a high gear pull to verify your fix- you ought to see it get above 8psi if you give 'er the berries in 2nd, and that's a little easier to get away with in most locations.