Brass restrictor pill
 

Need some info to be honest.

Now, I know you can get sizes from 0.8~2.0mm, I've spoke with a Subaru main dealer, but they are unsure, I then spoke to Area52 who have said they have no idea, I also spoke to scoobyworld who also said the same.

I've also been told that the brass pill sits on the pipe coming from the boost solenoid to the T-connector, rather than the pipe that comes off the main turbo housing to the T-connector.

The car is a MY96 (dec 96) STI V3 Import. Pre-facelift bonnet etc, however it's of course got the V3 sti engine, which is facelift.

So...which pipe should I be checking, rather than checking every pipe due to in-accurate information.

And on average what size should I need for a car running the following;

Standard airbox, green cotton filter
Belmouth downpipe 3" to 2.5"
Full decat afterburner vortex exhaust
HKS SSQV BOV
STI V6 TMIC

I can get hold of a 0.8mm & a 1.0mm today, and get them posted to me. Although the scoobie main dealer thought it may be 2.0mm...

I don't mind getting a random size as it may have to be drilled anyway, but I need to know what pipe for a V3 sti import as I don't want to put a brass pill in the wrong place, and if anyone has a good idea on size then it would be great...as it currently doesn't have anything in any pipe at all.

So...any help is welcome.

:s

Ive seen people mention these "pills" before, but what actually do they do?

Quite odd really on the early cars they prevent overboost and on the later (facelift) they prevent underboost iirc.
To the OP if it has a 3 port boost solenoid then

Boost Solenoid Plumbing

2 port i have no idea sorry.

Part numbers are :-

22326AA090 (Standard Pre96)
22326KA120 (Standard Post96)

Hope this helps I recently changed mine on mine as it was missing on my 1993 wrx and was overboosting like anything.

o i forgot i got 2 links for each system.

pre96 is :- Boost Solenoid Plumbing

and post 96 is :- How Subaru's Factory Boost Control System Works v1[1] 01

It's a brass ball (but similar to a pill shape) with a hole in the middle, now the hole can be a different size and it allows air to pass threw, i.e. your boost, the greater the hole the more boost, go to far and you loose boost as the pressure drops, have the hole to small the the pressure is to great and will over boost, if the boost pill blocks then you can blow something up :) strange little thing to be honest!

Got a 0.8mm & a 1.0mm from scoobyworld just to try out as a temp until I get my info off the vin plate.

I take it mines post 96? Being a dec 96, V3 sti...

If the pills are the wrong size I suppose I can drill them a little bigger!

Thanks for the help :)

Goes along way.

Ahh right, so this does the same kinda thing as a boost controller?

To sum it up yes, without it you have low boost. With it you can increase or decrease your boost depending on the bore size. Which is why i've gone for a 0.8 & a 1.0, as the car isn't standard I've been told by Area52 I may need a different size pill, so will try the 0.8 and see if it overboosts, if it does i'll change to the 1.0. Can't always drill the hole to make it a little bigger as well :)

Will be reading the links once i'm back home from work.

@ariser

What size was your pill for a pre96? also can you remember the size for a post96?

Got my parts from a subaru supplier, rather than main dealer.

Right..my old wrx import MY95 had a 2port, my current has a 3port.

However, what do the MY97's run?

Need to define which one mine is lol, confusing myself I do believe!

I would guess that mine falls into the 1993-1996 group?

Forgot to add, mine is running a VF23. Not a TD05.

Just had a look, got a 3 port boost solenoid, but I don't have a resonator box on the car and the air-intake pipe is going back onto the main block of the engine...near the HT leads.

Is this correct?

Cheapest way to get the pills will be MIG welding tips, cheap and come in many sizes.
We used one on mine when mapping it as someone had changed the pipe work and binned the pill on mine.

I must admit in the end I swapped to a 3 port, never had a problem since

im not sure of the size of the hole as i fitted mine on my 3 port setup to stop hitting 1 bar at 4000 rpm in 3rd and fuel cut off lol my bottom vacum off the solenoid goes into my apex power intake

Hello, I know this is an old thread but I need a Brass Pill Restrictor, and I see that folk have used a Mig Tip.

My car is running without one, consequently very little boost, according to my ecu reading its currently at around 0.75 bar, how true this is i dont know.

I think reading up on the internet it should be at 0.9 bar which doesnt seem far away from what it is now, but my car currently feels very sluggish.

So will the pill make a big difference in power 0.75 vs the 0.9 bar?

and what size hole should it be on my car (UK300 2001plate)?

Can I use a Mig Tip, I've seen these on eBay for example in 0.6mm,0.8mm or 1.0mm holes

Mig welding tips for MB15.(pack of 5) Free P&P on eBay (end time 16-Sep-09 16:17:03 BST)

I used a Mig welding tip in mine after changing all the vaccum pipes and losing the brass pill, i fitted a 0.8mm welding tip and it worked fine, boosted to 1.35bar that it was mapped to the same as it did with the orginal pill fitted, with no pill i only got around 0.7bar.
Few weeks later found the orignal pill and re-fitted that.

UK300 PRODRIVE: What do you use to read the boost from the ECU?

Anyone knows what pill size comes in the STANDARD '03 STi ProDrive?

Unsure about your question on pill size for the 03 STI, but i do recall seeing a thread on here somewhere with a listing of cars and std pill sizes... Id be intrested in knowing this too. I;ll have a look and get back to you.

On the Ecu reading, im using a digital PSI3 pod mounted. Seems to be a very good bit of kit, but the compnay that makes them no longer exists, so you may be better asking on here for alternative readers.

Just bought 0.6, 0.8, 1.2mm mig tps.... I'll try the largest first and get some boost readings, this should give me lower boost.... safely does it

If you have a 3 port fitted then the pill should defo be put in the bottom ports vac line. This vac line can be left hanging in engine bay or recirc'd back to intake pipe. If the former then block the opening to intake pipe (obviously). The pill for the 3-porter should have a 2mm hole (according to the info in Scott T.'s website: http://www.polarperformance.co.uk/Boostsolenoid.html)

If you have the 2 port, then the pill should be put in the short length of vac line betwixt comp nozzle outlet and T-piece. Don't know the hole size for the 2-port's pill though...


See the images in ariser's post #5.

Appaantly the restrictor plays two parts, on pre 96 the bigger the hole the higher the boost, on post 96 its the other way, the bigger the hole the lower the boost... dont quote me, i read it somehwere....

So I have just been out in my car 2001 UK300 Prodrive with a 1.2mm pill and the boost predomintly stayed below 0.85bar, however in second gear i got a blip to 0.95bar.... thus i have asked my good friend engineer Andrew to bore a hole to 1.4mm and then i can test this out... I'll keep you informed.

My question i raised with Scoobyteknix is that my boost readings are through a PSI3 ECU reader, is this a good source of information, and how accurate is it? So a trip onto Scoobyteknix where we can run both ecu and plumbed boost gauges side by side to see the accurateness.

Sorry, UK300, the info in my post was meant for the OP...

53 plate UK Blobeye Wrx.
After fitting a Boost gauge my boost was an indicated 10 Psi Held @ Wot, I believe from info on here that i should of been nearer 14 Psi..

So after looking at the above thread i fitted a 0.8mm welding tip & went for a road test, as far as i could make out :D (As there is always some slow Joe infront of you when you want to test) This 0.8mm restrictor pill increased Boost to approx 16 Psi...

I then drilled it out to 1mm & again, Thanks to the slow Joe's :D It now appears to be boosting to approx 14 Psi ....

So i will leave it at that a while & see how it drives over a few hundred miles, You can occasionally feel the Ecu doing it's thing & pulling back the Boost @ certain throttle positions, This is also clarified by watching the Boost gauge , when possible ..
Dean

I only used a mig tip to try find the problem, this was done with the mapper in the car keeping tabs on everything.
I took all the oem pipe work out and fitted a turbo smart 3 port to mine in the end and it solved all the problems.

My newly built engine only covering just under 1700miles with a 1.5mm pill restrictor is not boosting as what i would deem as normal, but then i havent told the garage this yet so they may be able to sort it.

I went for a run when the car was warm revving the engine to just short of 6'000 in 1st, 2nd & 3rd. I could not get the boost to peak over 0.85bar for a 10min run which is kind of good right?, the suddenly doing the same kind of revving on my way home from work i peaked once to 0,98bar... why is this? Am i just short of a mapping?

I will await any advice, but ultimatly I will speak to Brian at scoobyteknix for advice and eventually get the car mapped if i dont decide to sell it... anyone?

The Ecu will/does pull boost back in 1st & 2nd Gear & will stop you achieveing maximum, This is built in by design.

As for it peaking slightly higher on another day, That could just be down to your right foot or atmospheric conditions Etc. :D

Dean

Same day, conditions may be different, as it was 10pm at night.

I also got a peak tonight (30mins ago) in either 1st or 2nd gear. I came out of a junction 20mins after car started so all was nice and hot, I blipped it in 1st to around 6'000 then 4'500-5'000 in 2nd, and as i was watching where i was going i dint look at the peak boost reading until i had steadily run a further 300yards and noticed that it read 1.02bar...

Has anyone any idea what size pill restrictor to use in a MY01 Prodrive WRX. I have a 2001 UK300 Prodrive.

Think mapping is the only way to sort it, anyone recommend a good reputable company?

Jolly Green Monster, Simon, Gets V Good Votes on here, as does AndyF Andy Forest, Depends where you are, AndyF is in Edinburgh & Jgm Midlands. I have only ever used AndyF, But my next port of call will be Jgm..

JGM
www.jollygreenmonster.co.uk

Andy Forest
AndyForrestPerformance

The Fish & Chips @ Port Seton Chippie are the best i have tasted :D

Of course there are many others on here, all with good reputations.

Dean

JGM is based in Kent. But he obviously travels to do mapping, so a large percentage of the time will be in the general core midlands area, I suspect.

If you're prepared to travel a bit, or find yourself in the midlands area at some point, then don't rule out Paul at ZEN in Wellingborough - another mapper extraordinaire...

what about my 93 wrx will it have a restrictor pill thing as i changed my pipes to samco and if i had then ive binned it

Quote:

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Originally Posted by scoobwrx94import (Post 8968471)

what about my 93 wrx will it have a restrictor pill thing as i changed my pipes to samco and if i had then ive binned it

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As far as im aware pre 96 cars used the restrictor in a different fashion tp post 96 cars:

Pre 96 the pill with a smaller hole reduce boost
Post 96 the pill with a smaller hole gained boost

If you running with not pill then you may be running with very very high boost?!?!?

Best referring to ariser’s post below:

:( Yeah, it would have been in the bottom vac pipe:-

http://www.polarperformance.co.uk/Boost_Control.jpg

now that ive binned mine by mistake looked everywhere its gone would i be able to just plumb up a adjustable boost as ave got a turbosmart one lying in my garage???