The_Bronze Posted April 11, 2014 Share Posted April 11, 2014 So, project 'rolling money pit' is coming on now (I kid, asides the sump everything else has been my choice!). I've noticed since I had the car that it always felt quite quick but you had to wind it up to get any decent go out of it, not like my old Impreza was. I also noted that while it could shift along ok it's never really felt any faster than my old Golf VR6 or my E39 535i. Boost gauge fitted, 0.5bar, disappointment! :( I've read that from factory they should boost at around 0.9bar, so I delved into various forums and replaced the heat hardened vac line to the T piece (between the boost solenoid and the actuator) and then took the short pipe off the turbo body to look for the 'restrictor pill', which I've read for the euro spec (ie UK Turbo) should be 1.2mm internal diameter. I looked inside and saw something, so flipped it out with a screwdriver, it looked like the bottom of a sawn off banjo bolt and was approximately 3.5mm in diameter, boost issue probably found! I fitted a 1mm welding tip in addition to said new vac line and took the car out, noticeably quicker, more urgent, and with a noticeable increase in low down torque. I'm boosting to just a little over 0.7bar now which is an improvement but still lower. Also, does the restrictor pill go by the T piece or at the other end? I assume it could make a difference! my is by the T piece currently. I need to check the actuator is working correctly and not sticking or opening prematurely because of a weak spring next. One thing I noticed mine doesn't do is that tiny little fast 'chiff' noise the dump valve makes when making quick foot down short shifts, my standard old Impreza did, and as I mentioned mine started randomly doing it then stopped again. It also sometimes feels when I'm slowly accelerating at part throttle it's quickly surging and backing off but the boost gauge doesn't fluctuate whilst this happens, it's only very, very slight but I can just about feel it. There's also a slight uneveness at idle but again it's only very slight. I've cleaned out the solenoids out with carb cleaner and also just did the ECU reset procedure http://www.subaru-impreza.org/forum/electrical-including-ice/11204-ecu-reset-how-many-different-methods-there.html - bottom of page. Here's a pic of the 1mm welding tip and the whatever the hell it is that Subaru definitely didn't fit: From what I understand the earlier 3 port solenoid set up benefits from enlarging or even removing the restrictor, the later type (MY97 and on I think but don't quote me) benefits from decreasing the restrictor size, wires crossed maybe? I took the car out just now before posting, holy hell, boosting at close to 0.8bar now (according to my ageing Speedparts gauge) and it's transformed! will report back on the slight surge thing and see if it goes away over due course. 1 Quote Link to comment Share on other sites More sharing options...
quit Posted April 11, 2014 Share Posted April 11, 2014 Yeah boost leak can be a pig to fix but yeah you should **** all over a slow arsed vr6 lol Quote Link to comment Share on other sites More sharing options...
BlackBosh Posted April 29, 2014 Share Posted April 29, 2014 Whats this pill you refer to never checked the boost on mine but would be awesome if a few standard psi were to be had from her Quote Link to comment Share on other sites More sharing options...
The_Bronze Posted May 1, 2014 Author Share Posted May 1, 2014 Whats this pill you refer to never checked the boost on mine but would be awesome if a few standard psi were to be had from her I only stumbled on it by chance myself to be honest! From what I understand, the earlier 3 port solenoid cars (pre '97 I think?) had a boost restrictor, but the less restriction on a 3 port car means more boost, so either larger 'pills' were fitted (a little piece of brass rod with a prescribed size of hole drilled through it) or the 'pill' was completely removed. For the later cars fitted with the 2 port solenoid system ('97 onwards, though from what I've read the odd exception does exist) the reverse is true, the smaller the hole and therefore greater restriction in the 'pill' the more boost will be achieved, though this does need to be monitored on an accurate boost gauge. The 'pill' is located inside the pipe marked as '2' in red: For clarity's sake I've also included another view of the turbo and vacuum pipes I can't take credit for the photos, I just ripped them from a google search! This is all assuming the car is standard and not fitted with aftermarket bits and bobs! If your car doesn't have the right size or a pill at all I've got a fair few left over welding tips I bought so let me know! 2 Quote Link to comment Share on other sites More sharing options...
BlackBosh Posted May 6, 2014 Share Posted May 6, 2014 Will check on that but the way mine goes it can't be on anything less than standard boost (mates scoob ids and other jap cars lol) I just like to absorb info like a sponge Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
Gambit Posted May 7, 2014 Share Posted May 7, 2014 Some good info there mate. And taking as much in as possible is always the best way ;) Quote Link to comment Share on other sites More sharing options...
savage bulldogs Posted May 7, 2014 Share Posted May 7, 2014 I did a bit of research on the restrictor pill prior to my first remap and found this list which states the size and position for classic oe pills I don't know to much about the vacuum system tbo but , I think the restrictor pill is fitted to help stop boost spike in the oe map when the engine is under different loads (ie different gears or going uphill ect ) MY93-96 ... 3 port*solenoid*2.0mm restrictor fitted into the vent pipe between*solenoid*lower port and intake MY97 (Euro) ... 2 port*solenoid*1.2mm restrictor fitted between the turbo and the tee piece MY97 (JDM) ... 2 port*solenoid*0.9mm restrictor fitted between the turbo and the tee piece MY98 (Euro) ... 2 port*solenoid*1.2mm restrictor fitted between the turbo and the tee piece MY98 WRX (JDM) ... 2 port*solenoid*0.9mm restrictor fitted between the turbo and the tee piece MY98*Sti*4*... 3 port*solenoid*1.5mm restrictor fitted between the turbo and the*solenoid*adjacent to the*solenoid*top port MY99 (Euro) ... 2 port*solenoid*1.2mm restrictor fitted between the turbo and the tee piece MY99 (JDM) ... 2 port*solenoid*0.9mm restrictor fitted between the turbo and the tee piece MY00 (Euro) ... 2 port*solenoid*1.2mm restrictor fitted between the turbo and the tee piece MY00 (JDM) ... 2 port*solenoid*0.9mm restrictor fitted between the turbo and the tee piece 1 Quote Link to comment Share on other sites More sharing options...
BlackBosh Posted June 12, 2014 Share Posted June 12, 2014 So this has now been useful to me sort of, i fitted a boost gauge and was seeing 13psi. I have since swapped all the vacuum hoses and only getting 9 sometimes 10psi. Then my mate asked me about the restrictor pill (which I'd forgot about) and i read somewhere on my05 it will go between the turbo and the t-piece so i put it back in and nothing still getting 9-10psi with a wobble at full chat. Also slightly annoying is no more flutter though I know this will come back with full boost so help please Quote Link to comment Share on other sites More sharing options...
Rick 2014 Posted June 23, 2014 Share Posted June 23, 2014 I think ive a bit of a boost problem as well.The long hose in your diagram number 3 seems rock hard and feels like is crumbling inside.Number 1 has nothing in it and number 2 has something in it I don't no quiet what its surposed to be lol Quote Link to comment Share on other sites More sharing options...
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