simonds1

Hi guys, I've got a boosting problem and I'm hoping somebody can help me with it. I'm gonna try not to bore you all to death, but I've been fiddling with the car a bit recently because I've been trying to put an sti 8 intercooler onto it, so I thought I'd better tell you what I've been doing incase anything I've done could've contributed to the problem. The car is a MY00 classic turbo 2000 by the way.

Right, so here is a short-as-possible explanation of what I've been doing to the car recently, and what's happened etc.......

First of all, I went over to a mates place and we changed my spark plugs cuz they were due a change, and then we fitted the sti 8 intercooler, along with a subaru standard oem dumpvalve (both from ebay).....



We went out for a spin then and the boost was leaking everywhere. Just hissing like mad and not accelerating. So we weren't sure if the problem was the intercooler having a leak, or the dumpvalve being ****, etc. So we decided the best thing to do was to pressure test my intercooler and go from there. So in the meantime, I put my original intercooler back on, but with the alloy y-pipe from the sti 8 intercooler rather than the samco y-pipe I had on there before, because we were just curious to see if it would make a difference.....



So that was lovely, got my boost back now, no leaks. Smashing. Buuuttt......the car seemed ever-so-slightly not as lively as it normally is. This is kinda hard to explain, but with my foot hard down it didn't really seem any different to before, but with very very gradual throttle movement, it didn't seem to go anywhere.....whereas before it was such a lively car. You so much as breath on the throttle and it would shoot off like a rocket y'know? Didn't seem to be doing that anymore, so I wondered if it was the y-pipe change that was causing it. This isn't the boosting problem that I've started this thread for by the way, that's yet to come! So anyway, today I put the samco y-piece back on because I wanted to see if that made the car more lively again. When I was in the middle of swapping the y-pipes over, I noticed this......



If you can't tell from the pic, that's the bleed pipe coming off my wastegate actuator. It had split, and actually completely come off. Now, I don't actually understand wastegates & boost control electronics enough to actually know what effect this would have on the car? I don't know how long this has been off for either, alltho I'm pretty sure one of us would've noticed it when we were changing the intercooler before. So I think it must've only just happened. So then wondered if it was this that might be causing the car to be not as lively as it used to be. So I replaced the pipe for a new one. But, as the bleed part of the forge wastegate actuator is quite fat compared to the standard one, I remember I had a real job to get the pipe on there back when I first got it. So I assume that's why it has eventually split, cuz it was so jammed on there like. So I ended up doing this.....



This was a much better fit, but I had to make the pipe a bit longer than it was before so it had a smooth bend in it rather than just a kink, which I thought would hinder the air flow and mess something up. So anyway, with this pipe now back on there, and the samco silicone y-pipe back on there aswell, I go out for a spin and now here is my boosting problem - I can now only boost at 12psi?!!? My car is mapped to boost at 23psi, and always has done exactly that. But yeah, went out for a spin and no matter what gear, or how harshly or gradually I put my foot on the throttle, I just get this.....



Smack bang dead on 12psi. The car sounds perfectly normal, no extra wooshing sound etc so I'm pretty sure there isn't a boost leak going on. My problem is that I changed two things at the same time - putting the samco y-pipe back on, and changing that little pipe coming off my wastegate actuator. So I don't know which one of those is now causing this, if any? So, I changed the pipe coming off the wastegate back to a single piece one and just forced it on there....



Went out for a spin again. Can still only boost smack bang on 12psi again. So I thought it might have been the y-pipe change. So I put the alloy sti one back on there and went out for another spin again. Still only getting smack bang on 12psi. What the hell have I done!?!? Or is it just a freak coincidence do you think? I don't really see what I could've done to cause this? Especially as I've now put it all back to how it was anyway? I did try to plug ECUexplorer in and record a log, but I'm getting a "cannot open live capture file" error and it just will not record anything. Grrrrr! Story of my life lol.

So yeah, that's it I think. Thankyou very much to those of you that've bothered to read this far - I hope I haven't bored you too much! Thanks in advance for your help guys

ianbott

That pipe is the but that tells the actuator to open the wastegate, when the pressure in the inlet manifold gets to the prescribed pressure it's counteracts the force on the springs inside the actuator.
What psi is your actuator rated to?
If that pipe hasn't been connected for some time then the actuator won't be being helped to open as it should.

simonds1

That's a very good question! My standard subaru actuator started sticking/jamming about a year ago so I replaced it for a forge FMAC4SUB adjustable one. When I first put it on, it had the standard green spring in it and it seemed to be giving way too early and the car wasn't boosting enough. I talked to Forge and they said it sounded like the spring I had in there wasn't strong enough and sent me the next one up (a yellow one) for free So I lobbed that in there and it was lovely and has been fine ever since. Forge haven't got a table saying what colour is what psi for their actuator springs for some reason, but they have got one for their dumpvalve springs......so assuming they're the same, then the green spring that was originally in there was rated at 5-15psi, and the yellow one that's in there now is 15-23psi. 23psi is what my car is mapped to boost at, so this should be okay?

simonds1

Just a quick update.....

Just been out for a spin with that pipe completely taken off the wastegate and the car is absolutely mental. Boosts 23psi no bother without me even pressing the throttle all the way down! Probably cuz the wastegate is now unable to open at all? In which case, why wasn't it like this before when that pipe came off?

Put the pipe back on and went for another spin. Back down to 12psi now. There is something weird going on here

I've got a spare boost control solenoid lying around so am gonna try that now, and will update in a bit.

simonds1

Okay so different boost control solenoid makes absolutely no difference either - can still only get 12psi. Any ideas guys? Or things I can try to get closer to an idea?

ianbott

23psi is a lot of boost really considering a standard is about 15psi.
You sure it was deffo mapped to 23? Not doubting just asking.

simonds1

Every single person I talk to about my car comments on how hight the boost is lol, but yes I am 150% sure that it's mapped to boost to 23psi, or 1.4bar. And has been doing that no bother for just over 2 years

ianbott

Maybe the tuner just pulled the pipe off! Lol only kidding.

dj219957

23 psi is 1.59 bar. thats a hell of a lot of boost. who mapped it?

simonds1

Yes you're right! Sorry. Bob Rawle mapped my car. I've just found an email I sent to him saying the car was boosting at 23psi and wasn't that a bit high, and he replied saying it's mapped to hold 1.4bar if it will, and my gauge was showing 23psi cuz it will be over reading slightly. So I put two and two together and had in my head that 23psi was 1.4bar. Doh So yeah, mapped to 1.4bar which is more like 20psi

simonds1

Another update, and I don't really know what any of this shows, but I'm hoping some of you will......

As I said before, with the pipe disconnected from the wastegate, the car boosts like mental - way too high. So that rules out a turbo problem, which is good I spoze. Changing the boost solenoid for another one I had here made no difference, but driving with it unplugged caused really violent fuel cut whenever I put my foot down. That might be perfectly normal? I have no idea. Then unplugging the pressure exchange solenoid (bottom thing on the bracket the boost control solenoid is attached to) and going out for a drive made absolutely no difference - still can't get more than 12psi. Could that mean that's faulty? You would expect some kind of difference when an engine sensor gets unplugged right? Another thing - when I unplugged the boost control solenoid I got a check engine light up, but when I unplugged the pressure exchange solenoid, I didn't

simonds1

Anybody? Plleeaassee?

simonds1

Right, nevermind. I have managed to sort the problem myself. For those of you who are interested (probably none lol), here is what was wrong......

I was looking around online and happened to come accross this.....



See the line at the bottom where it shows a pipe that contains the restrictor pill? Well that was one of the pipes I'd replaced when I'd noticed the split......so the restrictor pill was no longer there. Boom! So I found my old piece of pipe which I'd luckily kept, and butchered the restrictor pill out of it....



Then carefully slotted it into my new bit of pipe that was on the car.....



Boom that's it, car boost perfectly up to 23psi again! I'm so glad I saw that photo online otherwise I don't think I'd have ever found the problem. Can't believe how vital a TINY piece of brass is. Crazyness. Anyway, problem solved now. Hopefully this thread may be of use to someone in the future. Cheers guys

emlclcy

iTrader: (1)

Anyway, problem solved now. Hopefully this thread may be of use to someone in the future. Cheers guys

yes it has been and my engine isn't even running yet! I have a forge wastegate actuator on a td04 turbo. I bought the engine for a kit car project and it came with no turbo or plumbing. so a couple of questions, the restrictor pill comes with various size hole, just fit a standard one? and the froge wastegate controller arm, how tight should the wastegate be pulled closed as there is an adjustment on the wastegate, again this is all untested stuff just yet
cheers
carl