The saga continues: I can't even come close to 7 psi. The one, and essentialy only, problem is that I'm only getting 3-4 psi of boost. Here's a summary of all the things I've checked or had done at the shop.
1) Wastegate adjustment pin dialed way down/in (me)
2) BOV set near max "Hard" (me)
3) No vacuum leaks found (me)
4) Exhaust leak(s) found and fixed (shop)
5) Field SFC appears to work fine (me)
6) J&S knock sensor functioning ok (me)
7) TPS sensor(s) functioning ok (shop)
8) Idel-air sensor reconnected (shop) Don't ask. http://www.i-club.com/ubb-files/frown.gif
9) Oil leaks fixed (shop)
10) All ECU error codes cleared/addressed (shop)

I'm now at a total loss as to what to do next. Frankly unless one of you technicians out there can diagnose the probelm without even seeing it, I may just have to drive the d@mn thing 6+ hours to some place like Rallispec to have them work their magic.

Any ideas?!? Pleeeeeaseeee? http://www.i-club.com/ubb-files/wink.gif
-Scott '98 RS, theoretically Stage 2

[This message has been edited by Molez93 (edited May 06, 2000).]

What do you mean when you said the wastegate pin is in? Is it an external wastegate with anjustable rod? Or is it the screw that you turn in on top of the diaphram?

You definately have a vacuum leak somewhere. I would check the line hat runs to the top outboard port on the wastegate - it has a nasty habit of developing "slits" sometimes (at least on my car).

Ver.III- It's an external wastegate, but it also has a screw on top of the unit to adjust between 5 and 7 (or 8) psi. At least it SHOULD. http://www.i-club.com/ubb-files/wink.gif

Adam- So do you have any suggestions as to how to fix such a vacuum leak? Should I take it to a the race shop that installed it inspite of the fact that mine is the one and only Impreza they've worked on? Or, is it a no brainer that I can tackle with the right rubber hose? I don't quite know what a "slit" is, but assume it's a lengthwise crack in the tubbing. My car has only produced 3 psi from the start. So if it is a slit, it's been that way since the install. FWIW- I only checked the intake through the throttle body for vacuum leaks so a leak between the wastegate "boost" nipple/port and wherever else is VERY possible.

Generally speaking, what is the likelihood that the Turbonetics wastegate/deltagate that came with the kit might have some mechanical problem with it? When talking with a local DSM turbo "expert" at today's Finger Lakes/Rochester, NY autocross, I was explaining to him (Like I did to start this thread) and he seemed to think it might be a wastegate malfunction.

Thanks again guys! http://www.i-club.com/ubb-files/biggrin.gif
-Scott

Edit= Yet more typos...Good thing I wasn't an English major. http://www.i-club.com/ubb-files/wink.gif

[This message has been edited by Molez93 (edited May 07, 2000).]

I would definately take a close look at the wastegate. Checking the vacuum lines should not be too tough. Either something is horrible wrong witht the turbo itself (unlikely, because you would know if the turbo was that bad) or something is causing the wastegate to open too early.

If its the Deltagate that I am thinking of. Maybe the diaphram inside is ripped or it is not sealing properly. What happens if you turn the BOV counter clockwise all the way out? Are you sure all the hose clamps are tight? Is the exhaust restricted?

Try this too...unhook the BOV vacuum line. Now work the throttle under the hood and put your hand over the discharge tube of the BOV and rev and let off the engine to build boost. Under throttle, the BOV should not let any air past itself. If it does, try turning the adjustment screw until it doesn't leak air under boost (high rpm ramp).

Mark
99' RS-t

If it is not the BOV, it is the wastegate setting or pressure source control vacuum line for the wastegate.

You may want to check which BOV nipple you are routing the manifold signal to. You want to use the one on the top of the BOV. The other slanted nipple is left alone and referenced to atmos. Just a thought...

shiv

Thanks guys!
One of the few things I'm certain of is that the lines on the BOV and Wastegate nipples are connected correctly. I'm far from sure about leaks or manfunctioning equipment.
At least I've got a few good things to try, I just need more spare time. http://www.i-club.com/ubb-files/tongue.gif
-Scott

You can take a bottle of ether and spray around your vaccuum lines. Don't use alot. If you have a vaccuum leak your motor will rev up.

Man am I sick of low boost...
I checked and replaced the hose from the turbo to the wastegate. Still next to no power. I took the wastegate off as well, frankly it doesn't look like the dump valve has opened up even once. Based on a how the exhaust-Y meets the turbo down pipe, I'm thinking that the shop may not have completely fixed any leak that was present. What I *do* know is that they did improve the fit (if they didn't eliminate the leak) so I would have expected the boost to increase at least slightly. Right?

Any MORE thoughts?
-Scott "Approaching Total Frustration" Moller

Scott,

I have been following this thread since the beginning, and it is heart-breaking.

I spec'd all of the components of my turbo kit myself, and overlooked most of the install. I know it is a completely different setup, but the workings of a turbo system are almost universal...

If you are not building boost past 3lbs, this could mean that the turbo is not spinning quickly enough to build more boost, or there is an air leak on the compressor side somewhere...

Since you have stated numerous times, all the charge pipes, and hoses are fine on the compressor side, we will rule out a major air leak on this side. This only leaves the exhaust/turbine side...

The most likely cause of this lack of boost could be the wastegate opening way too early and letting out all the exhaust gases skip powering the turbine.

The simplest way to test the wastegate problem is to disconnect the hose to the wastegate and run the car under light throttle.

NOTICE: BE VARY CAREFUL!!! IF THIS WORKS CORRECTLY, THERE IS NOTHING TO STOP THE CAR FROM BUILDING BOOST! DO NOT USE FULL THROTTLE, RATHER BUILD UP BOOST SLOWLY AND SEE IF IT GOES HIGHER THAN 3LBS.

You see, the exhaust has to go somewhere after it leaves the engine. It is up to the wastegate to regulate the amount of exhaust that spins the turbine. The wastegate has mechanics inside that make it open when a specified amount of air pressure is applied (from the vacuum hose that runs to it). When you disconnect the vacuum line, it never senses positive pressure, and will not open. This leads to alot of exhaust gases spinning the turbo, and mucho boost being created.

If you unhook the wastegate vacuum line, and it still does not build boost, the wastegate is bad, there is an air leak on the compressor side, or there is a major exhaust leak prior to the wastegate(which you WOULD hear.. so i doubt it.)

Think of it this way (very simplistic)... it is basically a closed system after the air filter, and before the muffler (assuming you are not running wastegate or BOV vented to atmosphere... Therefore the air going in through the intake, needs to leave the exhaust. There is only 2 ways: 1)through the downpipe, after powering the turbo, or 2)through the wastegate while skipping the turbo.

hope this helps, in some way... http://www.i-club.com/ubb-files/wink.gif

michael

feel free to email me privately or respond here..

Thanks Michael.

Actually, I considered disconnecting that line but figured it was so easy that there must be something wrong with even trying it.
When I replaced that hose a couple days ago I noticed a burn/ wear hole that suggested to me that OVER boost should have been a probelm if that hose were the only issue. I am hoping (in a twisted sense) that the wastegate is the issue....whatever.
I'll have time to check stuff tonight, maybe even post relevant findings tonight.

Assuming I need to try replacing tha wastegate, I won't even be able to TRY taking off the necessary plumbing until Sunday.
Thx-Scott

Michael beat me to my suggestion: Try running the car *carefully* with the vacuum line to the Turbonetics wastegate disconnected from the wastegate and just temporarily plug the line with a screw or nail.

If you don't plug the line you will be running with a vacuum leak and the car won't run very well (may not even idle).

Running with the wastegate disconnected from the intake manifold pressure should make it so that the wastegate never opens. This means it will boost to the sun. I accidentally did this on mine when I first put on the boost controller. I connected it wrong and watched as the boost guage climbed to almost 20psi before I backed out. Ping, ping, ping!

If under these conditions you are still not making boost then it is not vacuum related. It is either the turbo not spooling up (can you hear the turbo spool up?) or the Turbonetics is opening way too early for some mechanical reason.

Have I heard the turbo spool up? Maybe. I'd swear I hear it spooling at least a little, but it's nothing like what I get in my 300ZX or my 'old' MR2 turbo. The boost guage does read as much as ~3 psi under throttle.

-Scott

If it turns out that it's not your wastegate, I would look for an exhaust restriction of some kind. I had the same problem in a car I bought from a guy a while back. Turns out he had hit something and smashed the exhaust pipe under the car. It wouldn't make more than about 2-3 psi. Fixed the exhaust, no more problem.

If you aren't sure that the turbo is spooling, then it probably isn't. I don't know about you other Minnam guys, but I can hear mine quite nicely. No, its not like an F-16 taking off, but it is definitely audible. A nice whistling sound that lets you know power is on tap.

I think this leans to the turbo being messed up. I wonder if the turbine is bound or somehow restricted or the wheels are screwed up. What has Minnam to say about this?

Do you have an upgraded clutch? My friend in an eclipse turbo tried to up his boost but no matter how high he turned it it would not go up more that a few pounds over stock. The problem was that the clutch was slipping, and placing less load on the engine. For example... can you get any boost from your turbo when the cat in in neutral, and you nail the gas? I didnt think so. Get a new clutch if you haven't already.

not sure this will help but its worth a shot
http://www.turbofast.com.au/t-shoot.html
tom@kartboy.com

Eureka!!!

I managed to get 7 psi by using that trick Michael/SkiDaZZLe and Mike Jerry suggested. I plugged the boost hose to the wastegate with a golf tee and had it up to 7 psi (or so) in no time. I wish I had just shipped that damn wastegate back to Turbonetics in the first place, but I think vacuum leaks/ other leaks made more sense. Oh well...

Regarding some of the other recent suggestions:
Mike- I've never been in even a close call with a curb or other object in the Sube. I would have been shocked if there was some hidden exhasut restriction.
Tom- That link seems pretty good. I'm just even MORE glad I don't need it just yet. http://www.i-club.com/ubb-files/wink.gif
Dr. Zaeus- I installed a new ACT clutch at the same time the turbo went in. Once I get it all back together, I *shouldn't* have any trouble getting power down.

Thanks to ALL!
I'll post to this thread once more when I have my baby back together and running (perfectly) again.
-Scott

BTW- I haven't bothered calling Minnam in a while on this one. They've had the same suggestions as you guys all along. http://www.i-club.com/ubb-files/smile.gif Why waste my time and "theirs?" LOL

Awesome news Molez... I'm curious now to know, what is your total outlay so far? Did you buy the RS new?

I'm still travelling extensively, so I'm a long time away from purchasing a Sube, but it'd be nice to know what kind of outlay I can expect. Of course, if I stick with this contract, I will be in the market at just about the time that the factory turbocharged Impreza's are supposed to be released.

Ahhhhhh, I'm STILL only getting 3 psi. Alright, what gives.
Turbonetics said the wastegate seemed to be working fine. They rebulit it anyway. I just finished installing it and there's been no change. Obviously I'm missing some sort of easy solution at this point since it will spool past 3 psi if I plug that hose from the turbo to the wastegate.
-So is there supposed to be a hose attached to the "vacuum" nipple on the top of the wastegate? If so, to what?
-Should the vacuum outlet not even have the nipple screwed in/ attached to it?
-Should the hose from the turbo feed into the vacuum nipple instead of the "boost" one?
-Some other possibilty?

Can someone help a bumbling idiot see the answer that is apparently right in front of his nose. http://www.i-club.com/ubb-files/wink.gif
Thx!
-Scott

[This message has been edited by Molez93 (edited June 10, 2000).]

What are you using for a boost controller? Are you using a boost controller? What is the wastegate set at(in terms of psi)? Have you tried setting the wastegate to a higher setting? Like if you trying 5psi, try doing like 7psi and see if there is a difference. Also, are you sure the boost gauge is accurate? Is it mechanical? There might be a leak there somewhere, but that would probably not cause your problem.

Chris
92 Stealth Twin Turbo (AWD)

[This message has been edited by OrdinaryStealthTurbo (edited June 10, 2000).]