Uncontrollable boost...Mystery of the ages
12-03-2005, 05:25 PM
#1
Uncontrollable boost...Mystery of the ages
Some of you are familiar with my long, somewhat drawn out saga with the Turbonetics kit. With the help of Sharif and CP Racing, my pig-rich AFR has been corrected and I'm now at a nice conservative 11.2-ish:1.
From the day this kit was installed, it has always generated more boost than it should. Here's a brief history.....
With no boost controller installed (i.e. relying on the WG spring alone to regulate boost), the car will push 11 PSI or higher. This seems to be regardless of what tension spring is installed, 5, 7 or 9 PSI.
We installed a boost controller, which of course is useless because a boost controller can't LOWER boost below the wastegate spring pressure.
Today, I replaced the wastegate. Hoping beyond hope that the initial wastegate was faulty. Much to my dismay, I still can generate 11+ PSI of boost regardless of whether the boost controller is off or on and set to any boost level. I have the 5 PSI spring installed in the gate (I put it there myself) and no shims are present.
Does anyone have ANY thoughts as to what this might be? I'm completely out of ideas at this point and with as many times as I've generated 11+ pounds of boost (especially with the colder temps) I'm luck I still have an engine that runs, probably thanks to Sharif's tuning.
This is really getting old. I can't drive my car like I want to because it takes a fraction of a second at about 4000 RPM for the boost to skyrocket.
I've replaced the line from the compressor fitting to the signal port on the WG, so I know that line is good. I know the 5 PSI spring is in the gate because I put it there.
I've run out of ideas.
From the day this kit was installed, it has always generated more boost than it should. Here's a brief history.....
With no boost controller installed (i.e. relying on the WG spring alone to regulate boost), the car will push 11 PSI or higher. This seems to be regardless of what tension spring is installed, 5, 7 or 9 PSI.
We installed a boost controller, which of course is useless because a boost controller can't LOWER boost below the wastegate spring pressure.
Today, I replaced the wastegate. Hoping beyond hope that the initial wastegate was faulty. Much to my dismay, I still can generate 11+ PSI of boost regardless of whether the boost controller is off or on and set to any boost level. I have the 5 PSI spring installed in the gate (I put it there myself) and no shims are present.
Does anyone have ANY thoughts as to what this might be? I'm completely out of ideas at this point and with as many times as I've generated 11+ pounds of boost (especially with the colder temps) I'm luck I still have an engine that runs, probably thanks to Sharif's tuning.
This is really getting old. I can't drive my car like I want to because it takes a fraction of a second at about 4000 RPM for the boost to skyrocket.
I've replaced the line from the compressor fitting to the signal port on the WG, so I know that line is good. I know the 5 PSI spring is in the gate because I put it there.
I've run out of ideas.
12-03-2005, 06:02 PM
#5
Originally Posted by Alberto
Maybe your exhaust is too free flowing? Just to test, have you tried running the stock exhaust and see if it boosts that high? Sorry to hear the new wastegate didnt correct the problem Kelly, hope you get it figured out soon.
12-03-2005, 06:06 PM
#6
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i was having the same problem recently and well did every thing you did and nothing fixed the problem so i decided i was gonna check every last bolt on this kit and it turns out that one of the bolts that connects the waste gate pipe to the down pipe was a couple turns from falling out after tightening that and applying some thread locker and also some rtv sealeant on all the connections where the waste gate is at im building a steady 8.5 psi. hope this helps.
12-03-2005, 06:30 PM
#7
Originally Posted by disturbed2483
i was having the same problem recently and well did every thing you did and nothing fixed the problem so i decided i was gonna check every last bolt on this kit and it turns out that one of the bolts that connects the waste gate pipe to the down pipe was a couple turns from falling out after tightening that and applying some thread locker and also some rtv sealeant on all the connections where the waste gate is at im building a steady 8.5 psi. hope this helps.
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12-03-2005, 07:11 PM
#10
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Originally Posted by kcobean
Can you clarify something for me? When you say "the waste gate pipe to the down pipe", do you mean the dump tube that dumps the overflow back into the exhaust system? I'm just wondering how that would make a difference since some people choose to just eliminate that pipe and vent to atmosphere. I'm certainly going to check it though. Thanks.
12-03-2005, 07:17 PM
#11
Originally Posted by disturbed2483
i know what your talking about as far as people venting the wastegate to atmosphere and them not having problems with boost, i didn't understand either but it fixed my problem because i was building a constant 11psi, but since i fixed that "leak" i never boost above 8.5 psi. maybe there is a reason turbonetics doesn't advise you to vent the waste gate to atmosphere.
12-03-2005, 07:25 PM
#12
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Doesn't the gate just work off the compressor line thats connected to the signal port?
Maybe you can put your boost gauge on a T with that line to see what its reading?
Maybe you can put your boost gauge on a T with that line to see what its reading?
12-03-2005, 07:29 PM
#13
Originally Posted by 35ounces
Doesn't the gate just work off the compressor line thats connected to the signal port?
Maybe you can put your boost gauge on a T with that line to see what its reading?
Maybe you can put your boost gauge on a T with that line to see what its reading?
12-03-2005, 09:34 PM
#15
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have you ruled out gremlins dancing inside of your wastegate? just a thought
no really, i have no useful imput, but i know how frustrating something like this can be ...good luck, i hope you get it resolved soon!
no really, i have no useful imput, but i know how frustrating something like this can be ...good luck, i hope you get it resolved soon!
12-03-2005, 10:02 PM
#16
Kcobean,
1. Where exactly does the line from the wastegate plug in, which part of the piping exactly? You mentioned "compressor housing", so just clarifying. It should be plugged in immediately before the throttle body.
2. Do you have stock cams? Just making sure.
1. Where exactly does the line from the wastegate plug in, which part of the piping exactly? You mentioned "compressor housing", so just clarifying. It should be plugged in immediately before the throttle body.
2. Do you have stock cams? Just making sure.
12-04-2005, 04:36 AM
#17
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man that sucks, but sounds like a small problem. I think its the wastegate spring, even though you fixed it. I'de look again. maybe you got a bad spring. Sounds like a wastegate problem for sure.
12-04-2005, 06:45 AM
#18
GurgenPB: Per the Tnetics install instructions, there is a short line that runs from a nipple on the compressor housing of the turbo directly to the signal port on the WG.
The boost controller solenoid has an "in" and and "out" port. The in line is being fed by a manifold tap and the out line goes to the control (top) port on the WG.
BoOsTedz33TT: The entire WG has been replaced and we've tried multiple different springs in the original gate. The current spring is a 5 PSI spring and I could still boost way over 11 PSI with it installed in a brand new gate. I have some bad luck, but the chances are astronomically small at this point that it's a problem with the gate itself.
The boost controller solenoid has an "in" and and "out" port. The in line is being fed by a manifold tap and the out line goes to the control (top) port on the WG.
BoOsTedz33TT: The entire WG has been replaced and we've tried multiple different springs in the original gate. The current spring is a 5 PSI spring and I could still boost way over 11 PSI with it installed in a brand new gate. I have some bad luck, but the chances are astronomically small at this point that it's a problem with the gate itself.
12-04-2005, 08:20 AM
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Holy crap so the wastegate and BOV are both good. Well the only thing left is the exhaust per our discussion on AIM. Let me see if I can find a stock exhaust for you somewhere local and ship it out. Blue Blrr should have his done by next week and we can see if thats his issue (hes running the same exhaust set up as you and getting the same weirdness)