Over boosting need help
Thread Starter
Joined: Jul 2006
Posts: 1,071
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From: Vancouver, WA
Over boosting need help
Hey guys I've been trying to solve my over boost issue.
Car is stock aside from a pfc, double throttle and egr delete. Dp with highflow cat. Stock sequential twins(which function properly, transition at 4500 and both come online)
I am out of ideas, I have tested pretty much everything. The car is running 1 bar+.
I have swapped the boost solenoid, wastegate actuator, verified the wastegate opens with air. I unplugged the vacuum line to the boost solenoid and plugged it effectively making the car run off wastegate, still the same issue but it appears to not boost as much(was hitting 1.2+before and seemed to not go above 1.04 bar).
The way I understand the turbo system is that only one solenoid/actuator/wastegate controls the boost. When I removed the actuator I verified the wastegate moved freely.
Any ideas or insight I am at a wall with this issue.
Thanks,
Chance
Car is stock aside from a pfc, double throttle and egr delete. Dp with highflow cat. Stock sequential twins(which function properly, transition at 4500 and both come online)
I am out of ideas, I have tested pretty much everything. The car is running 1 bar+.
I have swapped the boost solenoid, wastegate actuator, verified the wastegate opens with air. I unplugged the vacuum line to the boost solenoid and plugged it effectively making the car run off wastegate, still the same issue but it appears to not boost as much(was hitting 1.2+before and seemed to not go above 1.04 bar).
The way I understand the turbo system is that only one solenoid/actuator/wastegate controls the boost. When I removed the actuator I verified the wastegate moved freely.
Any ideas or insight I am at a wall with this issue.
Thanks,
Chance
Rotary Enthusiast
Joined: Apr 2008
Posts: 1,092
Likes: 5
From: NZ
The wastegate is only controlled by pressure that goes to the wastegate actuator.
The pressure that goes to the wastegate actuator is determined by a restriction in the wastegate actuator line. A pill in the hose on older models, or restriction built into the nipple on the turbos on the newer turbos.
Anyway, what you should do is remove the restriction in the wastegate line, by either removing the pill in the hose, or drilling out the restriction in the nipple on the turbos. (depding on which ones you have)
This will allow your wastegate to run off spring pressure, which is about 7 or 8 psi of boost. That's the theoretical minimum boost you can run. If you still make too much boost then you need to port the wastegate.
If all is fine, you can install a needle valve or manual boost controller onto the actuator line to the wastegate so you can fine tune the restriction to the wastegate so it runs just under the level where you experience problems.
Your flow mods will be making it flow to much so your wastegate cant react quick enough. You need to remove the restriction so the wastegate can react faster and dump exhaust easier.
If you have boost creep with no restriction to the wastegate you need to port your wastegate.
The pressure that goes to the wastegate actuator is determined by a restriction in the wastegate actuator line. A pill in the hose on older models, or restriction built into the nipple on the turbos on the newer turbos.
Anyway, what you should do is remove the restriction in the wastegate line, by either removing the pill in the hose, or drilling out the restriction in the nipple on the turbos. (depding on which ones you have)
This will allow your wastegate to run off spring pressure, which is about 7 or 8 psi of boost. That's the theoretical minimum boost you can run. If you still make too much boost then you need to port the wastegate.
If all is fine, you can install a needle valve or manual boost controller onto the actuator line to the wastegate so you can fine tune the restriction to the wastegate so it runs just under the level where you experience problems.
Your flow mods will be making it flow to much so your wastegate cant react quick enough. You need to remove the restriction so the wastegate can react faster and dump exhaust easier.
If you have boost creep with no restriction to the wastegate you need to port your wastegate.
Last edited by 96fd3s; Jan 15, 2015 at 05:41 PM.
The wastegate is only controlled by pressure that goes to the wastegate actuator.
The pressure that goes to the wastegate actuator is determined by a restriction in the wastegate actuator line. A pill in the hose on older models, or restriction built into the nipple on the turbos on the newer turbos.
Anyway, what you should do is remove the restriction in the wastegate line, by either removing the pill in the hose, or drilling out the restriction in the nipple on the turbos. (depding on which ones you have)
This will allow your wastegate to run off spring pressure, which is about 7 or 8 psi of boost. That's the theoretical minimum boost you can run. If you still make too much boost then you need to port the wastegate.
If all is fine, you can install a needle valve or manual boost controller onto the actuator line to the wastegate so you can fine tune the restriction to the wastegate so it runs just under the level where you experience problems.
Your flow mods will be making it flow to much so your wastegate cant react quick enough. You need to remove the restriction so the wastegate can react faster and dump exhaust easier.
If you have boost creep with no restriction to the wastegate you need to port your wastegate.
The pressure that goes to the wastegate actuator is determined by a restriction in the wastegate actuator line. A pill in the hose on older models, or restriction built into the nipple on the turbos on the newer turbos.
Anyway, what you should do is remove the restriction in the wastegate line, by either removing the pill in the hose, or drilling out the restriction in the nipple on the turbos. (depding on which ones you have)
This will allow your wastegate to run off spring pressure, which is about 7 or 8 psi of boost. That's the theoretical minimum boost you can run. If you still make too much boost then you need to port the wastegate.
If all is fine, you can install a needle valve or manual boost controller onto the actuator line to the wastegate so you can fine tune the restriction to the wastegate so it runs just under the level where you experience problems.
Your flow mods will be making it flow to much so your wastegate cant react quick enough. You need to remove the restriction so the wastegate can react faster and dump exhaust easier.
If you have boost creep with no restriction to the wastegate you need to port your wastegate.
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