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Discussion Starter · #1 ·
Hi, I just bought a wrx 09 last week, I drive the car 3 time, everythind was good until today, it is overboost.

mods
vf39turbo
sti injector
sti intake
up pipe cobb
down pipe with hf cat
invidia exhaust twin exist with muffler
piston and rods manley (dont know the spec)
stud arp
crank and rod bearing from acl
boost tee
block off plate
inlet perrin


I was boosting 17 psi and now it reach 25, it scare me(dont want a blowup my car), I had 2 code that I erease 0108 and p0244.

Even if I lower the boost ( my manuel boostcontroler, it does nothing still over boosting. and my stock bov sound like a ssqv.(wasnt sound like that before)

Iam not sure how I can data log?

also I read a lot and it see like I need more backpressure or externalwestgate , or a ported?but my question is why its start overboosting?
 

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Discussion Starter · #4 ·
I guess, it look like I have a custom map,
my boost target is 19 psi, last owner lower it to 17,but the wrx boosting to much and I didnt change anything.
The temperature is cold right btw.
any idea where to start my research, dont want to go ewg now
can my iwg is stock close?
or maybe I can check hoses o somthing?
 

· For External Use Only
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3,884 Posts
Take it to your local tuner. Sounds like it needs retuned anyway, and they can also help you troubleshoot.
 

· Not a mod... or is he? Or, is he not?
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I may be mistaken but you can't just fiddle with your boost controller at random with out a tune

Sent from my SAMSUNG-SM-G935A using Tapatalk
 

· Not a mod... or is he? Or, is he not?
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I'm not a data log pro, I wish I could help you there. Over boosting occurs because the wastegate can't bleed off enough air to keep the pressure where it should be. It can be mechanical, or a bad tune.

I may be completely wrong, but in my understanding the system is tuned with a certain air flow and changes to that airflow that the ecu doesn't see can cause issues with proper wastegate function. I may be completely wrong, but my first suspect would be a bad manual boost controller or bad tune.

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"I was just playing with it and it does nothing"...... You're going to blow your car up. Stop messing with it. Take your car to a tuner.
 

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Discussion Starter · #16 ·
"I was just playing with it and it does nothing"...... You're going to blow your car up. Stop messing with it. Take your car to a tuner.
why am I going to blow up my car? Its not dangerous to lower the boost and after replace it where its was....

I wanna fix my overboost, after that I ll get a tune if need it, nobody know how westgate duty cycle work?
 

· Not a mod... or is he? Or, is he not?
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15,792 Posts
why am I going to blow up my car? Its not dangerous to lower the boost and after replace it where its was....

I wanna fix my overboost, after that I ll get a tune if need it, nobody know how westgate duty cycle work?
From what I understand fueling tables are dialed in for certain boost at a particular rpm. When you fiddle with the boost controller you are messing with that fuel table and it can go kabang.

Boost isn't something you screw around with every day.

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If you have only a Manual boost controller than the tune can't be bad, as the computer would have no effect on wastegate duty cycles.

My best guess is that one of the boost hoses in the turbo--MBC--Wastegate junction has fallen off.
If you have no pressure to open the wastegate, you get overboost.
 

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Discussion Starter · #19 ·
If you have only a Manual boost controller than the tune can't be bad, as the computer would have no effect on wastegate duty cycles.

My best guess is that one of the boost hoses in the turbo--MBC--Wastegate junction has fallen off.
If you have no pressure to open the wastegate, you get overboost.
I see somthing the lenght of th hose may have an impact on the wastegate oppening? am i right

thx for the advice I will try send u picture if u dont mind?
 

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The length should only have a minor effect, you really wouldn't notice it unless they were excessively long.
Also because you didn't make any changes between when it worked and when it didn't, the solution that makes the most sense is that something just fell off or broke. Check the lines for dry rot and cracks as well when you are under there.

Feel free to send pictures and I will help as I can
 
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