Welcome to the North American Subaru Impreza Owners Club Tuesday July 29, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 01-02-2007, 04:53 PM   #1
theostubbs
Scooby Newbie
 
Member#: 122286
Join Date: Aug 2006
Chapter/Region: W. Canada
Vehicle:
2007 STi

Default BCS Bypass, opinions please?

Having oscillating boost on my Wrex. Most people seem to call it as boost surging.

Reference post:

http://forums.nasioc.com/forums/show...ighlight=surge

I'd like to try bypassing the Boost Control Solenoid to see if it stops the boost oscillations before i order the new part. I'd probably just plug off the BCS hose right at the T. My question is..

What boost levels can i expect (stock WG actuator and spring), and will this be acceptable to run for a few weeks while parts are ordered? I dont mind running low boost for a few weeks as long as it wont hurt nothing. If i'm not mistaken, the car will still run the 9-10 Air/Fuel ratio and ignition timing just as if it had boost, it just wont make the power?

thanks guys!
* Registered users of the site do not see these ads.
theostubbs is offline   Reply With Quote
Old 01-02-2007, 05:20 PM   #2
Jasper
Scooby Specialist
 
Member#: 80136
Join Date: Jan 2005
Chapter/Region: NESIC
Location: Saugus, MA
Vehicle:
2006 Ford F-150
Black

Default

borrow a stock BCS. im sure at least one or two locals have one (i have a spare one sitting in my toolbox).


mod list?
Jasper is offline   Reply With Quote
Old 01-02-2007, 05:28 PM   #3
theostubbs
Scooby Newbie
 
Member#: 122286
Join Date: Aug 2006
Chapter/Region: W. Canada
Vehicle:
2007 STi

Default

Cobb Stage 2 equivalent, Helix up, cobb down,
theostubbs is offline   Reply With Quote
Old 01-02-2007, 05:35 PM   #4
Jasper
Scooby Specialist
 
Member#: 80136
Join Date: Jan 2005
Chapter/Region: NESIC
Location: Saugus, MA
Vehicle:
2006 Ford F-150
Black

Default

EM?

too much WG duty cycle can cause surging/oscillating boost. (i ran into this when i was tuning my stock-turbo setup, would surge between 16-18psi and was VERY pronounced while driving.
Jasper is offline   Reply With Quote
Old 01-02-2007, 06:25 PM   #5
wrxdrvr
Scooby Specialist
 
Member#: 79222
Join Date: Jan 2005
Chapter/Region: W. Canada
Location: Canada BC
Vehicle:
'09 STi 297.5 WHP
Blue

Default

You can run it like that for the test but I would just stay off full boost until you get the FBC solenoid cleaned/fixed or get a new one. You should get around 7-8 PSi boost with the line pluged off.
wrxdrvr is offline   Reply With Quote
Old 01-03-2007, 10:56 AM   #6
theostubbs
Scooby Newbie
 
Member#: 122286
Join Date: Aug 2006
Chapter/Region: W. Canada
Vehicle:
2007 STi

Default

great thanx for the help guys.

Yes definately looking at my EM. Going back to a stock rom for troubleshooting as soon as i can secure a laptop (mine's broken).
theostubbs is offline   Reply With Quote
Old 01-03-2007, 12:00 PM   #7
tachrev
Scooby Newbie
 
Member#: 115260
Join Date: May 2006
Chapter/Region: MAIC
Location: Dover, DE
Vehicle:
04 WRX
205/22E Hybrid w/ VF39

Default

Quote:
Originally Posted by wrxdrvr View Post
You can run it like that for the test but I would just stay off full boost until you get the FBC solenoid cleaned/fixed or get a new one. You should get around 7-8 PSi boost with the line pluged off.
There is no reason why you can't run around with the BCS unhooked and hit full wastegate boost(7-8psi, as stated) as much as you want.
It won't hurt it a bit more than hitting full boost with it plugged in at ~16psi.
Less, even.
Consider it a "low boost map".
The stock ecu will just be using lower load cells, it will handle it fine.
If that's what you need to do, then go for it.
I am doing it right now becuase my clutch started letting go when I hit full boost.
I just unplugged the wires to the BCS and ignore the check engine light.
I'm hoping I can make it through the winter on wastgate boost.
tachrev is offline   Reply With Quote
Old 01-03-2007, 12:08 PM   #8
scooby1220
Scooby Newbie
 
Member#: 125129
Join Date: Sep 2006
Chapter/Region: Tri-State
Location: NY
Vehicle:
2004 WRX VF34'd
Silver

Default

I would reccommend taking the restrictor pill out of the compressor side line instead of unplugging the BCS. Doing it this way will still run wastegate boost (about 8psi at most) and you wont have a CEL.
scooby1220 is offline   Reply With Quote
Old 01-03-2007, 12:41 PM   #9
theostubbs
Scooby Newbie
 
Member#: 122286
Join Date: Aug 2006
Chapter/Region: W. Canada
Vehicle:
2007 STi

Default

excellent
theostubbs is offline   Reply With Quote
Old 01-03-2007, 12:43 PM   #10
tachrev
Scooby Newbie
 
Member#: 115260
Join Date: May 2006
Chapter/Region: MAIC
Location: Dover, DE
Vehicle:
04 WRX
205/22E Hybrid w/ VF39

Default

The only way to run wastegate boost is if the only thing controlling the boost is the wastegate.
You can do this by unplugging the wires to the BCS(check engine light), or unhooking and plugging the vacuum line to the BCS(no check engine light).
Taking out the pill will make the boost lower, but if the bcs is the problem, it will continue to be a problem because it will still be bleeding off wastegate signal.
tachrev is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
06 wrx 6speed vf39 gs bcs datalog review please help?? wrxcbr6rr Open Source Reflashes 9 11-03-2009 03:46 PM
Anyone local know UTEC pretty well? GM BCS help needed PLEASE!! lol Wrx_Fan_0717 Mid Atlantic Impreza Club -- MAIC 7 08-03-2007 07:36 PM
Who knows UTEC pretty well? GM BCS help needed PLEASE!! lol Wrx_Fan_0717 UTEC 4 08-03-2007 05:41 PM
Components -- opinions please SilverSuby Car Audio, Video & Security 21 06-13-2001 06:34 AM
what price is forseen on purchase of a WRX at the end of the year....opinions please? joostin420 New England Impreza Club Forum -- NESIC 5 04-13-2001 08:50 PM


All times are GMT -4. The time now is 07:19 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.