Welcome to the North American Subaru Impreza Owners Club Wednesday August 23, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

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. 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 11-14-2012, 04:53 AM   #1
Scooby Newbie
Member#: 333798
Join Date: Sep 2012
Chapter/Region: BAIC
Location: Bay Area, CA
2005 WRX

Question Underboost/fluctuating boost (datalogs incl.)

Hey guys,

So first of all I have an 05 WRX with the following:
-Invidia V2 catless DP
-HKS midpipe/flowmaster axelback
-Catless UP (from 06 WRX)
-Cobb AP flashed to stage 2 ACN91
-Large ebay intercooler
-Cosworth high flow air filter in otherwise stock intake

According to AP monitors boost levels are significantly under target; at idle boost hovers around -8 (target is -1) and is usually 3 psi + under target at highway speeds. Under acceleration it's not as significant but still outside the ideal range. The following datalog shows a pull in 3rd gear:


I've also had an intermittent problem where the boost will fluctuate under throttle. For whatever reason the above datalog was during a period when the car decided not to have the issue I only have a datalog of the fluctuating boost from when the car was stage 1 but I think it will show necessary info. The following is in 4th gear under moderate throttle:


I've had a boost leak test done and nothing was found, but since the fluctuating boost is intermittent I can't say for sure that that's not the problem...

I know I could use a HWG map to counter underboosting but I want to know what's causing it. I was expecting to have to use a LWG map to counter boost creep from the catless DP!

So... what's causing these problems? Could they be related? Any help is appreciated

Last edited by WRBlueJ; 11-21-2012 at 12:25 AM.
WRBlueJ is offline   Reply With Quote

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

All times are GMT -4. The time now is 03:48 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.