Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L 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.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 04-04-2010, 01:09 AM   #1
BrianMR2
Scooby Newbie
 
Member#: 238679
Join Date: Feb 2010
Location: Longmont, Colorado
Vehicle:
2007 WRX TR
WRB

Default Not hitting peak boost with Accessport V2 and extreme taper.

I have been having trouble hitting peak boost with my WRX, it's a 2007 2.5 and Cobb says peak boost should be around 15 PSI with 91 Octane and taper to around 10 PSI. I have not been getting quite that, I have been getting a highest peak of around 13.5 and Tapering to around 7-8 PSI. It seems to be holding stable around 12 PSI which seems low. I am at High Altitude (Colorado) so this may play a factor but a buddy of mine with an 02 WRX hits just above peak up here. I have been noticing a light noise if I floor it at about 2-2.5k of a fluttering noise (sounds very much like a exhaust leak or as if the wastegate is fluttering). I have tried adjusting the wastegate arm several times and each time I saw no difference whatsoever in boost or stability of boost. I have posted a datalog hoping someone would have a similar one to compare, of if you could tell me if you see anything strange that might be causing the issue. I know online diags are hard but unfortunatly I have to buy license plates this month and do not have the extra money to see a subaru specialist at the moment.
Mods :
Cobb Bellmouth DP
HKS Carbon TI Catback
Accessport V2 running Stage 2 91 Oct Map
Forge Blow Off Valve non recirc.

Appriciate any insight on this issue.

Brian Melton

Datalog in Excel format :
http://www.brianmelton-pc.com/DatalogBoost.xls
* Registered users of the site do not see these ads.
BrianMR2 is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 04-04-2010, 01:17 AM   #2
BrianMR2
Scooby Newbie
 
Member#: 238679
Join Date: Feb 2010
Location: Longmont, Colorado
Vehicle:
2007 WRX TR
WRB

Default

Additional information : The run was a 2nd Gear pull also have a 3rd Gear Pull Datalog of same peak boost level.
BrianMR2 is offline   Reply With Quote
Old 04-04-2010, 12:01 PM   #3
arghx7
Scooby Specialist
 
Member#: 232940
Join Date: Dec 2009
Location: cold
Default

pressure test for boost leaks
arghx7 is offline   Reply With Quote
Old 04-04-2010, 01:41 PM   #4
BrianMR2
Scooby Newbie
 
Member#: 238679
Join Date: Feb 2010
Location: Longmont, Colorado
Vehicle:
2007 WRX TR
WRB

Default

40 Views 1 reply, anyone have a datalog of a 2nd or 3rd gear pull of a 06-07 stage 2 wrx I could at least compare with?
BrianMR2 is offline   Reply With Quote
Old 04-04-2010, 01:57 PM   #5
Uncle Scotty
*** Banned ***
 
Member#: 16200
Join Date: Mar 2002
Vehicle:
OK buy Nates beans
westcoastroasting.com

Default

sounds like elevation to me

those cobb numbers arent applicible for cars at 5000 foot altitude

call cobb and ask THEM
Uncle Scotty is offline   Reply With Quote
Old 04-04-2010, 02:19 PM   #6
Erik F
Scooby Newbie
 
Member#: 211961
Join Date: May 2009
Chapter/Region: Tri-State
Location: Upstate NY
Vehicle:
09 WRX
Blue

Default

Yes, altitude and or temp. If you look at your Turbo Dynamics...at least in the middle of the run...you are pretty close to what the ECU is requesting. In the area where the turbo is working best...you never really seem to be more than a PSI off what the computer is asking for. There are compensations in the mapping to lower waste gate duty cycles for intake air temps, altitude, and on the newer cars this even effects the target boost numbers. Looks like you are running ok. If you were to run the same boost as someone at sea level your intercooler would not be able to effectively cool the charge.
Erik F is offline   Reply With Quote
Old 04-04-2010, 03:36 PM   #7
scby rex
Scooby Guru
 
Member#: 104878
Join Date: Jan 2006
Chapter/Region: TXIC
Location: copperas cove
Vehicle:
02 wrxbastardchild
aw, MPS 2.34 breaking in

Default

do you have a exhaust leak pre turbo? Or a leak between the turbo and i/c/?
scby rex is offline   Reply With Quote
Old 04-04-2010, 07:52 PM   #8
BrianMR2
Scooby Newbie
 
Member#: 238679
Join Date: Feb 2010
Location: Longmont, Colorado
Vehicle:
2007 WRX TR
WRB

Default

Quote:
Originally Posted by scby rex View Post
do you have a exhaust leak pre turbo? Or a leak between the turbo and i/c/?
This is what I am trying to figure out, I do start to hear a small fluttering when I hear the turbo about to spool and while under boost, which could deff be either of these options. The noise is not a whistle which is making me want to kind of eliminate the pre-turbo leak, and push more towards a leak between innercooler. I do feel the cars performance is good, but the sound is my biggest concern as it really does sound like an exhaust leak of some kind, the fact that you mentioned the innercooler to turbo portion, that is something I have not checked. Is is plausible to upgrade to an 05 STI Innercooler on an 07 or will it not fit as I have noticed the innercooler size is significantly different from the 02-05 wrx on the 06-07.
BrianMR2 is offline   Reply With Quote
Old 04-04-2010, 11:00 PM   #9
scby rex
Scooby Guru
 
Member#: 104878
Join Date: Jan 2006
Chapter/Region: TXIC
Location: copperas cove
Vehicle:
02 wrxbastardchild
aw, MPS 2.34 breaking in

Default

to find a leak take a hose with the engine running and put it to your ear, then move it around to exhaust joints to hear it leaking.
scby rex 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
HELP turbo sounds weird and not hitting peak boost Adrenalinecrisis Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 2 04-12-2010 05:25 PM
Not Hitting Proper Boost with VF39, Cobb Protune - Recommend a Boost Solenoid? whtlegacy Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 20 06-06-2009 03:38 PM
Not Hitting Target Boost with Uppipe Install dan1587wrx Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo) 8 11-11-2008 10:54 PM
Not hitting peak boost :( eurospek AccessPort 1 08-30-2007 07:38 PM
not hitting peak boost with vf 34 blackrod punishment General Community 9 03-07-2006 09:45 AM

All times are GMT -4. The time now is 09:36 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.