Welcome to the North American Subaru Impreza Owners Club Friday August 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 > Engine Management & Tuning > AccessPort

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 05-12-2012, 09:03 PM   #1
moonrider_99
Scooby Specialist
 
Member#: 258628
Join Date: Sep 2010
Chapter/Region: Tri-State
Location: PA
Vehicle:
2009 WRX stg2-SOLD
2012 MS3

Default 2009 WRX Stage 2 + SF (light knock?)

Greetings Nasioc,

I think I'm getting some knock at higher rpm with my new setup, I would greatly appreciate if COBB could comment on these logs. Thank you.

2009 WRX Stage 2 + SF map 93 Octaone, version 3.0, normal wastegate.
Running the MadDad shorty + COBB SF intake. 75F temperature. 93 Octane.

Thanks!

https://docs.google.com/spreadsheet/...VNvelNpRURJTmc

https://docs.google.com/spreadsheet/...0ctQ3BXbzlvZnc

https://docs.google.com/spreadsheet/...Ec2bTdLZGlmd0E
* Registered users of the site do not see these ads.

Last edited by moonrider_99; 05-12-2012 at 09:09 PM.
moonrider_99 is offline   Reply With Quote
Old 05-13-2012, 08:15 AM   #2
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by moonrider_99 View Post
Greetings Nasioc,

I think I'm getting some knock at higher rpm with my new setup, I would greatly appreciate if COBB could comment on these logs. Thank you.

2009 WRX Stage 2 + SF map 93 Octaone, version 3.0, normal wastegate.
Running the MadDad shorty + COBB SF intake. 75F temperature. 93 Octane.

Thanks!

https://docs.google.com/spreadsheet/...VNvelNpRURJTmc

https://docs.google.com/spreadsheet/...0ctQ3BXbzlvZnc

https://docs.google.com/spreadsheet/...Ec2bTdLZGlmd0E
One of your long-term fuel trims (A/F Learning 1) is borderline extreme (-6.25%). You may have a boost leak. I would recommend getting a pressure or smoke test of the intake tract done. There are some DIY threads about pressure testing for those that have air compressors at home.

Some high load fine knock learning can be due to abruptly lifting off the throttle at the end of a WOT run. This is then re-applied over and over (well after the event) until the ECU learns the correction back to zero. Usually, though, that is a single count (i.e. -1.4 in this case).

You can reflash our most conservative map (ACN91) until you get the pressure test done.

Bill
Cobb Tuning is offline   Reply With Quote
Old 05-13-2012, 09:57 AM   #3
moonrider_99
Scooby Specialist
 
Member#: 258628
Join Date: Sep 2010
Chapter/Region: Tri-State
Location: PA
Vehicle:
2009 WRX stg2-SOLD
2012 MS3

Default

Quote:
Originally Posted by Cobb Tuning View Post
One of your long-term fuel trims (A/F Learning 1) is borderline extreme (-6.25%). You may have a boost leak. I would recommend getting a pressure or smoke test of the intake tract done. There are some DIY threads about pressure testing for those that have air compressors at home.

Some high load fine knock learning can be due to abruptly lifting off the throttle at the end of a WOT run. This is then re-applied over and over (well after the event) until the ECU learns the correction back to zero. Usually, though, that is a single count (i.e. -1.4 in this case).

You can reflash our most conservative map (ACN91) until you get the pressure test done.

Bill
Hi Bill, thank you for your quick reply.

I have a few questions. Regarding the possible boost leak and A/F learning 1 correction, this means my car is going lean (unmetered air after MAF, before Turbo) and the ECU is adding fuel to compensate-correct? How is A/F learning 1 calculated? Since the final A/F ratio is in the 11s, is it safe to say that for the time being, the car is running "fine"...?

I have a log from 2/08/2012 when I was STAGE 1 + SF (stock dp), my A/F Learning 1 values were the same.
https://docs.google.com/spreadsheet/...1E4VGZ0R2lkSnc


Interestingly, same STAGE 1 + SF setup but logged on 6/15/2011. Does this mean I could have an air leak in my COBB intake?
https://spreadsheets.google.com/spre...IzYkE&hl=en_US


I'm going to get the car tested for leaks in the next 7-10 days, provided I drive conservatively for now, how urgent is getting this resolved?

Is the knocking related to the possible boost leak or are these two separate things? Should I consider getting a Pro-tune?

Thank you

Last edited by moonrider_99; 05-13-2012 at 11:08 AM.
moonrider_99 is offline   Reply With Quote
Old 05-13-2012, 11:13 AM   #4
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by moonrider_99 View Post
Hi Bill, thank you for your quick reply.

I have a few questions. Regarding the boost leak, is this resulting in my car going lean or too rich? How is A/F learning 1 one calculated? And how come I hit peak boost if there's a leak?

I'm going to get the car tested in the next 7-10 days, provided I drive conservatively for now, how urgent is getting this resolved?

Is the knocking related to the possible boost leak or are these two separate things? Should I consider getting a Pro-tune?

Thank you
With a boost leak, you would be losing metered air, causing you to go rich, and causing your fuel trims to be negative (i.e. pull fuel because you are rich). No guarantee that you have a boost leak though - that one fuel trim range was only borderline extreme - could be nothing. Keep your eye on the trims over time before your tune (you can check all 4 ranges by looking at the A/F Learning 1 A, B, C, D values via live data).

You can still hit peak boost with a boost leak because the ECU can compensate for the loss of boost and ramp up wastegate duty. A boost leak can cause problems depending on its severity because the turbo ends up producing more boost than you are actually seeing in the logs (possibly putting it outside its efficiency range). That means hotter intake air and greater chance of detonation. Again, that may not be the case here, but when you have any suspicion about it, it would be a good idea to get a pressure test done. Especially before you get your tune. There isn't a problem with driving it until then - just keep an eye on the fuel trims. If they start to get even worse, that may be a clue that a fueling issue is more of a possibility.

Bill
Cobb Tuning is offline   Reply With Quote
Old 05-13-2012, 11:46 AM   #5
moonrider_99
Scooby Specialist
 
Member#: 258628
Join Date: Sep 2010
Chapter/Region: Tri-State
Location: PA
Vehicle:
2009 WRX stg2-SOLD
2012 MS3

Default

Quote:
Originally Posted by Cobb Tuning View Post
With a boost leak, you would be losing metered air, causing you to go rich, and causing your fuel trims to be negative (i.e. pull fuel because you are rich). No guarantee that you have a boost leak though - that one fuel trim range was only borderline extreme - could be nothing. Keep your eye on the trims over time before your tune (you can check all 4 ranges by looking at the A/F Learning 1 A, B, C, D values via live data).

You can still hit peak boost with a boost leak because the ECU can compensate for the loss of boost and ramp up wastegate duty. A boost leak can cause problems depending on its severity because the turbo ends up producing more boost than you are actually seeing in the logs (possibly putting it outside its efficiency range). That means hotter intake air and greater chance of detonation. Again, that may not be the case here, but when you have any suspicion about it, it would be a good idea to get a pressure test done. Especially before you get your tune. There isn't a problem with driving it until then - just keep an eye on the fuel trims. If they start to get even worse, that may be a clue that a fueling issue is more of a possibility.

Bill
Thanks you for the follow up Bill, I have difficulty getting responses on the COBB forum but on Nasioc I certainly can't complain, I really appreciate getting two responses on a Sunday.

My fuel trims are "-", I'm sorry I thought it was "+" for some reason and was adding fuel. Since it's negative, ECU is removing fuel because a portion of the metered air may be escaping, suggesting (in theory) a post turbo leak- i got it now.

I will have the car checked, I'm just curious what happened between June of last year and February of 2012. The A/F correction went from -2.34 to -6.25 and that was without any mechanical changes. Then, with the addition of a shorty DP, it stayed at -6.25.

Last edited by moonrider_99; 05-13-2012 at 11:51 AM.
moonrider_99 is offline   Reply With Quote
Old 05-13-2012, 07:12 PM   #6
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by moonrider_99 View Post
Thanks you for the follow up Bill, I have difficulty getting responses on the COBB forum but on Nasioc I certainly can't complain, I really appreciate getting two responses on a Sunday.

My fuel trims are "-", I'm sorry I thought it was "+" for some reason and was adding fuel. Since it's negative, ECU is removing fuel because a portion of the metered air may be escaping, suggesting (in theory) a post turbo leak- i got it now.

I will have the car checked, I'm just curious what happened between June of last year and February of 2012. The A/F correction went from -2.34 to -6.25 and that was without any mechanical changes. Then, with the addition of a shorty DP, it stayed at -6.25.
The long-term fuel trims can fluctuate over time, but generally they should be within +/- 5%. Intake tract leaks are not uncommon. Sometimes they can occur without reason and sometimes due to removal of, for example, the intercooler, you can introduce a leak (bpv is common area).

Bill
Cobb Tuning is offline   Reply With Quote
Old 06-16-2012, 08:07 AM   #7
moonrider_99
Scooby Specialist
 
Member#: 258628
Join Date: Sep 2010
Chapter/Region: Tri-State
Location: PA
Vehicle:
2009 WRX stg2-SOLD
2012 MS3

Default

Cobb,

I think your boost leak diagnosis was correct, what was a minor leak became more significant.

Yesterday my car developed a loud boost leak. I’m going to take a guess and first change my OEM BPV myself and see if that helps.

Is the car is safe to drive (off boost of course), based on this short log? It looks like I have a major leak after the turbo as A/F Learning 1 (%) values are “-“. And I don’t hit full boost (should be 18.5-19 PSI) but my A/F is ok and I see no knock.

https://docs.google.com/spreadsheet/...WhSSUNFQ3RlQmc


Thanks
moonrider_99 is offline   Reply With Quote
Old 06-16-2012, 08:06 PM   #8
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by moonrider_99 View Post
Cobb,

I think your boost leak diagnosis was correct, what was a minor leak became more significant.

Yesterday my car developed a loud boost leak. Iím going to take a guess and first change my OEM BPV myself and see if that helps.

Is the car is safe to drive (off boost of course), based on this short log? It looks like I have a major leak after the turbo as A/F Learning 1 (%) values are ď-ď. And I donít hit full boost (should be 18.5-19 PSI) but my A/F is ok and I see no knock.

https://docs.google.com/spreadsheet/...WhSSUNFQ3RlQmc


Thanks
I wouldn't do any heavy throttle runs with a known fueling-related issue until you get it fixed. But you are OK in this case to drive it around conservatively.

Bill
Cobb Tuning is offline   Reply With Quote
Old 06-17-2012, 06:35 PM   #9
moonrider_99
Scooby Specialist
 
Member#: 258628
Join Date: Sep 2010
Chapter/Region: Tri-State
Location: PA
Vehicle:
2009 WRX stg2-SOLD
2012 MS3

Default

Quote:
Originally Posted by Cobb Tuning View Post
I wouldn't do any heavy throttle runs with a known fueling-related issue until you get it fixed. But you are OK in this case to drive it around conservatively.

Bill
Thank you, BPV on order and appointment for next weekend with a local Subaru shop just in case. I'll report the outcome for historical purposes.
moonrider_99 is offline   Reply With Quote
Old 10-06-2012, 11:29 PM   #10
moonrider_99
Scooby Specialist
 
Member#: 258628
Join Date: Sep 2010
Chapter/Region: Tri-State
Location: PA
Vehicle:
2009 WRX stg2-SOLD
2012 MS3

Default

Bump for COBB.

Bill was 100% correct regarding the air leak and resulting ECU correction that he noticed in my logs. The car was smoke tested and I had a leak on the left side of the intercooler where it is connected to the turbo, so I was loosing metered air under boost.
Thank you for pointing this out and I'm very impressed with the accurate diagnosis by Bill/COBB just by looking at my logs.

Last edited by moonrider_99; 10-07-2012 at 10:48 AM.
moonrider_99 is offline   Reply With Quote
Old 10-07-2012, 09:41 AM   #11
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by moonrider_99 View Post
Bump for COBB.

Bill was 100% correct regarding the air leak and resulting ECU correction that he noticed in my logs. The car was smoke tested and I had a leak on the left side of the intercooler where it is connected to the turbo, so I was loosing metered air under boost.
Thank you for point this out and I'm very impressed with the accurate diagnosis by Bill/COBB just by looking at my logs.
Glad you got it sorted. Really could have been any number of things, but post-MAF intake leaks are the easiest to verify and fix, so it is the best thing to look at first.

Bill
Cobb Tuning 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
2002 WRX Stage 2 Datalog, fine knock and boost spike problems SedonaRedwagon AccessPort 9 01-11-2012 02:38 PM
2009 wrx stage 2 dyno numbers BigSteiner5 Proven Power Bragging 30 10-15-2009 08:04 PM
2009 WRX Stage 2 JoeyOKC Proven Power Bragging 10 09-25-2009 10:45 AM
2009 WRX Stage 2 tune JoeyOKC Open Source Reflashes 25 09-20-2009 07:39 PM
? for 2009 WRX stage 2, fueling yamie700 Factory 2.5L Turbo Powertrain 7 02-11-2009 08:04 AM


All times are GMT -4. The time now is 06:49 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.