Fine Tuning with Cobb AP Stage 1 + SF
Page 1 of 2 12 LastLast
Results 1 to 15 of 18

This is a discussion on Fine Tuning with Cobb AP Stage 1 + SF within the Tuning: Electronic Engine Management forums, part of the Tech & Modifying & General Repairs category; Hey guys, I recently installed the Cobb SF intake w/ box in my '12 WRX. I tuned with the AP ...

  1. #1
    Registered User
    Join Date
    Mar 2013
    Posts
    44

    Fine Tuning with Cobb AP Stage 1 + SF

    Hey guys, I recently installed the Cobb SF intake w/ box in my '12 WRX. I tuned with the AP using a Stage1 + SF 91 octane map. I use 92 because it is the only widely available high octane gas in Washington State. The map stated peak boost should be at 16.5 (+/-1psi). I drove it easy for 100 miles then recorded a few 3rd gear pulls. I noticed a consistence over-boost to 17.5psi (within the +1 psi stated by Cobb). I went out driving a few nights ago and noticed a max peak at 17.8 then later a 18.0!

    I decided to try the LWG map and see if it would put me closer to nominal, but i'm still showing logs of 17.5psi

    Should I try the super LWG map? Could this increased boost be a result of using 92 octane with the 91 map? (the map does say for 91 and 92 gas though).

    Thoughts?

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #2
    Master Baiter EJ257's Avatar
    Join Date
    Aug 2007
    Location
    On a stream bank somewhere
    Posts
    19,642
    I Support ClubWRX
    Were these logs done on a flat surface?
    2005 WRX STi (Mods | Virtual Dyno)

    Resident Tuner @ WTF Tuning, LLC

    "Never trust anything that bleeds for a week and lives ..."

    UNYSOC

  4. #3
    Registered User
    Join Date
    Mar 2013
    Posts
    44
    Very flat and straight road that is neither up-hill nor down-hill. upon further "investigation" I only hit up to 17.5 in a 4th gear pull with the LWG map. Should I be happy with this +1 psi only under that one condition or should I try to lower this max to a lower psi?

  5. #4
    Registered User
    Join Date
    Mar 2013
    Posts
    43
    My understanding is your only worried with boost levels in 3rd ger that's the 1:1 gear you want. Any other gear will show something different. Knock would be what I'd be looking at.
    Jeff

  6. #5
    Registered User
    Join Date
    Mar 2013
    Posts
    44
    No knock issues at all. everything looks good except slightly higher boost.

  7. #6
    Registered User
    Join Date
    Apr 2013
    Posts
    14
    What will be the negative effects of higher boost?

  8. #7
    Moderator Donkey's Avatar
    Join Date
    Apr 2005
    Location
    Da boonies
    Posts
    5,966
    I Support ClubWRX
    Quote Originally Posted by 20T-WRX12 View Post
    What will be the negative effects of higher boost?
    A blown motor....
    Resident Adviser @ WTF Tuning, LLC
    2002 FORESTER S
    1998 FORESTER S




  9. #8
    Registered User
    Join Date
    Mar 2013
    Posts
    44
    Okay, i've done quite a lot of logging over the past two weeks. I'm showing consistent boost near 16.5psi or under except for some 4th gear pulls still registering up to 17.4psi, but usually ~17.1psi

    I feel a lot more comfortable now that the max boost is within the +/-1 psi that Cobb states, but should I still be worried about the over-boost even when its within Cobb's tolerance and only in occasional 4th gear pulls?

  10. #9
    and the Funky Bunch Calvinball's Avatar
    Join Date
    Jan 2012
    Location
    Philly Area
    Posts
    5,920
    Quote Originally Posted by Desolatemm View Post
    Okay, i've done quite a lot of logging over the past two weeks. I'm showing consistent boost near 16.5psi or under except for some 4th gear pulls still registering up to 17.4psi, but usually ~17.1psi

    I feel a lot more comfortable now that the max boost is within the +/-1 psi that Cobb states, but should I still be worried about the over-boost even when its within Cobb's tolerance and only in occasional 4th gear pulls?
    I'm no Donkey, but I believe it is normal for the boost to be higher in 4th gear than it is in third.
    - Will
    First Mods: What to do and what not to do
    Current Car: 2014 Golf TDI
    Previous Cars:2012 WRB WRX Hatch, 2004 RSX-S, 1998 Grand Prix GTP
    "Isn't it amazing how smart you feel when you just aren't being stupid?"

  11. #10
    Registered User
    Join Date
    Mar 2013
    Posts
    43
    You only worry about 3rd gear pulls. Nothing else matters. Only STI with the 6 speed does a log in 4th. So your fine at hat boost and no knock.
    Jeff

  12. #11
    Master Baiter EJ257's Avatar
    Join Date
    Aug 2007
    Location
    On a stream bank somewhere
    Posts
    19,642
    I Support ClubWRX
    Quote Originally Posted by georgia-wrx
    You only worry about 3rd gear pulls. Nothing else matters. Only STI with the 6 speed does a log in 4th. So your fine at hat boost and no knock.
    Jeff
    You aren't likely to downshift into third to pass someone on the highway, so I still like to see 4th logged. '07+ 6M/Ts are typically logged in 3rd gear, as well.
    2005 WRX STi (Mods | Virtual Dyno)

    Resident Tuner @ WTF Tuning, LLC

    "Never trust anything that bleeds for a week and lives ..."

    UNYSOC

  13. #12
    Registered User
    Join Date
    Mar 2013
    Posts
    43
    From Cobb site:

    Data Log Recording
    The first step to taking a good data log is collecting the proper information. If the data log is too short, there won't be enough to data to analyze, and if the data log is too long, there will be too much information to sort through. The best log is safely taken in 3rd gear for a 5-speed transmission and 4th gear for a 6-speed transmission. Start the data log at about 2500 RPM and drive to redline at full throttle. This kind of pull will have the most ideal load on the car in order to provide proper boost characteristics. Once the log is complete, transfer it to the computer using AP Manager and then open it using any spreadsheet program such as Microsoft Excel or OpenOffice Calc.
    Jeff

  14. #13
    Master Baiter EJ257's Avatar
    Join Date
    Aug 2007
    Location
    On a stream bank somewhere
    Posts
    19,642
    I Support ClubWRX
    Quote Originally Posted by georgia-wrx
    From Cobb site:
    I'm aware of what Cobb recommends.

    The gear ratio changed in '07, and there is no equivalent like there was in '04-06 (4th on 6M/T was ~1.3, same as 3rd on the 5M/T). With the new 6M/T gearsets, ratio is ~1.5 for 3rd and ~1.1 for 4th. Since 4th puts the driver well above triple digits, I prefer to see full RPM datalogs on the '07+ in 3rd gear, and logs in 4th through peak torque, the same way I do for the WRX.

    Additional information, especially with a situation you could find yourself in (like downshifting on the highway to make a pass), does matter, as far as I'm concerned. Putting the car into untuned load sites is not a good thing, and, as mentioned, can lead to catastrophic failure.
    Last edited by EJ257; 04-23-2013 at 11:04 AM.
    2005 WRX STi (Mods | Virtual Dyno)

    Resident Tuner @ WTF Tuning, LLC

    "Never trust anything that bleeds for a week and lives ..."

    UNYSOC

  15. #14
    Registered User
    Join Date
    Mar 2013
    Posts
    43
    I see what your saying but in my past experience ain't 1:1 what we want for a true load test. All Dyno tunes are done in a 1:1 ratio to adjust and lock in a tune. I must admit I'm on a new learning curve since leaving the SVT Lightning realm. I'm with you 100% I want to know what my motor is doing in order to extend the life and longevity of my WRX. 4th is he correct gear for the STI and 3rd for the WRX. Forgive me if I'm wrong I do see what your saying.
    Jeff
    Last edited by georgia-wrx; 04-23-2013 at 11:32 AM.

  16. #15
    Master Baiter EJ257's Avatar
    Join Date
    Aug 2007
    Location
    On a stream bank somewhere
    Posts
    19,642
    I Support ClubWRX
    Quote Originally Posted by georgia-wrx
    I see what your saying but in my past experience ain't 1:1 what we want for a true load test. All Dyno tunes are done in a 1:1 ratio to adjust and lock in a tune. I must admit I'm on a new learning curve since leaving the SVT Lightning realm. I'm with you 100% I want to know what my motor is doing in order to extend the life and longevity of my WRX. 4th is he correct gear for the STI and 3rd for the WRX. Forgive me if I'm wrong I do see what your saying.
    Jeff
    Dyno and street tuning are different. That's why every dyno tune should include a road tune to polish it off.
    2005 WRX STi (Mods | Virtual Dyno)

    Resident Tuner @ WTF Tuning, LLC

    "Never trust anything that bleeds for a week and lives ..."

    UNYSOC

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •