Close

Results 1 to 10 of 10
  1. #1
    Join Date
    Sep 2012
    Posts
    44
    Rep Points
    91.2
    Mentioned
    12 Post(s)
    Rep Power
    0


    Reputation: Yes | No

    strange whoosh + overboost ... hard to explain

    while driving to work today, i noticed something off w/ car.

    i was doing runs last night and the car was working flawlessly (cobb S1+aggST)

    note: i have ER chargepipe w/ tial bov.

    so, if i accelerate and quickly let off gas, there is a whoosh sound (not bov sound) as if it was not venting properly. immediately following the sound, i notice that rpm's bounce upward for a second as if overboost was forcing way into the combustion process. sorry but the issue is very hard to describe.

    i attempted to log but couldnt get anything reliable on way to work. no codes thrown. will try to get some reliable logs tonight.

    i plan on checking vacuum lines and bov tonight and see what i can find.

    anyone have experience w/ any issues like this? any ideas?

    thanks.

  2. #2
    Join Date
    May 2012
    Location
    Jacksonville, FL
    Posts
    2,937
    Rep Points
    2,858.9
    Mentioned
    78 Post(s)
    Rep Power
    29


    Reputation: Yes | No
    Do you get a "shove from behind" type feeling as well? As if the car wants to keep accelerating after you have let off the accelerator pedal?
    2011 E90 M3 \ Melbourne Rot Metallic

    Click here to enlarge

  3. #3
    Join Date
    Oct 2012
    Location
    AZ
    Posts
    665
    Rep Points
    1,743.1
    Mentioned
    17 Post(s)
    Rep Power
    18


    Reputation: Yes | No
    Had similar issues when my diverter valves were misbehaving.

  4. #4
    Join Date
    Sep 2012
    Posts
    44
    Rep Points
    91.2
    Mentioned
    12 Post(s)
    Rep Power
    0



    Reputation: Yes | No
    Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
    Do you get a "shove from behind" type feeling as well? As if the car wants to keep accelerating after you have let off the accelerator pedal?
    Yes!

  5. #5
    Join Date
    May 2012
    Location
    Jacksonville, FL
    Posts
    2,937
    Rep Points
    2,858.9
    Mentioned
    78 Post(s)
    Rep Power
    29


    Reputation: Yes | No
    Click here to enlarge Originally Posted by nelsonmg Click here to enlarge
    Yes!
    I get it also, but it hasn't bothered me enough yet to attempt to try to tune it out. Basically you are overshooting your load targets and the throttle plate is slow to snap shut. Getting a protune will take care of it, or you could try to fix it yourself, but unfortunately i don't have any tips for getting rid of it at the moment. Switching to Linear Throttle mapping seems to help, but if you are auto you may not like the way the throttle mapping feels.
    2011 E90 M3 \ Melbourne Rot Metallic

    Click here to enlarge

  6. #6
    Join Date
    Sep 2012
    Posts
    44
    Rep Points
    91.2
    Mentioned
    12 Post(s)
    Rep Power
    0



    Reputation: Yes | No
    Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
    I get it also, but it hasn't bothered me enough yet to attempt to try to tune it out. Basically you are overshooting your load targets and the throttle plate is slow to snap shut. Getting a protune will take care of it, or you could try to fix it yourself, but unfortunately i don't have any tips for getting rid of it at the moment. Switching to Linear Throttle mapping seems to help, but if you are auto you may not like the way the throttle mapping feels.
    werd. its a pretty $#@!ed up noise/feeling. how long has the issue been present on your car? think it is bad for engine to let it persist? i didnt have any issue w/ any of the sport maps only aggressive. let me know if you figure anything out and i will do the same.

  7. #7
    Join Date
    Sep 2012
    Posts
    44
    Rep Points
    91.2
    Mentioned
    12 Post(s)
    Rep Power
    0



    Reputation: Yes | No
    Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
    I get it also, but it hasn't bothered me enough yet to attempt to try to tune it out. Basically you are overshooting your load targets and the throttle plate is slow to snap shut. Getting a protune will take care of it, or you could try to fix it yourself, but unfortunately i don't have any tips for getting rid of it at the moment. Switching to Linear Throttle mapping seems to help, but if you are auto you may not like the way the throttle mapping feels.
    does this sound familiar...
    1st instance = between 2-3 sec / 2nd instance = between 32-33
    (occurs right before BOV sound)

  8. #8
    Join Date
    Sep 2012
    Posts
    44
    Rep Points
    91.2
    Mentioned
    12 Post(s)
    Rep Power
    0



    Reputation: Yes | No
    and, as you said tune related. doesnt happen after cobb uninstalled.

  9. #9
    Join Date
    May 2012
    Location
    Jacksonville, FL
    Posts
    2,937
    Rep Points
    2,858.9
    Mentioned
    78 Post(s)
    Rep Power
    29


    Reputation: Yes | No
    @nelsonmg, doesn't sound familiar, but i also don't have DCI which is known to be more "vocal."
    2011 E90 M3 \ Melbourne Rot Metallic

    Click here to enlarge

  10. #10
    Join Date
    Sep 2012
    Posts
    44
    Rep Points
    91.2
    Mentioned
    12 Post(s)
    Rep Power
    0



    Reputation: Yes | No
    Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
    @nelsonmg, doesn't sound familiar, but i also don't have DCI which is known to be more "vocal."
    interesting. definitely got the push from behind feeling.

Tags for this Thread

Bookmarks

Posting Permissions

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