1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Forge Motorsport

Discussion in 'A3/S3 Forum (8L Chassis)' started by Jays Audi Turbo, Jan 31, 2010.

  1. Jays Audi Turbo
    Offline

    Jays Audi Turbo I Love Boost :-)

    Joined:
    Jan 26, 2010
    Messages:
    85
    Likes Received:
    0
    Last edited by a moderator: Jan 31, 2010
    #1
  2. jojo
    Offline

    jojo S3 Drift King! Staff Member Moderator

    Joined:
    Sep 4, 2003
    Messages:
    25,925
    Likes Received:
    1,558
    #2
  3. Jays Audi Turbo
    Offline

    Jays Audi Turbo I Love Boost :-)

    Joined:
    Jan 26, 2010
    Messages:
    85
    Likes Received:
    0
    Thanks for the guide m8 but what does it improve once fitted
    #3
  4. jonny87
    Offline

    jonny87 Active Member

    Joined:
    Sep 24, 2009
    Messages:
    1,098
    Likes Received:
    3
    no improvements mate, the secondary air injection pump is a common failure on these cars, unsure why, but the car will run unaffected if removed, the later model of s3's ie amk and bam engines dont have these at all as audi realised they are pretty pointless

    couple hours work to remove, see my guide as jojo posted if you going to have a go at it
    #4
  5. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    SAI is there for controlling emissions (adds air to the exhaust on sold start), typically VAG approach with solonoid valves and rubber hoses that just split and leak all over the place. Typically its fine to remove but leave the solenoids etc electrically connected to stop fault codes etc...

    <tuffty/>
    #5
  6. jonny87
    Offline

    jonny87 Active Member

    Joined:
    Sep 24, 2009
    Messages:
    1,098
    Likes Received:
    3
    tuffty, how exactly does the sai work, one pipe airbox to pump then another pipe pump to combi valve/block

    it either draws cold air into the engine from air box, or pumps warm air into air box from engine?

    cant see how its supposed to warm your cat up quicker?
    #6
  7. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    Wasn't sure exactly so after a bit of googling, the secondary air system is an emission related system that injects extra oxygen into the exhaust pipe to burn off any extra fuel. The system only activates on cold starts (when the coolant temperature is between 15 and 35 degrees Celsius). The system consists of a large air pump, one or two combi-valves and a solenoid. The valves are controlled via vacuum lines that cause them to open and close.

    <tuffty/>
    #7
  8. Jays Audi Turbo
    Offline

    Jays Audi Turbo I Love Boost :-)

    Joined:
    Jan 26, 2010
    Messages:
    85
    Likes Received:
    0
    Whats the n249 bypass mod its mentioned on the sai removal guide
    #8
  9. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    N249 valve is used by the ECU to control actuation of the DV. Normally the DV only needs to be opened when it sees vacuum (changing gear for example) but the N249 is used to allow the ECU to vent boost when 'it' wants...

    Bypassing the N249 (known as 'deleting') improves the response time of the DV but 'can' lead to boost spikes particulary on smaller turbos...

    <tuffty/>
    #9
  10. jonny87
    Offline

    jonny87 Active Member

    Joined:
    Sep 24, 2009
    Messages:
    1,098
    Likes Received:
    3
    #10

Share This Page