Omega Owners Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

Welcome to OOF

Pages: [1] 2  All   Go Down

Author Topic: What is the real func of sec air injection system?  (Read 3246 times)

0 Members and 1 Guest are viewing this topic.

gsizoli

  • Junior Member
  • **
  • Offline Offline
  • Hungary
  • Posts: 188
    • View Profile
What is the real func of sec air injection system?
« on: 04 February 2009, 16:25:19 »
Hi!

This quetion is addressed for mechanics.
Does anybody know what is the real function of the secondary air injection system?
As I know it's heating the cats till the operating tempearture is reached, (By feeding air into the exhaust manifold (secondary air), CO and HC are oxidized through afterburning at temperatures over 600°C to form water and carbon dioxide. The exothermal reaction also increases the exhaust gas temperature, which warms the catalyist more quickly.
) but a guy says it'"s not heating (it's heated by the exhaust gas) just blows air which mixes with the exhaust gas to protect cats from damage.
Logged

oceansoul

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • Sunbury on Thames - Surrey
  • Posts: 385
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #1 on: 04 February 2009, 17:06:39 »
i dunno what they do, but many people take them out and notice no difference
Logged

markey mark

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • SLady bitshorpe north lincs
  • Posts: 4236
  • banned for repeatedly reneaging on deals.
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #2 on: 04 February 2009, 17:13:49 »
its to fast warm your cats to keep emmisions down ! was only for banding at the time  :y
Logged

RobG

  • Omega Queen
  • *****
  • Offline Offline
  • Gender: Male
  • Bristol
  • Posts: 13831
  • I might have a link, pic or part number for that
    • 16 plate Mokka. Vivaro
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #3 on: 04 February 2009, 17:17:08 »
  The secondary air injection is a system where by air is blown into the exhaust manifolds for the first few minutes of startup, any unburnt fuel then ignites in the front pieps and the cats heat up a bit quicker.

This is done by a large blower which is mounted in the passenger side front wing, the air blows through a tube into the vac operated shut off valve mounted on the radiator (vac operated so when at Wide Open Throttle there is no air injection plus there is ECU control to via a vac valve).

Courtesy of Marks DTM Oct, 2006
« Last Edit: 04 February 2009, 17:18:10 by RobG »
Logged
All that is necessary for the triumph of evil is that good men do nothing.

UPVC windows/doors/fascias/soffit/gutters supplied/fitted

feeutfo

  • Guest
Re: What is the real func of sec air injection system?
« Reply #4 on: 04 February 2009, 17:19:00 »
its only purpose is to make people post questions on here about "whats that horrible noise, whats it for, how do i get rid?" so all can give a unanimous reply.... Unplug it! Thats all it does. :-)
Logged

Martin_1962

  • Guest
Re: What is the real func of sec air injection system?
« Reply #5 on: 04 February 2009, 17:49:16 »
Usual use more energy to create less emmisions 'dangle berries'
Logged

magnul

  • Junior Member
  • **
  • Offline Offline
  • Gender: Male
  • Trondheim, Norway
  • Posts: 157
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #6 on: 04 February 2009, 17:59:29 »
And what's wrong about reducing the CO and HC emissions?
Logged

TheBoy

  • Administrator
  • *****
  • Offline Offline
  • Gender: Male
  • Brackley, Northants
  • Posts: 107031
  • I Like Lockdown
    • Whatever Starts
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #7 on: 04 February 2009, 18:10:34 »
Quote
And what's wrong about reducing the CO and HC emissions?
It doesn't reduce CO(x) or HC though.  It reduces NO(x)
Logged
Grumpy old man

magnul

  • Junior Member
  • **
  • Offline Offline
  • Gender: Male
  • Trondheim, Norway
  • Posts: 157
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #8 on: 04 February 2009, 18:15:58 »
Quote
Quote
And what's wrong about reducing the CO and HC emissions?
It doesn't reduce CO(x) or HC though.  It reduces NO(x)

Reducing CO and HC requires oxidizing conditions (as made by the secondary air). Reducing NOx requires reducing conditions (as made during the rich cycles at closed loop).
Logged

TheBoy

  • Administrator
  • *****
  • Offline Offline
  • Gender: Male
  • Brackley, Northants
  • Posts: 107031
  • I Like Lockdown
    • Whatever Starts
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #9 on: 04 February 2009, 18:17:30 »
Quote
Quote
Quote
And what's wrong about reducing the CO and HC emissions?
It doesn't reduce CO(x) or HC though.  It reduces NO(x)

Reducing CO and HC requires oxidizing conditions (as made by the secondary air). Reducing NOx requires reducing conditions (as made during the rich cycles at closed loop).
Actually, you're right - my mistake for not reading the question fully before reading...
Logged
Grumpy old man

TheBoy

  • Administrator
  • *****
  • Offline Offline
  • Gender: Male
  • Brackley, Northants
  • Posts: 107031
  • I Like Lockdown
    • Whatever Starts
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #10 on: 04 February 2009, 18:19:09 »
But to answer your Q, it doesn't really help enough with emissions to make it worthwhile.  Its removed from later UK spec cars.
Logged
Grumpy old man

magnul

  • Junior Member
  • **
  • Offline Offline
  • Gender: Male
  • Trondheim, Norway
  • Posts: 157
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #11 on: 04 February 2009, 18:32:01 »
AFAIK, at least the 2.2 hasn't got it. I'm a bit curious what replaced it though. Better engine management, or some pre-cat on the down tube or something?
Logged

TheBoy

  • Administrator
  • *****
  • Offline Offline
  • Gender: Male
  • Brackley, Northants
  • Posts: 107031
  • I Like Lockdown
    • Whatever Starts
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #12 on: 04 February 2009, 18:34:13 »
Quote
AFAIK, at least the 2.2 hasn't got it. I'm a bit curious what replaced it though. Better engine management, or some pre-cat on the down tube or something?
nothing replaced it.
Logged
Grumpy old man

magnul

  • Junior Member
  • **
  • Offline Offline
  • Gender: Male
  • Trondheim, Norway
  • Posts: 157
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #13 on: 04 February 2009, 18:39:28 »
Well, it was required to pass Euro2 emissions, so I guess something was done to still pass the later Euro emission codes.
Logged

markey mark

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • SLady bitshorpe north lincs
  • Posts: 4236
  • banned for repeatedly reneaging on deals.
    • View Profile
Re: What is the real func of sec air injection system?
« Reply #14 on: 04 February 2009, 18:52:43 »
Quote
Well, it was required to pass Euro2 emissions, so I guess something was done to still pass the later Euro emission codes.

yep went twin cats and dbw throttle and cpp :y
Logged
Pages: [1] 2  All   Go Up
« previous next »
 

Page created in 0.012 seconds with 17 queries.