Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Please note that it is not permitted to have referral links posted in your signature. Keep these links contained in the appropriate forum. Thank you.

https://www.boards.ie/discussion/2055940817/signature-rules
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

Air filter increases bhp?

  • 31-03-2011 9:08pm
    #1
    Idbatterim
    Registered Users, Registered Users 2 Posts: 18,127 ✭✭✭✭


    Hi, my bro replaced standard air filter on his 02, 318ci with a K&N one, will he get any increase in bhp by doing this, or does the cars computer control everything and hence make it a waste of time?


Comments

  • #2
    mickdw
    Registered Users, Registered Users 2 Posts: 23,688 ✭✭✭✭mickdw


    Hardly worth talking about Id say.
    Does this filter have to be treated with oil before use?


  • #3
    Plug
    Registered Users, Registered Users 2 Posts: 9,248 ✭✭✭Plug


    He might even lose horse power.


  • #4
    Matt Simis
    Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    Idbatterim wrote: »
    Hi, my bro replaced standard air filter on his 02, 318ci with a K&N one, will he get any increase in bhp by doing this, or does the cars computer control everything and hence make it a waste of time?
    Panel or Cone?
    If panel:
    K&N type filters do sometimes show small increases in BHP but they also are sometimes attributed to MAF failures (due to the Oil they use).
    If the stock intake was in anyway restrictive, then its possible to reduce that restriction and get more power. However a 318 is a fairly small motor, so its unlikely it was Air starved.

    The other gotcha on K&N filters is they absolutely will allow more dirt into the engine (google Duramax JCB filter test for figures).

    If cone filter sitting in engine bay
    A K&N 57i type cone filter sitting in the hot engine bay will suck in hot air, making more noise but reducing performance (measurably) as hotter air contains less oxygen.


    Ive done some modding with Air Filters and IMO, the best performing air setup is a Foam Filter (not paper or Oiled mesh, but OEM paper is a close second) in the stock Cold Air Intake with an additional "ram" type air intake plumbed in and all other exits sealed (ie the water drain, poor fitting lit, just make it air tight). You want to have ram air intake "trumpet" type air scoop in a high pressure location on the front of the car getting so much air pushed into it (into an air tight airbox) that you slightly positively pressurise the intake system, which leads to colder air and less/no "sucking" of air by the engine.
    Repositioning the Intake Air Sensor into the airbox would be an improvement too (more accurate reading and wont get heat soaked).


Advertisement