Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Air filter: OEM vs K&N vs BMC(street, race)

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by tonee, Aug 26, 2010.

  1. As stated, which do you recommend and why?

    I ride a CBR600RR 04, not doing any track work(or atleast not any time soon) but only for daily commuting.

    I've been reading lots of opinions online and it got quite confusing.

    Also if anyone knows, what's the difference between street and race? Can I use race for street use?(yes its a stupid question but someone might be able to shine some good light into me)

    EDIT: ok I've read more about street vs race BMC, race doesn't filter as well as street hence allowing more air flow which can damage the engine.

  2. No idea about the BMC street/race options so I'll stick with what I know:

    OEM - generally a cheap paper element filter. Not bad flow, filtration good enough for most uses.

    K&N - cotton gauze, thus washable and reusable. Slightly higher flow rate and better filtration than paper element. Very expensive, but widely acclaimed to be the best. Downside is that they're American.

    Unifilter - synthetic foam, washable and reuable. Very high filtration, and better flow rate than paper element. About half the price of K&N filters, and they're Australian. No problems using them on my bikes.

    There is also 'Redline', an Australian company that does K&N knock-offs that are actually just as good, but a lot cheaper. If you are considering K&N's, track down Redlines and go for them instead. Otherwise I heartily recommend Unifilters.

    Essentially you're looking at a bit more airflow for your engine, and a lot better filtration. You can also reuse the filters by washing and reoiling at service intervals, making them pay for themselves after a few cycles. I would recommend them for that if nothing else, even though the better filtration means a cleaner, potentially longer-lasting engine.

    On street/race, most manufacturers offer a straight-swap for the stock filter and then individual 'pod' filters that need to have the stock airbox removed. The stock airboxes on modern bikes are very good, and most actually add power, so I wouldn't worry about pods. On older bikes (pre '85) the airbox design can be somewhat average, so pods may become a good idea as they increase total filtration area and also airflow. This means more power, when combined with good carburettor tuning.

    Cheers - boingk
  3. thanks for that boingk!
    can't seem to find redline anywhere
  4. Neither can I actually... may not be around anymore? I remember buying a redline filter for a car years ago...and all the web addresses I've tried from memory seem to be inactive. Oh well, I'd probably still go Unifilter anyway.

    Cheers - boingk
  5. I ran a race BMC on my SV with the top completely opened up. Made grabbing big handfuls of throttle alot of fun :) I have a race BMC on my blade too, but not opened up. For my specific bike the k&n has been proven on dynos to actually reduce hp. But thats my specific model.. For no specific reason I'll continue using bmc race filters in my next bikes.