No announcement yet.

Forum Top Advertisment


K&N Sucks (dust)

  • Filter
  • Time
  • Show
Clear All
new posts

  • K&N Sucks (dust)

    Recent DNF at NASA Buttonwillow Enduro was caused by my K&N air filter fail

    As you know the dust at Buttonwillow is fine lake bed sediment. With no wind the night of the race every Miata that dropped wheels off, and yes I mean you Miata drivers, stirred up a perpetual cloud of dust that just hung around. The dust was so bad that it later rained down in the pits.

    This fine dust just went right through my K&N air filter. Which then clogged the Manifold Pressure Sensor. The MAP then thought it was at 30,000 feet elevation and the ECU then leaned the fuel out to 30 to 1. This resulted in a loss of power, which led me to DNF. On tear down the entire intake was coated with dust.

    K&N sucks dust. I'm going with paper filters from now on.

    Here is a test showing that K&N doesn't even perform better than paper, new or used.
    "Effect Of OEM Style And Aftermarket Performance Air Filters On Vehicle Parameters"

    To quote the reference paper:
    Fig 3 shows that K&N filter exhibits higher resistance to air flow compared to OEM filter in both new and clogged condition.

  • #2
    Yes but in that same PDF see table 6 and 7, the KN filter yields better fuel economy and faster acceleration than oem despite the other tests it fails. Further below EGT are lower with the KN too. The only important thing is performance.


    • #3
      The K&N benefit is more or less straightforward. They have less flow resistance because they filter less. Want a gnat's ass better performance at the expense of running particles through the engine, then giddy up on the K&N. Heck, want even more performance.... just remove the damn filter. There's a reason that the OEM's - pretty much universally, have stayed with paper air filters.


      • #4
        K&N have a min micron particulate filtration limit when oiled. Forget what it is but it's significantly larger particle than the best paper filters. I have switched over to dry filters for that reason. Dry fabric or dry paper. My favorite were AEM dry filters before they changed. Other issue with oiled fabric filters is if you are sloppy with oil application it can get on MAF (hot wire) and other sensors downstream and foul them.

        WRT to Miata drivers dropping wheels. Of course, it was only Miatas drivers dropping wheels and no other cars. The lack of any breeze and the type of dust having no bearing on the condition. FWIW, there is always hanging dust in the air in Enduros at BRP. Always. It's worst right at sunset when drivers with dirty shields or poor muscle memory can't hit apexes and fly off in the low light

        Aside from their cost I never understood why people race them.
        But obviously I just dont get it. -fatbillybob


        • #5
          That seems to be the prevailing wisdom. Use regular old paper filters and replace often.