Miata Mailing List: February 1994, Message #412



     


   From: "Matthew J. Bennett" 
Subject: Real data on air filters (K&N, paper, etc)
   Date: Fri, 25 Feb 1994 15:27:20 -0500

Here's something I thought would be of interest, considering the 
talk there has been going on about the K&N air filter.  It may 
not be the wonder-filter everyone says.  I got Ed's permission to
post this here.  I got it off of the BMW motorcycle mailing list.

Matt
hazmat@motor.arl.army.mil
----------------------------- Note follows -----------------------------
From: Ed Hackett
X-Original-Sender: edh@maxey.unr.edu
Date: 25 Feb 94 00:12:40 CST (Fri)


Here's the info I have on air filter performance.  Tests were done using 
SAE J726C Test Method  5-best --> 1-worst

                              Oiled foam    Paper   Oil Bath   Oiled Gauze
                             (AMSOIL, UNI)                        (K&N)

Large particle efficiency          5          5         5            4
Small particle efficiency          5          4         1            2
Airflow capacity                   5          2         3            5
Dust holding capacity              4          2         5            2
Load up characteristic             4          1         5            1
Backfire characteristic            3          2         5            3
Cleanability                       4          1         4            3

As you can see, K&Ns are great for airflow, which is what they were 
designed for.  Their original application was on racing engines, where 
airflow is important and ultimate engine life was of little consern.  They 
are not as good at filtering as paper or oiled foam types.

 Ed Hackett   edh@maxey.unr.edu           The Desert Research Institute 
 DoD #0200  WMTC  BMWRA  DIOC             Reno, Nevada   (702) 673-7380   
 KotLS  KotLE  DotD #0003            I'm not really a chemist, I'm just one of
 900SS  K100RS  501 CAMEL            them motorsickle sonsabitches.  __=o&o>__