Re: Air Filters

[GRobWorkII@xxxxxxx]

Paliava,

   Beware the savvy marketing of aftermarket air filter manufacturers...  At 
the risk of opening a "digestive can of worms" here, let's just say that 
there are many halfway respectable dyno comparisons showing negligible (0-2 
hp) increases that accompany the use of filters such as the K&N...  The stock 
airbox on your M30 is VERY nonrestrictive, and provides a valuable service 
that some of the aftermarket filters seem to overlook - it actually keeps 
foreign particulate from entering the intake.  To illustrate;  I let my last 
paper filter go for 24k miles.  The incoming air side of the filter and 
airbox were quite nasty, caked with a layer of fine silts and dust... (There 
is an obvious need for filtration of incoming air.)  The intake side of the 
filter and airbox were perfectly spotless.  Would a K&N have filtered the air 
the same?  Questionable...  Is that chance worth 0-2 hp?  Not for me.  Keep 
in mind that as an oiled foam filter gets caked with filth, restriction 
drastically increases.  I'd put my money elsewhere!  

Rob Workman
'85 535i (Holga)

<< Hello,
 
 I would like to install an air filter on my 635CSi '85. What
 cuold you suggest ? 
 I was thinking about K&N, but later I found out that APEX
 makes better performance. But the info I could find about
 APEX was very poor. Maybe anyone knows where it's possible
 to find more info about APEX air intakes ?
 
 paliava
 BMW 635CSi '85
 Lithuania >>

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