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mb911 mb911 is offline
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Join Date: Jan 2003
Location: Burlington, Wisconsin
Posts: 9,312
[QUOTE=DonE;3789943]I've been running a KN filter on mine for the last seven years. I've had the engine apart three times and have not seen any damage due to dirt being sucked in past the filter (including the turbo compressor blades). On the other hand, I maintain my filter at each oil change. I also have an EFI motor with a wire air intake sensor and don't think twice about oil getting on it - it would have to travel through the turbo and intercooler first which is highly unlikely.

I have also seen "performance shops" fab EFI intakes that place a KN filter in the rear fender well (behind the tire!), subject to road dirt and rain water. Although I have not had a problem with a KN filter, I would never subject it to that kind of treatment.

The high HP general aviation aircraft I work on don't use filters, however they are still approved for grass strips. If we think we will be at a lot of grass strips (air show work), we will install a KN type filter - and this is on a two-stage supercharged $125,000 motor.


Climate has a huge thing to do with the filters. all of the light aircraft I dealt with were running the same kind of RPM out 911 engines run and of the several hundred I have rebuilt in my past life 25% of them failed from foreign matter injested from the K&N filter now these were 2 and 4 cylinder boxer engine's and a good portion turbocharged (think unmanned predetor)
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Ben

914-6 2.4s GT tribute.
914-6werkshop.com manufacturer of 914-6, GT, Conversion parts
Old 02-25-2008, 04:55 AM
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