KN Filters
11-07-2006, 09:08 AM
#1
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KN Filters
Anyone put a KN Filter in their RS4?
I'm being told that the S4 airbox is the same as the RS4, ergo, the 33-2209 should fit.
Anyone disagree? Anyone know anything else?
I'm being told that the S4 airbox is the same as the RS4, ergo, the 33-2209 should fit.
Anyone disagree? Anyone know anything else?
11-07-2006, 10:03 AM
#5
interestingly enough
K&N's own tests show that the MAF problems it has seen are predominently due to dirty MAF sensors. They do not find K&N oil on the sensors, however, a conclusion that the sensors are failing due to being dirty begs the question:
"How did the MAF sensor get dirty in the first place?"
On bobistheoilguy, one concensus that appears is that K&N air filters seem to show up on oil analysis with increased levels of wear, and elevated silicon levels. (The primary bad contaminant in the intake system.)
I would suggest that anyone who uses a K&N filter, first do a used oil analysis (UOA) as a baseline, with the factory filter. Then replace it with you K&N and do another UOA after the same oil interval, and compare the results. If you do not see increased wear metals or silicon, then you're good to go.<ul><li><a href="http://www.knfilters.com/MAF/MAFTestresults.htm">http://www.knfilters.com/MAF/MAFTestresults.htm</a</li></ul>
"How did the MAF sensor get dirty in the first place?"
On bobistheoilguy, one concensus that appears is that K&N air filters seem to show up on oil analysis with increased levels of wear, and elevated silicon levels. (The primary bad contaminant in the intake system.)
I would suggest that anyone who uses a K&N filter, first do a used oil analysis (UOA) as a baseline, with the factory filter. Then replace it with you K&N and do another UOA after the same oil interval, and compare the results. If you do not see increased wear metals or silicon, then you're good to go.<ul><li><a href="http://www.knfilters.com/MAF/MAFTestresults.htm">http://www.knfilters.com/MAF/MAFTestresults.htm</a</li></ul>
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11-07-2006, 10:12 AM
#8
AudiWorld Super User
I wouldn't put a K&N in the RS4 but is the S4 - RS4 airbox really the same?
K&N's are know for:
1) foiling MAFS
2) K&N over rates the flow
3) Over- or under-oil them and it's trouble
4) The filter is usually not the intake bottleneck
That said, I used to run them unoiled on a race bike. They flow better than paper when unoiled but are mere gravel strainers that way.
Last year I made numerous back-to-back drag strip comparisons of unoiled K&N's, no filters, and the factory pleated paper filters on my E39 M5 and saw no difference in trap speed.
1) foiling MAFS
2) K&N over rates the flow
3) Over- or under-oil them and it's trouble
4) The filter is usually not the intake bottleneck
That said, I used to run them unoiled on a race bike. They flow better than paper when unoiled but are mere gravel strainers that way.
Last year I made numerous back-to-back drag strip comparisons of unoiled K&N's, no filters, and the factory pleated paper filters on my E39 M5 and saw no difference in trap speed.
11-07-2006, 10:26 AM
#10
here's a few links about K&N filters on BITOG
http://theoildrop.server101.com/forums/showflat.php?Cat=0&Number=740101&page=0&am p;fpart=2&vc=1
http://www.bobistheoilguy.com/airfilter/airtest1.htm
http://bobistheoilguy.com/airfilter/airtest3.htm
http://forums.rennlist.com/rennforums/showthread.php?t=306584
http://www.bobistheoilguy.com/airfilter/airtest1.htm
http://bobistheoilguy.com/airfilter/airtest3.htm
http://forums.rennlist.com/rennforums/showthread.php?t=306584
