Hallo Satmark !
Zitat:
|
wie ich schon gelesen habe, seid Ihr, genau wie ich, Befürworter von K&N-Tauschfiltern
|
Wer ist
"ihr" ?
Ich nicht !
Wenn man seinem Motor einen Gefallen tun will,
benutzt man einen möglichst "engmaschigen" (Mikrometerbereich)
und großflächigen Filter.
Das sind Papierfilter oder Schaumstofffilter.
Die Filter von BMW sind als bester Kompromiß auf den Motor abgestimmt.
Rennmotore, die nur ein paar hundert oder tausend Kilometer fahren müssen,
kann man mit offenen Lufttrichtern und Sieb betreiben,
weil sie dann sowieso überholt werden (müssen).
Kommt natürlich auch dran an, wo man rumfährt und wie
hoch die Partikelbelastung der Luft dort ist.
Aber wenn man die halbe Milliion km vollmachen will,
ist das nicht der richtige Weg.
Es sei denn, man wechselt alle 5oookm das Motoröl.
Untersuchungen des Motoröls haben ergeben,
daß die Belastung des Öls mit angesaugten Feststoffen
ein vielfaches höher ist als mit Papierfiltern,
bei gleicher Nutzungsdauer und Betriebsbedingungen.
Man hat also eine Art "Schmirgelpaste" im Motor. Nein Danke !
Hier mal der Bericht eines Tests zwischen BMW M3 Original Papierluftfilter
und K&N Luftfilter.
=================================================0
Are "Performance" Air Filters a Good Idea?
The following information was taken from a posting by Jim Conforti (AKA the Land Shark). Jim is a well known tuner in BMW circles. His web site is the Bonneville Motor Werks. The testing was done on a BMW air filter but the concepts should apply to all manufacturers.
Comparing Stock to Performance Air Filters
First, a "prologue". This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark"
.
OK, with that in mind, onward.
A scientific test was done on TEST filters where air was loaded with ACCTD (some standardized "test dust" called AC Coarse Test Dust) and sucked through the TEST filter then through an analysis membrane.
From the Quantity of dust injected and the amount that gets thru the TEST filter and is then captured on the analysis membrane we can calculate the efficiency of the TEST filter in Question.
First, the filters:
BMW Stock Filter, Eff. Area of Media: 8.4 sq ft.
K&N Replacement, Eff. Area of Media: 1.6 sq ft.
The filters are the SAME size. They both fit in the STOCK BMW M3 airbox. The difference is that the STOCK filter has 65 pleats 1.5" deep and the K&N only 29 pleats each 0.75" deep.
Now, remember this ratio: " 5.25:1". It's the ratio of the AREA of STOCK to K&N. It's very important and will come into play later.
The STOCK filter efficiency started at 93.4% at 0 loading and increased to 99.2% efficiency as the loading increased to a max tested of 38.8 gm/sq ft of dust.
The K&N filter efficiency started at 85.2% at 0 loading and increased to 98.1% at the max tested loading of 41.38 gm/sq ft.
Now, I hear you. "Jim, that's only a FEW PERCENT". But is it?
Let's look. If we had 100 grams of dust on a new BMW filter we would let thru a total of 6.6 grams of dust in. If we used the new K&N filter we get 14.8 grams of dust. Thats 224% (TWO HUNDRED TWENTY FOUR PERCENT!!) more dust ingested initially, stock vs. "free flow" and this ratio is pretty much held. Somewhere between 200-300% more dirt gets "ingested" anywhere across loading equivalence.
The more INTERESTING thing is when you look at what happens to the DP or Differential Pressure at a constant airflow as you dirty both filters equally with time.
The test used a rate of 75gr of dust per 20 min. Here's where the AREA difference comes MAJORLY into play. See, even though the BMW filter flows a bit less at the SAME loading, it also LOADS UP 5.25 times SLOWER due to it's LARGER effective area. So what happens is that the K&N initially flows better, but as the dirt continues coming in, the K&N eventually flows WORSE while still letting MORE dirt in.
Now, does any of this additional dirt cause problems? I dunno. I suppose we could have a few people do some independent oil analyses on different motors using both K&Ns and Stock filters. Get enough of them, and you'd have a good statistical basis. For me though, it's simple: More DIRT = BAD.
The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.
-- Jim Conforti
================================================== ===
So, hoffentlich habe ich Deine Vorfreude nicht zu sehr getrübt.
Mir jedenfalls kommt so ein Ding nicht unter die Motorhaube
Ich verzichte gerne auf eventuelle, kurzfristig höhere
(kaum meßbare und meist nur subjektiv auf Grund von mehr Lärm empfundene) Leistung
zu Gunsten eines gesunden, langlebigen Motors
Gruß Manu
Sie sind nicht angemeldet! Jetzt 
kostenlos im Forum registrieren, weniger Werbung sehen, aktiv teilnehmen und weitere Vorteile nutzen! Diese Website nutzt Cookies. Bitte beachten Sie unsere 
Kleiner Tip am Rande zu K&N-Filtern
Linear-Darstellung
