Nythän tätä keskustelua vapaavirtaussuotimista vuosikausia seurailtuani ja faktoja eri puolilta tongittuani, ja itsekin aikoinaan sellaisiin sortuneena (Neljä Pipercrossin suodatinta kahden tupladellorton perässä "trumpettien" päällä) voin vain todeta seuraavaa:
Ns. vanufiltterit ovat vanhanaikaista teknologiaa. Ennen muinoin kaikki autojen ilmanpuhdistimet olivat öljyttyjä "vapaavirtaussuodattimia".
Sitten jossakin 50-70-lukujen välillä tekniikka kehittyi ja koneita tehtiin huomattavasti pienemmillä toleranssilla. Oli pakko löytää vaihtoehto jolla koneeseen ei enää pääsisi yhtä isoja partikkeleita kuin aikaisemmin. Keksittiin vaihdettavat paperifiltterit joilla koneeseen ei enää päässyt isoimpia "kivenmurikoita" ja moottoreista pystyttiin tekemään hyvinkin tiukoilla toleransseilla tehokkaita, korkeampipuristeisia ja taloudellisia.
Kunnes "uutena" muoti-ilmiönä pestävät, öljytyt vapaavirtausfiltterit löysivät tiensä kilparadoilta takaisin kaduille, ainoana erona että ne eivät enää olleet kiinni uutenakin väljissä sivuventtiilikoneissa joista isommatkin partikkelit menevät läpi nin että kolisee, vaan huipputeknologialla minimaalisilla toleransseilla valmistetuissa tihdeissä (joskus jopa hädin tuskin sisäänajetuissa), moderneissa moottoreissa jotka kuluvat huomattavasti ennen aikojaan saadessaan liian suuria partikkeleita (lue: hienoa pölyä) sisäänsä.
Lyhyestä virsi kaunis mutta todettakoon että mainitkaa YKSI AINOA autovalmistaja jonka uuteen autoon voit pultata K&N virifiltterin, viedä auton huoltoon ja jossa on vielä moottorissa takuu jäljellä tuon huoltokerran jälkeen. Mielellään liikkeen nimi, yhteyshenkilön nimi ja puhelinnumero mukaan koska muuten en tosiaan usko.
Eli ei kannata uskoa ihan kaikkea mitä tuningheebeliliikkeen niljake tai virifiltterivalmistajan kotisivu antavat ymmärtää. Jos autolla on tarkoitus ajaa vain joitakin satoja kilometrejä ennen täyttä koneremonttia, tai kuten kiihdytysautoissa vain noin 400 metriä, niin samahan se paljonko sieltä menee paskaa läpi. Vaan kun nykyaikaisella henkilöautolla yleensä ajetaan sentään 300,000km ja mersuilla useimmiten yli 600,000km niin tarkoitus olisi pitää pölyt koneen ulko- eikä sisäpuolella.
Tässä vielä yksi näpsäkkä artikkeli asian tiimoilta, valitettavasti kolmannella kotimaisella mutta opettavaista tekstiä yhtä kaikki:
Tallennettu kovalevylleni nimellä: "K & N is crap"
Article: 70180 of rec.autos.tech
From:
neh2@po.CWRU.Edu (Nathan E. Heid)
Newsgroups: rec.autos.tech
Subject: K&N... questions, answers, and challenge
Date: 27 Mar 1995 22:56:10 GMT
Organization: Case Western Reserve University, Cleveland, Ohio (USA)
I've been reading the recent posts regarding K&N air filters--one from a happy customer and then the responses of doubt and distrust of the K&N. This is starting to look like a miniature version of the Slick 50 thread. There seems to be quite a few opinions but very little evidence. There's been a lot of quoting and paraphasing of K&N's advertizing, but not much hard evidence as to the ability, lack of ability of the product to filter air. The views of the posts seem to fall into the following catagories...
K&N filters do nothing beneficial.
K&N's boost performance
K&N's boost performance but do harm by admitting dirt
K&N's boost performance and filter better than paper
Subj: K & N filters
To: John M.
Saturday, January 21, 1995 5:14:10 PM
From: George Morrison
John: If I wrote "subjective" I meant "objective"
.. I was responsible for evaluating re-usable air filters for a major construction/mining company that had hundreds of vehicles ranging from large earthmovers to pick-up trucks and salesmen's cars. This study was embarked upon due to the fact that we were spending upwards of $30,000 a MONTH on paper air filters. Using them one time then throwing them away.. I inititated the study in that I was convinced that a K&N type filter or oiled foam would save us many dollars per year in filter savings, man hour savings, and of course engines as these would filter dirt better than paper. (yes, I had read the K&N ads and was a believer)
Representative test units were chosen to give us a broad spectrum from cars right through large front end loaders. With each unit we had a long history of oil analysis records so that changes would be trackable. Unfortunately, for me, every single unit having alternative re-usable air cleaners showed an immediate large jump in silicon (dirt) levels with corresponding major increases in wear metals. In one extreme case, a unit with a primary and secondary air cleaner, the secondary (small paper element) clogged before even one day's test run could be completed. This particular unit had a Cummins V-12 engine that had paper/paper one one bank and K&N/paper on the other bank; two completely independent induction systems. The conditions were EXACTLY duplicated for each bank yet the K&N allowed so much dirt to pass through that the small filter became clogged before lunch. The same outcome occured with oiled foams on this unit.
We discontinued the tests on the large pieces almost immediately but continued with service trucks, formen's vehicles, and my own company car. Analysis results continued showing markedly increased wear rates for all the vehicles, mine included. Test concluded, switched back to paper/glass and all vehicles showed reduction back to near original levels of both wear metals and dirt. I continued with the K&N on my company car out of stubborness and at 85,000 miles the Chevy 305 V-8 wheezed its last breath. The top end was sanded badly; bottom end was just fine. End of test.
I must stress that EVERYONE involved in this test was hoping that alternative filters would work as everyone was sick about pulling out a perfectly good $85 air cleaner and throwing 4 of them away each week per machine... So, I strongly suggest that depending upon an individual's long term plan for their vehicles they simply run an oil analysis at least once to see that the K&N or whatever alternative air filter is indeed working IN THAT APPLICATION... It depends on a person's priorities. If you want performance then indeed the K&N is the way to go but at what cost??? And no, I do not work for a paper or glass air filter manufacturing company nor do I have any affiliation with anything directly or indirectly that could benefit George Morrison as a result..
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-- Ross Gunn, Ottawa, Canada Voice: 613-746-1817 FAX/Modem: 613-748-6077