Originally Posted by BMRLVR
Give me a break, you think I don't know about the principle of an oiled cotton and gauze filter.
If they filter so well, why is it recommended for you to use a filter sock on motocross bikes or ATV's? The reason is that an oiled cotton and gauze filter will let in enough dirt to dust the engine on those machines!!! I have seen it first hand!!!
You go ahead and use your aftermarket filters if you like, for maybe a 2HP gain I think I will choose to forfeit the 2HP and protect my engine!
The only filter upgrade I recommend is using the Euro Filter on 08 - 09 north american M3's
P.S.: I have done hundreds of hours of technical training on oil, fuel and air filtration! The engines I work on are close to $1million a pop so the company I work for is big on filtration and engine cleanliness in general!
Geez don't bite my head off. I don't know your experience or expertise. If you think about it the average person here probably does not know how those filters work but in fairness to me, you posted the statement above that said (I paraphrase) "the only way a filter lets in more air is if there is more holes and lets in more dirty."
Which is not true as you seem to acknowledge to know that oiled filters can have bigger gaps that let air but use the oil to catch the dirt.
Chill man! I did not know you are an engine builder. Cool gig!