Posted by Paul H. on January 07, 1999 at 20:13:01:
In Reply to: Re: M50 Engine aircleaner options posted by Kiani on January 06, 1999 at 19:50:11:
: : That would depend on your criteria for "better"
: : Air flow, filtration, noise???
: I would assume that the filtration is the same with any of these setups.
: I would assume that the increase in noise with a cone filter is equal to a mild exhaust system upgrade.
Opinion is divided on this issue. I think the the OEM paper element offers the best compromise between filtration and air flow. K&N filters reportedly allow greater ingress of particles, so I do not think it is safe to assume that filtration will be the same. In any case, the OEM element has a largish surface area, so I am not sure that it would really cause significant impediment to air flow. (Of course, I don't have laboratory data to support this!)
Using cone filters you lose the cold air intake from the front of the car. In my case, at least, with the M30 engine, the air intake sits above the exhaust manifolds. Which, I imagine, is quite a hot spot.
These factors tend to make me stick with the stock filtration arrangement for my car ('90 535i).