I'm considering putting a K&N filter into my 2001 Z3 2.5i, as an interim modification until I go with a cold-air intake system. Are the benefits of a K&N filter worthwhile, or should I just hold out until the cold-air system?
It depends how long its going to be till you get a cold ait intake. I personaly prefrer foam filters, is use ITG filters.
what cold air system you going with? Dinan I presume... IF thats the case hold out on a flter just stick with paper and then use the Dinan filter till it needs replacement then get a foam filter... Dinans filters are not washable... I got a ITG filter they are really nice a little pricey but when it filters the air going into my car, or any car for that mater I wont skimp.
I personally don't see the point of shelling out $300 to $500 for about 2 measurable hp. I installed the K&N flat panel OE replacement filter and removed the inlet restriction for the stock airbox and left it at that. I've gained the advantage of a less restrictive air filter, i'm ingesting relatively unheated air from behind the headlight and it only cost $35 For me, the $$/hp ratio of a CAI (especially if its carbon fiber) just isn't there.
"Fogged" airbox mod for Z3 You might want to check http://www.mz3.net/articles/149.html. I "Fogged" my 97 Z3 1.9l and love the results. It cost about $30 including the filter.
Then it should really impress you by the amount of thought that BMW put into the stock intake system. If you want some underhood eye candy or you like lots of intake noise, feel free to waste your time, money, and effort. But if you want performance enhancement, you're better off spending the money on a chip and saving up for the $5K of machine work that your head will take in order to be able to need a modified intake system.
Not really. I think your average BMW owner probably would think it's too loud anyway. Just as a typical BMW owner would think a nice set of springs and struts are too stiff. Same reason why we have water temp gauges that pretty much always read center whether at idle or 80 mph. All to satisfy the typical BMW owner. And if it was such a fine engine, there would be no need to a chip (or flash) to tune the motor. Let's just say, not all of us are typical. And nothing sounds finer than a CAI at WOT. I don't care if it gives me -5 hp.
That's why I love these forums- I know that there are two sides to every argument! I just like to get both sides before I decide on a course of action.
Not really, it is a very popular modification and if BMW put so much thought into it wht did they have to add the little protrusion? It was to keep throttle noise down!
Every design element of these wonderful cars is a balance of compromises by the engineers and marketing folks who created them and every modification is a decision by the consumer to change the parameters of the original compromise. I personally like my car to be a bit edgier than the majority of the millions of new BMW buyers would probably appreciate. So I've done my research and made my decisions to make it MY car instead of just another unit off the production line.
It is a very simple and inexpensive mod, that merely takes advantage of BMW's fuel/air management system, which is excellent in it's own right. Regarding increased intake noise, the system uses the stock airbox and lid. I noticed a slightly throatier tone @ WOT, certainly not offensive to say the least. I still have the stock exhaust, and expect it is keeping things at a typically reserved German level.
It's reasonably intuitive. Here is a thread from Bimmerforums.com on the subject. http://forums.bimmerforums.com/forum/showthread.php?t=644346&highlight=acoustic horn surgery When I did it on my M, I removed the horn rather than cutting as described in the Bimmerforum thread.
