2006 X3 cold air intake vs. K&N filter for stock airbox

Hey guys.. I have a 2006 BMW X3 3.0i and I was wondering.. I used to have a cold air intake on my Passat and of course I know about the aFN intake for my X3, which is the only intake I've been able to find. On my Passat I had a Neuspeed CAI with a K&N filter.

I searched on Dinan's site and didn't find any air intakes for the X3..

My dilemma is that a lot of the use of my X3 is going to be for taking my dog, and future dogs to different places. I heard the aFN intake is loud.. and I mean I remember my old intake but someone quoted 90db in the cabin or something like that.

So my question to you guys is do I really need a full blown cold air intake system? I have never touched the airbox on my X3 so I haven't seen it but on the Passat it was just this box with a HUGE air filter in it that was very thick, and of course that is where I pretty much saw all the restriction of the air flow.

On the X3 I notice there's a thin tube coming from where the air enters the vehicle going into the stock air box, and the aFN filter looks like the stock airbox but it has a round filter in it.

The K&N filter looks like a really small filter compared to the one that was in my Passat. I mean, for all cars even the stock K&N filters aren't no where near as big as the OEM one from my Passat..

So is there really any advantage at all to getting a full blown air intake besides the sound? I'd like the extra power and mpg increase from having a better filter/intake and wonder if just replacing the stock filter with the K&N one will do the job.

Also of course I'd rather not void the warranty on the car.

Thanks.

fox, you probably don't have much warranty left with an '06. I just ran mine out last month (50K miles). That said Dinan used to have an air system for the X3, unfortunately it was not blessed by our omnipotent CARB here so was not available to CA residents. If you are interested in a Dinan system give them a call and ask what they have. Great people there and always happy to help. I remember them having 4 things for the X3 (up to '06), a strut brace, cat back exhaust, cold air system, and a chip. There have been other posts that mentioned a slight gain in discernable (seat of the pants) performance after installation, but not much. For real performance in your X3 a blower is really the only way to go IMHO, and at least two companies make the kit for the pre '07 X3.

To gain appreciably more power you have to flow air THROUGH an engine. This means more air in, more air out.

To flow more air through the engine you need a bigger exhaust system and this runs the cost way up. The $ per HP is really expensive in my opinion anyway.

I'm not trying to get the max power I can out of the vehicle.. Mostly I was wondering if you really need to get a full blown intake system vs. just the K&N filter to see the performance gain of an intake..

I mean because they advertise all these crazy numbers but I know the performance upgrade is really slim and I can hear the intake now when I press the gas it's just a lot quieter but it sounds the same as when you have an intake (like the gurgling sound) so.. i think the reason it's louder is because it doesn't have as much material blocking the sound but I am not sure that that necessarily means it's more POWERFUL just because it's louder, like they claim.

Bavarian Auto http://www.bavauto.com/shop.asp has them but they're pricy ($394)

FWIW:

For one of my other vehicles, the Sky Redline, we've spent significant time on the skyroadster.com forum debating these issues.

When all is said and done with, the K&N and CAIs don't make huge performance differences (multiple members checked with dynos pre/post mod), if any at all. For the people doing the CAI, it really boiled down to the "nicer sound" and being able to hear the blowoff valve and the turbo spooling, less so any true performance gain. Having said that, I should point out that members who changed to CAIs with concomitant exhaust changes were able to demonstrate appreciable increases in horsepower.

I will tell you that I just put a K&N in my 2009, and it hasn't made any leaps and bounds in "seat of the pants" power, but my MPG has improved significantly (from 23/24 HWY to about 25-27 HWY).

With our normally aspirated, non-turbo engines, I am not sure a CAI would make "that much" noise. May be worth calling BavAuto to get their thoughts on that aspect.

Good luck.

Yeah I'm more interested in the MPG upgrade. I know that the performance upgrade won't be that much. I don't even know how they can get away with advertising 20HP increases. it's like every site says something different.

The factory warranty on my X3 is up next May, but I have the CPO extended warranty. Not really trying to void the warranty because I like going in to service and not having to pay for anything.

I would be lying if I said I wouldn't like the nicer sound but I know my dog won't and in the future I plan to be rehabilitating dogs with issues and I can't have something that's gonna really bother them. Now again, it may not be all that loud to where it would bother them, but that's a $360 gamble.

What I don't get is their claim that the stock airbox causes the restrictive airflow. Maybe the stock filter? I haven't looked inside the stock airbox, but I do notice the pipe the air comes in from is really thin, and I would think the bottleneck of airflow would be there? unless there's some kind of maze the air has to go through inside the box.

I didn't really tear my stock box apart, since I am a little leery of tinkering with this "new-fangled" E83, what with all of the electronannies and all (I'm an old school E30 fan), but I would surmise it has tons of stupid plastic baffles, etc. in it just like my Sky does.

Some of the Sky folks have opted to carve out the baffles/mod the airbox structure itself in lieu of the CAI/K&N approach, exactly for the same reasons you are looking for. They did NOT want a noisier result, but wanted less restrictive airflow.

I don't know anyone who has tried this approach with the E83, since most are still under warranty and there is a sad paucity of performance parts for it.

I'll bet someone's going to take a Dremel tool to the airbox @ some point though