Drop in Air Filter Vs. CAI

[RIBEMR26]

Ok, I have read a million old threads. Everyone seems to have a different opinion. CAI vs. replacing the air filter with a "green" or "K&N" drop in? What do you guys think. I mean, is it worth all the work with setting up a "true" CAI and moving the horn and all that, or just "dropping in" a performance filter in the box?

[M3Daemon]

I have no direct comparison and I have not dyno'ed a drop in K&N vs. my CAI, so I can't tell you how much the HP difference would be. I seriously doubt it is more than 2-3HP. You might get a little better air-flow at high speeds with the CAI since it sits free in the bumper.
I would say it's a matter of personal preference... if you like the stock look go for the drop-in. If you like an unique looking pipe under the hood and a little bit different (more powerful and slightly louder) sound of the engine, go for the CAI.

Daemon

[RIBEMR26]

How about dropping a K&N in the box, and then "debaffling" it to get the good sound? Maybe the best of both worlds?

[M3Daemon]

It might work to a certain degree, but I don't think it would be the same sound as with a CAI though. Most of the roaring sound is produced in the long intake pipe.

Daemon

[bimmer_boy]

The roaring sound is rather annoying.

I will state my opinion, which I've stated numerous times, one last time.

Drop a green filter in your stock airbox and get the 5-8 hp increase without spending 200-300 dollars and wasting the time on the installation. You will see the same increase in power as you will from a cai with a difference of possibly 2 hp. Most dyno tests I've seen put them virtually even. When comparing a cone style intake(not cai) to a drop in filter the drop is produced better results.

If you're willing to spend a few hundred on a "good looking pipe" rather than dropping in a $40.00 filter that will give you %99 of the same results with less hassle, than go for it.

[RIBEMR26]

I would tend to agree Bimmer Boy, thats why I asked. i'm kinda lazy, and if I can get the same, or almost the same results with less work (and in this case less $$$) then thats what I'll do.

[El Presidente]

A high quality drop in will yeild almost the same results, if not the exact same, for a fraction of the cost. The only reason to buy a a CAI is for the sound and look, but you can get similar gains from debaffling and a good drop in.

[M3Daemon]

I bought my CAI for $50... so cost is not really an issue.

Daemon

[El Presidente]

what filter came with it?

[CiscoKid]

a crappy one

[M3Daemon]

The whole system is made by Typhoon and they come with K&N filters. Check out this link.

... and CiscoKid... in your case I would stay away from long distance judgments, buddy... does not really add to the credibility of your statements.



Daemon

[camnipotent]

What CAI sis you get and will it fit in a 1998 323is?

[bimmer_boy]

Most cheap cai are made out of heat conducting material, rather than heat resistant.

What is the typhoon made out of and please show me a link to the page where it says it is $50.00.

Also, where does the cai exit the engine bay to take in it's cold air? Thanks.

[Autotechnica]

Originally posted by bimmer_boy@May 5 2004, 01:04 PM
The roaring sound is rather annoying.

I will state my opinion, which I've stated numerous times, one last time.

Drop a green filter in your stock airbox and get the 5-8 hp increase without spending 200-300 dollars and wasting the time on the installation. You will see the same increase in power as you will from a cai with a difference of possibly 2 hp. Most dyno tests I've seen put them virtually even. When comparing a cone style intake(not cai) to a drop in filter the drop is produced better results.

If you're willing to spend a few hundred on a "good looking pipe" rather than dropping in a $40.00 filter that will give you %99 of the same results with less hassle, than go for it.*

Ok.. here's the thing though. When you think about it, what's the point of having a CAI? It's to block off the heat produced by the engine and suck in cold air from the outside while the car is "moving". Which means, dyno plots mean squat. When you're on the dyno, the car isn't moving, there's no fresh source of air. So you would see almost no difference in an engine bay mounted cone filter vs. a CAI. In a real world test, such as a race track, there is a difference. I have a semi CAI where the filter is mounted in place of the stock horn. I also had a custom heat shield made. On the track and on the highway, it made a significant difference. I was using an engine mounted non-shielded cone filter previously. I've also used the K&N drop in for the stock airbox. None of these designs really work. The only one that does work is this.. mount a cone filter and angle it slightly towards the hole where the horn is mounted using a bent 3" pipe. Then have a custom heat shield made. Drive the car around for an hour and measure the temp. Hell just stick your hand into the engine bay, then stick your hand into the area where the heat shield is. If you've made a proper heat shield the area where the filter is should be relatively cool/warm, whereas the engine bay should remain hot.

Don't use a cone style filter without a heat shield, you're just sucking in lots of hot air which equates to power loss. The stock airbox design doesn't work too well either. It's too restrictive. The purpose of getting a cone filter is to have an "open" style filter so it can suck in more air. However, keep in mine in order to gain power you have to somehow make the air around the filter cooler than the air in the stock airbox.

If you're hardcore enough, go to a hardware store and purchase some aluminum flexable ducting for household A/C. Run this from the intake filter to the brake duct. This is a very common practice for people who track their cars, and it works!

Bry

[M3Daemon]

Originally posted by bimmer_boy@May 5 2004, 03:28 PM
Most cheap cai are made out of heat conducting material, rather than heat resistant.

What is the typhoon made out of and please show me a link to the page where it says it is $50.00.

Also, where does the cai exit the engine bay to take in it's cold air? Thanks.

I got mine of ebay. I am usually very suspicious about cheap offers like that, but I gave it a shot anyway and it turned out the product is good. The pipe is made out of aluminum. I realize it's not as good as CF, but I think the high velocity of the air stream, hence the short time it spends in the pipe, does not really permit to heat the air too much. The most crucial part is the place where you are getting the air from initially and I can only point to the post by Bry above, he is absolutely right, can't really add much to it.
And again... CF intakes might give you some slight bonus of keeping the air in the pipe cold but like I stated above the difference should not be significant. The only improvement I am planning for mine is the custom heatshield mentioned by Bry.

Daemon