Performance air filters necessary? [Archive] - SaabCentral Forums

: Performance air filters necessary?


bkrell
02-07-07, 10:05 AM
Practically all the tuners state that you need a "free-flowing" filter setup with a foam or K&N style filter media. Has anyone seen any dyno testing on 900/9-3's showing before/after where just the filter is changed? Is it getting rid of the restrictive piping of the stock box that really makes the difference? Just curious as I was just reading a test posted on bitog. This test is old, I just never bothered to read it as the results trickled into bitog lure along time ago-mainly don't bother with a K&N.

http://www.bobistheoilguy.com/airfilter/airtest1.htm

ragtopcav
02-07-07, 10:22 AM
One of the parts suppliers refuses to honour the warranty of APC solenoids if you use 'free flowing' filters.

Some guys have done inlet work with dyno testing; one school of though is that stock is good for 300+ bhp.

Saabohème
02-07-07, 11:22 AM
That online tuning site (sort of an online tuning magazine), whose name eludes me, did a very thorough and scientific study of the entire intake tracts of a few cars, measuring the pressure drops over all of the various areas and transition points in the intake tract. The inescapable conclusion was that the stock paper filter is NOT a culprit in creating restriction in the tract. The pressure drops measured across the paper filter media were negligible. Restated: Changing from a paper filter element to a gauze or foam element, ALL other things being equal, will yield an extremely small difference in performance.
When you factor this in with the increase in the amount of silica the the other media can allow to pass, the cost of the fancy intake piping and filter, the fact that most do not amount to a true cold air intake because they place the set up in such a way that it must inhale engine heated air, and the fact that the loss of the intake trumpet will often result in the loss of a noticeable amount low-end torque, you find yourself wondering why you would even consider one.
The answers are: 1) They look real nice, 2) they sound real mean, and 3) they do last a lifetime so at least they have the potential to defray the purchase price.
There is still some persistent apocrypha out there that performance gauze and/or foam open intake filters will flow significantly more air at higher rpms than stock intake tracts using paper filters. These claims are never accompanied by any independently performed side by side comparisons to stock intake set-ups, and to the extent that they ARE in fact true (and some of them are), the difference would be most attributable to such things as the diameter of the intake trumpet and not the nature of the filter media itself (if the results of the independent study first mentioned herein have any credibility at all, and I think they do).

9-3sleeper
02-07-07, 03:09 PM
The advantage of a K&N is that they last for the lifetime of the car, you don't replace them, just clean them, however they do offer slightly better flow than paper air filters and still filter just as good, if you aren't into extreme perfomance and looks and sound, just buy a drop in K&N for your stock airbox. Iv'e seen tests done with both paper and K&N filters, they def. flow better, which is never a bad thing.

stromer
02-07-07, 03:21 PM
One of the parts suppliers refuses to honour the warranty of APC solenoids if you use 'free flowing' filters.

This is becoming more and more common from what I have heard. The extra flow allows more dust particles in that can clog up the solenoids. That being said, I still run a K&N filter.

9-3sleeper
02-07-07, 03:25 PM
As do I, for more than a year now, with no issues.

Saabohème
02-07-07, 04:45 PM
The advantage of a K&N is that they last for the lifetime of the car, you don't replace them, just clean them, however they do offer slightly better flow than paper air filters and still filter just as good, if you aren't into extreme perfomance and looks and sound, just buy a drop in K&N for your stock airbox. Iv'e seen tests done with both paper and K&N filters, they def. flow better, which is never a bad thing.
I stand by this: There is still some persistent apocrypha out there that performance gauze and/or foam open intake filters will flow significantly more air at higher rpms than stock intake tracts using paper filters. These claims are never accompanied by any independently performed side by side comparisons to stock intake set-ups, and to the extent that they ARE in fact true (and some of them are), the difference would be most attributable to such things as the diameter of the intake trumpet and not the nature of the filter media itself (if the results of the independent study first mentioned herein have any credibility at all, and I think they do). If you can cite or link me to reliable independent studies supporting that any one medium is significantly superior flowing to any other one, under identical setups and conditions (i.e. in the same housings and locations) then I will revisit my thinking. BTW - I use a JR, (without delusion), mainly because I like the way it looks and sounds, not for any purported performance gain. I let it get dirty and stay dirty, as that increases its filtration capability (efficacy). I clean and re-oil about every 18 mos. to 2 years.

9-3sleeper
02-07-07, 05:04 PM
I cant give you an address to find it at because it was a display I saw in person, it was composed of one chamber made of transparent plastic, and was totally air tight except for an intake for a small fan, and a tube that housed a ping pong ball inside it. There was also a door you could open to istall an air filter into, with both a K&N and a regular paper filter to choose from. With the paper filter in, the ball could only rise to a certain point iside the tube, with no filter, the ball raised even more, and once the K&N went in, the ball rose to the same level as with no filter at all, proving that in exactly the same environment, the K&N allowed for more air to pass through it. I'm not saying that this will be a huge boost in power, but it will allow for your engine to suck air in a little bit easier.

Vigge
02-07-07, 05:41 PM
I cant give you an address to find it at because it was a display I saw in person, it was composed of one chamber made of transparent plastic, and was totally air tight except for an intake for a small fan, and a tube that housed a ping pong ball inside it. There was also a door you could open to istall an air filter into, with both a K&N and a regular paper filter to choose from. With the paper filter in, the ball could only rise to a certain point iside the tube, with no filter, the ball raised even more, and once the K&N went in, the ball rose to the same level as with no filter at all, proving that in exactly the same environment, the K&N allowed for more air to pass through it. I'm not saying that this will be a huge boost in power, but it will allow for your engine to suck air in a little bit easier.
marketing wonders which have very very very very little to do with reality...

a few test to read through

Tests which I have carried out under the past few years, regarding the topic of filters and intake

most recent
http://www.stcf.net/filter/Filter_comparison_II.htm (http://www.stcf.net/filter/Filter_comparison_II.htm)
same but older and with no so sophisticated measurement tools
http://www.stcf.net/intake/Filter_comparison.htm
9-3 intake pressure study
http://www.stcf.net/intake/

and what comes to costs the price of one K&N buys you like 10 std filters.

9-3sleeper
03-07-07, 02:02 AM
Well, I'll stick with mine.

pade900
03-07-07, 02:23 AM
The advantage of a K&N is that they last for the lifetime of the car, you don't replace them, just clean them, however they do offer slightly better flow than paper air filters and still filter just as good, if you aren't into extreme perfomance and looks and sound, just buy a drop in K&N for your stock airbox. Iv'e seen tests done with both paper and K&N filters, they def. flow better, which is never a bad thing.

I would love to see some data on this one :)
I find it VERY hard to believe that a K&N (or similar) sports filter would filter just as good as a filter made out of paper. One doesn't need to be a rocket scientist to hear some warning bells ringing here:roll:

Anyway, if someone is willing to risk the MAF and possibly other components and have the car suck in much hotter air than with the stock box just to make the car sound cool then hey, what the hell.

Personally I like to listen to people who has actually done some serious testing and have some data to provide and not just a statement that "the car really spools quicker and has a noticable gain in low-end torque since the installation of my K&N", the old mighty butt-dyno isn't all that reliable :D

If there is no noticable difference between an open air filter (K&N) and the stock paper filter in the stock box on a +400hp car then I don't see the point.
It has also been tested that removing the entire air box and filter, ie. turbo sucking air directly to the compressor, did not prove any significant increase in power, this also on a +400hp car.

But yes, the sound will change:lol:

9-3sleeper
03-07-07, 02:33 AM
One doesn't need to be a rocket scientist to hear some warning bells ringing here:roll:


Just what in the hell are you implying? Because this sounds like you have something against me just as much as against performance filters. Also, I've had my oil filter for more than a year, and my MAF has never had any issues with it, maybe it's just because some people don't know how to re-oil them after cleaning so they put gobs upon gobs of oil on it? As with anything else, excess is usually bad.

pade900
03-07-07, 02:35 AM
Just what in the hell are you implying? Because this sounds like you have something against me just as much as against performance filters. Also, I've had my oil filter for more than a year, and my MAF has never had any issues with it, maybe it's just because some people don't know how to re-oil them after cleaning so they put gobs upon gobs of oil on it? As with anything else, excess is usually bad.

Nothing against you or performance filters when and if they really are needed.
Just trying to point out that all marketing schemes should perhaps not be swallowed without chewing.

9-3sleeper
03-07-07, 02:37 AM
Ok, thats understandable. Try to be a little less offensive with the sarcasm if at all possible.

pade900
03-07-07, 02:48 AM
Ok, thats understandable. Try to be a little less offensive with the sarcasm if at all possible.

Sorry about that.
I'm from Finland and English is not my mother tongue so i guess my "tone" can be missunderstood at times when writing in English.

9-3sleeper
03-07-07, 03:00 AM
Oh, well then I'm sorry as well, I can definatly understand a language barrier, one of my very good friends is from Hungary. Don't worry about it man, I'm getting too tired tonight, it's almost 3 here, sorry for being grumpy.

Saabohème
03-07-07, 06:49 AM
Sorry about that.
I'm from Finland and English is not my mother tongue so i guess my "tone" can be missunderstood at times when writing in English.
Your grasp of English is superb. You write extremely well. "Tone" and nuance are often lost in writing, but this is not due to any language barrier. It is just the nature of the beast. Satire, and wry tongue-in-cheek humor are usually among the first victims. It is commendable that everyone can respectfully agree to disagree.

boxman
03-07-07, 08:15 AM
speaking from experience when i fitted my itg it made no difference at all, i have since modded a little further as to what the difference is now i haven't tried fitting a stock air filter in to see

Ryans900se
03-07-07, 10:27 AM
I have a K&N drop in filter and theres no noticable difference to me, other than I can say I have a K&N filter.... OH AH.

//out some money:(

Saabohème
03-07-07, 12:15 PM
I have a K&N drop in filter and theres no noticable difference to me, other than I can say I have a K&N filter.... OH AH.

//out some money:(
But it looks MAHVELOUS. And sounds good too. So, what the hay.

Ryans900se
03-07-07, 12:18 PM
But it looks MAHVELOUS. And sounds good too. So, what the hay.

Nope cant even tell I have one. It's the panel filter you drop in the box :)

Saabohème
03-07-07, 02:46 PM
Nope cant even tell I have one. It's the panel filter you drop in the box :)
But when you pop the top on your air box, THEN it LOOKS MAHVELOUS. AND, (thats right), AND, since you bought the panel filter, you did not shell out lots of extra for the intake pipe and ersatz heat shield. SO, your filter will pay for itself in just a few years AND then, you can trash it if you want OR you can sell it on ebay. OR, you can sell it on ebay right now OR just toss it OR keep it FOREVER. YOU HAVE OPTIONS. AND they look MAHVELOUS.

Ryans900se
03-07-07, 02:47 PM
But when you pop the top on your air box, THEN it LOOKS MAHVELOUS. AND, (thats right), AND, since you bought the panel filter, you did not shell out lots of extra for the intake pipe and ersatz heat shield. SO, your filter will pay for itself in just a few years AND then, you can trash it if you want OR you can sell it on ebay. OR, you can sell it on ebay right now OR just toss it OR keep it FOREVER. YOU HAVE OPTIONS. AND they look MAHVELOUS.

I like you:cheesy: :cheesy: :cheesy:

boxman
03-07-07, 03:14 PM
well that said it does look good when you lift the bonnet and there is a label saying DO NOT THOUGH AWAY but that could just be cus i'm tight :roll: