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Discussion Starter #1 (Edited)
ok after looking at many threads I am leaning on a combination of a cone air filter combined with the AA/HD Ram air........
I don't believe anyone has tried this but sawing off the tip of the OEM outlet in the airbox and installing a 30 degree angular custom K&N cone filter.
http://www.ajusa.com/cgi-bin/knfilters/details?part_num=RC-4790&lookup=1&ajr_skey=3073c6f2325da312139db2e8461f98b2


The big drawback I see with the RAM air is that you are picking up a huge amount of dirt from the roads and water on rainy days..........maybe that is why BMW engineers strategically placed the OEM air ducts behind the bumper near the front vents facing sideways...

What do you guys think?
 

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Ive done a ram air style, A Dinan cold air intake, and the Active Autoworks intake. After all the different tries, Im back to the stock intake and airboxes with the stock filters. It feels stronger stock. The only time it felt better with the other intakes, was the ram style over 100 mph. I lost power for sure under 50mph.

josh.
 

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marcvip[size=4 said:
]The big drawback I see with the RAM air is that you are picking up a huge amount of dirt from the roads and water on rainy days..........maybe that is why BMW engineers strategically placed the OEM air ducts behind the bumper near the front vents facing sideways...[/size]



What do you guys think?
Marc I don't know what kind of performance it would add but if it's low enough to pick up water on rainy days I not sure I like that idea. This fall I had to replace an engine in a early 540i because it ran through some water that was not to deep (at least that's what the customer said). That was the third one I saw mainly because the intake tube for the air filter was to low. BMW has since raised the tube about 6 to 7 inches and that seemed to cure the problem. So I guess I'm kind of gun shy.

Joe
 

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I've done it! And am very happy with this setup! I've had it for over a year now! I took the K7N cone filter from the GruppeM and simply installed it in the OEM airbox!

And then connected the inlet to the Active Autowerkes RAM pipes! Its works fine!
 

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You will need to use a pointed cone filter like the one in this pic! AA flat nosed filter wont work very well in a confined space!

 

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Discussion Starter #6
hudson said:
Marc I don't know what kind of performance it would add but if it's low enough to pick up water on rainy days I not sure I like that idea. This fall I had to replace an engine in a early 540i because it ran through some water that was not to deep (at least that's what the customer said). That was the third one I saw mainly because the intake tube for the air filter was to low. BMW has since raised the tube about 6 to 7 inches and that seemed to cure the problem. So I guess I'm kind of gun shy.
Just like Ahmed I am thinking of placing the cone filter in the OEM airbox so no water would get in easily..........

ahmed said:
I've done it! And am very happy with this setup! I've had it for over a year now! I took the K7N cone filter from the GruppeM and simply installed it in the OEM airbox!

And then connected the inlet to the Active Autowerkes RAM pipes! Its works fine!
Don't you think too much dirt and water get in the AA ram kit since it is so low on the bumper? water entering the system can hurt the engine...
<!-- / message -->
 

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Discussion Starter #7
phillym5 said:
Ive done a ram air style, A Dinan cold air intake, and the Active Autoworks intake. After all the different tries, Im back to the stock intake and airboxes with the stock filters. It feels stronger stock. The only time it felt better with the other intakes, was the ram style over 100 mph. I lost power for sure under 50mph.
The combination seems to be the ideal HP option....
 

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marcvip said:
Just like Ahmed I am thinking of placing the cone filter in the OEM airbox so no water would get in easily..........
<!-- / message -->
If you keep the stock air box I think it would be fine. Ahmed's lives in a drier climate and he could get away with lower intake tubes. Living in the northeast US we get flash floods all the time so air intake is a consideration IMO.

Joe
 

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My BMW tech was able to combine the Dinan CAI system along with it's newly released air fog light ducts, and the Active Auto Werkes CAI system, combining the two systems to work as ONE ! Its the very best of both! Who says you can't have your cake & eat it too........................... ;)
 

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i'd have to look at my stock airboxes to be sure, but isn't there a velocity stack type of thing in the stock airbox that you'd have to cut off to mount the cone filter? I'd think that may cause some loss of airflow.
Mike
 

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I would avoid the KN at all costs. They simply flow more dirt as well as air. They do not have the surface area to filter enough and they flow large particles. Maybe look at ITG or another foam type filter. Gauze is fine if you are rebuilding motors on a regular basis. On my race car I don't use a filter because I rebuild after 50 Hours of use.

Ther is an independant lab test of KN verses factory and it it quite interesting to see the factory filter performance is very good for power and for keeping the dirt out. You don't want any large particulates geting past the filter and into the combustion chambers.

Here is a post from the M3 group:

I was
>responsible for evaluating re-usable air filters
>for a major construction/mining company that had
>hundreds of vehicles ranging from large earthmovers
>to pick-up trucks and salesmen's cars. This study
>was embarked upon due to the fact that we were
>spending upwards of $30,000 a MONTH on paper air
>filters. Using them one time then throwing them
>away.. I inititated the study in that I was convinced
>that a K&N type filter or oiled foam would save us
>many dollars per year in filter savings, man hour savings,
>and of course engines as these would filter
>dirt better than paper. (yes, I had read the K&N ads and was
>a believer)
>Representative test units were chosen to give us a
>broad spectrum from cars right through large front
>end loaders. With each unit we had a long history
>of oil analysis records so that changes would be
>trackable.
>Unfortunately, for me, every single unit having
>alternative re-usable air cleaners showed an immediate
>large jump in silicon (dirt) levels with corresponding
>major increases in wear metals. In one extreme
>case, a unit with a primary and secondary air cleaner,
>the secondary (small paper element) clogged
>before even one day's test run could be completed.
>This particular unit had a Cummins V-12 engine
>that had paper/paper one one bank and K&N/paper on
>the other bank; two completely independent
>induction systems. The conditions were EXACTLY
>duplicated for each bank yet the K&N allowed so
>much dirt to pass through that the small filter became
>clogged before lunch. The same outcome occured
>with oiled foams on this unit.
>>We discontinued the tests on the large pieces almost
>immediately but continued with service trucks,
>formen's vehicles, and my own company car. Analysis
>results continued showing markedly increased
>wear rates for all the vehicles, mine included.
>Test concluded, switched back to paper/glass and all
>vehicles showed reduction back to near original levels
>of both wear metals and dirt. I continued with
>the K&N on my company car out of stubborness and at
>85,000 miles the Chevy 305 V-8 wheezed its
>last breath. The top end was sanded badly; bottom
>end was just fine. End of test.
>I must stress that EVERYONE involved in this test
>was hoping that alternative filters would work as
>everyone was sick about pulling out a perfectly good
>$85 air cleaner and throwing 4 of them away
>each week per machine...
>So, I strongly suggest that depending upon an
>individual's long term plan for their vehicles they simply
>run an oil analysis at least once to see that the
>K&N or whatever alternative air filter is indeed working
>IN THAT APPLICATION... It depends on a person's priorities.
>If you want performance then indeed the K&N is the
>way to go but at what cost???
>And no, I do not work for a paper or glass air
>filter manufacturing company nor do I have any affiliation
>with anything directly or indirectly that could
>benefit George Morrison as a result..

Here's the info I have on air filter performance. Tests were done using
SAE J726C Test Method 5-best --> 1-worst

Oiled foam Paper Oil Bath Oiled
Gauze
(AMSOIL, UNI) (K&N)

Large particle efficiency 5 5 5 4
Small particle efficiency 5 4 1 2
Airflow capacity 5 2 3 5
Dust holding capacity 4 2 5 2
Load up characteristic 4 1 5 1
Backfire characteristic 3 2 5 3
Cleanability 4 1 4 3

As you can see, K&Ns are great for airflow, which is what they were
designed for. Their original application was on racing engines, where
airflow is important and ultimate engine life was of little consern.
They
are not as good at filtering as paper or oiled foam types.

Jordan
 

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jordantii said:
I would avoid the KN at all costs.
They
are not as good at filtering as paper or oiled foam types.

Jordan
This is why when I installed the AA CAI, I left the stock filters in. I just change them more regularly.

I Brand new Stock filter Flows the same as a K & N. But as the stock filter gets dirty, it flows less. So keep it new all the time.

However a K & N is supposed to get the same flow rate, but as it gets dirty, it is supposed to filter better, but too late. Its already let everything go, as well as oil to foul the MAF.

I ran a K & N in my 540, and thought all was fine.

After I sold it, the new owner after a few months , said it didn't seem like it performed as well as it did at first.

They discovered the Maf was fouled. They cleaned it and he was very happy with the increased Power.

I had never reoiled that K & N. It was brand new.

So, I have two K & N's sitting in my garage that will never go in. Its not worth the risk.

Especially when even K & N say that a NEW Stock filter flows fine. :cheers: They say, but quickly gets dirty and flow is reduced.

If it is quickly getting dirty, then it is WORKING. :D
 

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Discussion Starter #13
Those are all valid points......but K&N has been around for 35 years and I've seen cars go over 200k miles running on them.........a strong key to long engine life is changing the oil filter every 2500 Miles which is something most people don't do............no matter if you use a stock filter or K&N ~<1% of particles pass through........I've went as far as placing a magnetic belt around the "can" type oil filter on my P-car to help collect contaminants....


K&N said:
K&N filters are tested by an outside, independent laboratory, Southwest Research Institute in San Antonio, Tx. They have been proven to stop at least 99% of particles on a SAE dust test. This test uses a range of particles from the 0 - 5 micron range up to 20 microns. For comparison sake, a paper filter stops 99% on the same test and the OEM minimum standard is 96%. Foam is generally the worst media with a typical efficiency rating of 80 - 85%. To get higher ratings, the foam must be more dense and consequently more restrictive. The "tack" characteristic of a K&N allows for increased filtration without loss of airflow.


<!-- Item ID # 1225 -->The testing procedure used is SAE J-726 using ISO Test Dust. This test is the standard of the air filter industry. The test procedure consists of flowing air through the filter at a constant rate (airflow rate is determined by the application) while feeding test dust into the air stream at a rate of 1 gram per cubic meter of air. As the filter loads with dust the pressure drop across the filter is increased to maintain the prescribed airflow rate. The test is continued until the pressure drop increases 10" H2O above the initial restriction of the clean element (in this case .78" to 10.78" H2O). At this point the test is terminated. The dirty filter element is then weighed. This weight is compared to the clean element weight to determine the total Dust Capacity. The amount of dust retained by the filter is divided by the total amount of dust fed during the test to determine the Cumulative Efficiency.

<!-- Item ID # 1226 --><TABLE width=425 align=center border=1><TBODY><TR align=middle><TD colSpan=2>* The K&N filter achieved the following results:</TD></TR><TR align=middle><TD width="50%">Dust Capacity</TD><TD width="50%">305 Grams</TD></TR><TR align=middle><TD width="50%">K&N Cumulative Efficiency</TD><TD width="50%">99.05 %</TD></TR></TBODY></TABLE>

<!-- Item ID # 1227 -->*Links to the filtration tests are on the K&N web site at:

http://www.knfilters.com/images/factstab1.gif

http://www.knfilters.com/images/factstab2.gif

<!-- Item ID # 1228 -->So, what this proves is that you really cannot arrive at any intelligent conclusions by holding the filter to the light. That inspection is useless, pin holes are normal. In fact, those pin holes are what makes a K&N filter efficient. Within those holes, there are actually hundreds of microscopic fibers spanning them. When treated with oil, these fibers capture and hold the very fine particles. On the same hand, the fibers allow the filter to flow more air than paper or foam. Additionally, we have to understand that oiled fibers are translucent and are not easily visible to the naked eye. Spray some WD 40 on a sheet of white paper and you will see the effect. The K&N filter is four-ply cotton gauze unlike some competitors synthetic material filters. The synthetic material filters do not have the very small fibers that natural cotton does. Also, the oil in a K&N is completely absorbed into the media and there is no risk of contaminating electronic sensors as there is with Foam filters that can have oil pulled from the soaked media.

<!-- Item ID # 1229 -->K&N got started over 30 years ago making filters for motorcycles and off road racers. The filters did so well that these customers wanted similar filters for their cars and trucks. K&N started making filters for these applications and here we are today making filters for just about any application on the market. If our filters did not work, we would not be in business growing every year.

<!-- Item ID # 1230 -->K&N makes filters for Chrysler/Mopar, Ford Motorsports, Edelbrock, Rotax Engines, and Harley Davidson. K&N filters come as original equipment on the 2000 Ford Mustang Cobra-R. K&N even made filters for the Apache helicopters used in Desert Storm because of maintenance problems with the original paper design. If K&N filters work in these conditions they will work for you.



Thanks, Rick Blum
Technical Support Supervisor, K&N Engineering
 

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marcvip said:
Those are all valid points......but K&N has been around for 35 years and I've seen cars go over 200k miles running on them.........a strong key to long engine life is changing the oil filter every 2500 Miles which is something most people don't do............no matter if you use a stock filter or K&N ~<1% of particles pass through........I've went as far as placing a magnetic belt around the "can" type oil filter on my P-car to help collect contaminants....




Hey Marcvip,

I ran the K & N on my HSV (OZ Chevy) for 3 years with no problems.

But that doesn't really say anything. My concern is, the risk is much greater than the small (possible) reward.

This is one of the few times, I have erred on the side of caution.

Dinan did a test and dynoed with the Greatest CAI of all, NONE.

Just to prove how much HP was on the table up for grabs.

From memory it was like 11 or 12 HP.

In otherwords, any filter will be less than that. I think they did 5 HP for CAI and 6 for Mafs or something.

But basically, there were no Real gains to be had.

Thats why I decided not to mess with the Stock setup.

I liked the way the AA CAI adds to the stock setup. But I didn't use the two K & N's provided.

There is a releif hole to prevent water ingestion.

Even if you submerged the whole nose of the car (Egg Ring)under water, the AA CAI would not suck water.

So it is safe.

MJ
 

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Discussion Starter #15
MIB said:
There is a releif hole to prevent water ingestion.

Even if you submerged the whole nose of the car (Egg Ring)under water, the AA CAI would not suck water.
Where is it and how does it work?
 

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marcvip said:
Where is it and how does it work?
The hole is up very close to the Stock Filter box.

If the two egg rings were blocked, the motor would such air from the least point of resistence, thus these holes.

For these holes to go under water, The stock system would be under water, and you'd be screwed anyway.

Have you ever tried using a straw that had a split in it? Same deal. You start sucking air from the top instead of liquid from the bottom.
 

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The report from KN is to keep people at ease with the use of their product. They use an independant lab, yes, but the evidence is in their favor. There have been many tests done thet are not in their favor. The power yield is not significant enough to warrant the risk IMO.

Do as you wish.....

Jordan
 

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jordantii said:
The report from KN is to keep people at ease with the use of their product. They use an independant lab, yes, but the evidence is in their favor. There have been many tests done thet are not in their favor. The power yield is not significant enough to warrant the risk IMO.

Do as you wish.....

Jordan
Same old story- Why no comparison to factory filters? I always like the anecdote that someone got 200k miles on a chevy, ford, dodge.....etc

I had a grandfather who smoked until he was hit by a car at 105 years of age... does this mean smoking is safe? Evidently....

With so many car parts, the criteria for race cars is so differnet from daily drivers... many mfgs market based on their race programs to justify the use on any auto application. Oils, filter, etc.

Kind of like arguing religion though...

A


PS 99.05% cumulative efficiency with 305 retained grams means that it let 3 grams of dirt into the engine.... compared to??? what
 

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ard said:
Same old story- Why no comparison to factory filters? I always like the anecdote that someone got 200k miles on a chevy, ford, dodge.....etc

I had a grandfather who smoked until he was hit by a car at 105 years of age... does this mean smoking is safe? Evidently....
Hey Ard,

My favourite was this,

Fact : Some people who do not smoke, get lung cancer.

Fact : Some people who do smoke, do not get lung cancer.

(Conclusion) Therefore Smoking does not cause, Lung Cancer. hmmm

Its what's called two correct Facts, with a wrong conclusion.

Maybe the people who did not smoke, got lung cancer from inhaling second hand smoke.
 

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pictures please.

emperor
:M5rev: :M5launch:


FAST 5 said:
My BMW tech was able to combine the Dinan CAI system along with it's newly released air fog light ducts, and the Active Auto Werkes CAI system, combining the two systems to work as ONE ! Its the very best of both! Who says you can't have your cake & eat it too........................... ;)
 
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