Another Expert Says "NO" to K & N

I have for a long time (after doing research on the matter) rallied against the use of K&N air filters on Porsches. Why? Because based on Bruce Anderson's dyno tests on various 911s, they don't produce any more hp than the stock filter (while it is true that a new K&N may "flow" more air than a stock filter, such increased flow is meaningless because the filter is not the bottleneck in the system). Plus, based on K & N's own numbers, they let A LOT more dirt into your engine. So, you get to wear your engine out faster for no reason at all.

Jim Conforti is a BMW god, kind of like Bruce Anderson is to Porsche. Below is an account that was posted on a BMW board recently (it was not posted by me), which involves Conforti's testing of K & N filters.

Of course, with your own car, you should do what you think is best, but I'd be careful about the advertising hype of K&N, and I personally would not use one of those in my babies.
__________________________

"As I mentioned in an earlier post, this past Saturday was the BMWCCA NY Chapter's annual meeting & "Beach Party". It was held at EuroMeccanica in Mount Vernon, NY and I'd estimate there were aproximately 75 members present when it was the fullest. There was a wide range of owners including M6s, M3's (E30 & E36), 6 series, 5 series, 3 series, Z series, and 7 series. Someone even mentioned an '02 but I don't know if he owned one.

The day started with Mike Schiffer (owner/proprietor of EuroMeccanica) doing a teardown of a carburated I6 BMW engine. For those that had never seen this it gave an nice overview of how an engine works.

Next came lunch followed by a brief session of chapter business.

Jim Conforti gave a short talk followed by a rather informative (and long) Q/A session. If you've never had the opportunity to hear Jim speak you should try to catch him if he ever comes by your area. Jim's session started running long (*everyone* had questions and Jim had good answers that kept us all attentive) and the group split in two: One remained with Jim while the other followed Josh Collins (owner/proprieter of Eurosport) to do a demonstation of an Intake & Chip in an E36.

I remained in the Q/A with Jim and learned quite a bit:

Jim discussed intakes, filters, and why they decided NOT to use K&N filters on their intakes. The discussion that appeared here (and in many other forums) about these filters allowing more dirt through came from Jim's testing in a proper lab designed for just this purpose. He mentioned that the data supporting this can be found on his web site but I was not able to find it (yet). In summary: Initially, the K&N does flow better than stock paper but also allows 500% more contaminants through. Since the filter has lower surface area than stock it also clogs much quicker and results in much lower airflow than the original stock in a shorter amount of time."

_________________________________

Thought I would ask K&N to comment, here is what they said....

Neil

Dear customer,
I would have to say this person is not much of an "expert". Our filters
are tested by an outside, independent laboratory. They stop 97 % of
particles on a SAE fine dust test. This test uses mostly particles in the 0
- 5 micron range but goes up to 20 microns. For comparison, a paper filter
stops 98% on the same test and the OEM minimum standard is only 95%. We got
started over 30 years ago making filters for motorcycles and off road racers
(the Baja 1000 was what got us started). The filters did so good that these
guys wanted them for their cars and trucks. We started doing this and here
we are today. If they did not work, we would not still be here and growing
every year. We now make filters for Chrysler/Mopar, Ford Motorsports and
Harley Davidson. We will come as original equipment on the 2000 Ford
Mustang Cobra-R. We even made the filters used in the Apache helicopters
used in Desert Storm and the US Marine Corps new Osprey tilt-rotor aircraft.
If they work in these conditions they will work for you.
Thanks for asking, Rick

I'm very surprised that KN would say such things! Go figure.

I wonder what Splitfire, Slick 50, etc. say about their own products . . .

Brian

[This message has been edited by Brian Kumamoto (edited 02-12-2000).]

I am with you Brian ,if the K&N technology was so superior we would have seen filters progress to their technology years ago, also why don't they have more competition with their technology if its so great.
Whats great is their advertising firm with the hype of the promise of a easy HP gain with BS stats behind them

If I am not mistaken, the only production vehicle in the Chrysler lineup using K&N is the Dakota R/T 5.9, and those drag-racer types it appeals to are not quite as reliability concerned as the average customer, and as far as Mopar Performance parts go, they carry NO WARRANTY, and are intended for 'off-raod use' ONLY!!! I would be very interested to see what kind of warranty K&N offers? Fram has a statement on the side of every box: 'Warranty: AlliedSignal's Fram Air [Oil] Filters are warranted against defects in design, materials and workmanship. New vehicle warranties remain in effect when Fram Air [Oil] Filters are installed according to Fram directions and replaced at least as often as vehicle manufacturer's recommended change intervals.'

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Warren Hall
1973 911S Targa

http://knfilters.com
http://knfilters.************************/

Here are two sites about K&N. More than you ever wanted to know, probably. What I am wondering is how truthful all of what they say is.

Paul

In my case I have Weber carbs. Since K & N is the only filter available (other than OEM and they are too ugly for words).
I'm stuck with them. A recent purchase of Wolferts air cleaners (made for the K&N element) makes my commitment even greater.

Who is right or wrong in this debate is,to me, moot. You pays your money and you takes your chances. Hype from both sides is over done.
J P Stein

So we would expect K&N to support their product, but where is the mysterious expert's alledged data??

I could put anything I wanted on a web site (or in a bulletin post)claiming it was a fact, but is it really?

1. I'm sure Jim Conforti would make his data available, if he did not do so at the meeting which was described in my post. With things like this, unless you have the time, ability and inclination, you kinda have to pick and choose who you trust. Conorti is in that category, for me.

2. Others, including Bruce Anderson, have shown that KN and other freeflow filters make no differnce on various 911s, including SCs and Carreras. On those cars, the airfilter is not the bottleneck, its the terrible exhaust. Therefore, there is no gain, even running with no air filter at all. So, why not just use the factory filter, which, by KN's own admission, does a better job of filtering.

3. KN admits that in their own tests, the paper filter only lets 2% of particles in, while the KN lets 3% in. By my math, this is a 50% increase in particulates that get into your engine, using KN's own test data cited above.

4. KN long lost credibility with me with their ads suggesting 20+ hp gains.

Bottom line: To me, KN is the anwswer to a question that no one has asked.

Last summer, I bolted on the PowerFlow intake kit. I wasn't sure if there was any improvement in performance. In addition, the increase in engine noise caused me to subconciously drive around at lower revs. Now I see that Excellence has published dyno results which refute their claims! They could not find any increase in HP! As these tests were done on a 996, I am wondering if anyone has experience with the PowerFlow from Zuck-Z on the 993?
Thanks

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Paul

Hi guys:

At the risk of trying to have the final word again, I must inform you that I saw Bruce Andeson at the Daytona 24 Hours, and upon questioning, he admits that he has revised a number of previous OBSERVATIONS (never opinions) about what works and what doesn't. One of those observations had to do with Dilivar studs (which he now recommends against, since his OBSERVATION is that they do not perform as they were intended). They in factm, stretch and break.

Once you meet this man, and come to understand his background and total committment to Porsches (he used to own a Porsche cusotmer shop and race shop in Mountian View, and wrenched for Bob Garrettson, one of the most successful Porsche privateers), you will come to respect his opinions. His book, "911 Performance Handbook" is going to its second printing, and will have the new information in it.

I also have found the K&N to have no appreciable HP gain; when we did my dyno tests on my 911SC, the 1974 headers were good for 20 HP PEAK vs the stock SC headers, and the K&N filters were good for 0 HP vs the stock air filters. Note that the HP gain was the peak, at only one particular RPM. This is the way things work, unless you have variable-tuned intake manifolds, like the new 911.

So, I think that someone like Bruce Anderson is more to be trusted than are advertising statements from the manufacturer. At least Bruce changes his mind when new information is presented to him. But so far, no new information has been presented by K&N or any testing data. Subjective opinions will never replace objective testing!!!!......Andras

K&N bashing? Sure, why not: Those guys at K&N must be nuts. A screen covered with oil? No way. Keep the OEM air filter system. Even you guys with old Porsches, keep your oil bath with wire screens. Yea, that's gonna work.

Darn:

I didn't get the last word on this "thorny" "dusty" subject.....Andras

Hi,

not the last word yet. I have been away, but have had further correspondence with K&N. I will post their email when I get home tonight (New Zealand time!!)

regards

Neil

So here is their last info....


Here are some more facts. The guy talking
about the Mopar filters is wrong too. We make 32 different OEM replacement
filters for them, 3 cold air intake kits, and our filter and exhaust system
is stock on the Shelby Durango R/T. They have asked us just last week for
the go ahead with proving these items as dealer installed options rather
than only after purchase upgrades which they are currently. We have
provided them with extensive flow and filtration data done on each part# and
they are totally pleased with them. The drop-in filters are noted in the
Mopar catalog as "Direct Replacements" and the kits are noted as "50 State
Emissions Legal". No where does it say "Off Road Use". Our warranty is the
exact same as what he says about the Allied Fram filters. They will not
void any factory warranties when used as directed. As for the guy who says
they clog more easily than paper is also incorrect. A K&N filter lasts as
long as 2 paper filters before needing service and even at this point it
still out flows a new paper filter. The reason we have not become more
popular with the OEM manufacturers is that they have deep pocket deals with
Fram and AC Delco to make their own brand of filters. This is beginning to
change however as they find out the you can no longer do business as usual
and stay competitive. The consumer wants choices. Thanks again, Rick

OK, whoooooopieeeee, they have a grand total of 3, count 'em, 3 limited production applications on Chrysler products, the three R/T Dodge trucks, and one limited production Ford! And, I never said K&N didn't have a warranty, what I meant was just that the items in the Mopar Performance catalog do not carry a warranty from Chrysler, due to the 'off-road' nature of the entire catalog!

I would be very interested to know who this 'Rick' is at K&N, a public affairs type? What are his credentials? Or, do ad-copy writers need credentials? I would also be interested in hearing K&N address the issue of drivability problems on Motronic-controlled 1984-89 Carreras, which is what sparked this thread in the first place?

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Warren Hall
1973 911S Targa

Whist some may feel this subject is already played out, i remain very interested. Not just because of the controversity but because potentially a $40 investment to boost the power of your engine by 5 - 10% could end up costing you a $7000 rebuild. recently the salesman at a major porsche parts reseller said the following to me when i ordered a K & N filter. " are you sure you really want one of those, i've yet to see anyone actually get a measured performance increase from one of these. the supposed 10 HP gain, is just snake oil & slick advertising if you ask me."
i went to the K&N web site to do a little more research & here's what i found.

SELECTED TEXT FROM K & N's WEB SITE

Installing a K&N Filtercharger in place of a original equipment or aftermarket paper filter removes the restriction which then allows the engine to inhale all of the air it can physically use. Increasing the amount of air available to the engine promotes performance since oxygen in the air is a necessary ingredient for combustion. If you have a computer controlled fuel injected car, the computer will automatically add the right amount of fuel to compensate for the additional air. If your engine is carbureted, more often than not, no adjustment will be necessary. However, for competitive motorsport, it may be necessary to re-calibrate the carburetor to achieve optimum performance.
The amount of performance gain varies from vehicle to vehicle. A small displacement four cylinder engine may only realize a two or three horsepower gain while it isn't uncommon for a 350 cubic inch V-8 to gain 10 horsepower or more. The greater the restriction created by the stock paper element, the greater the performance gain when you switch to a K&N filter

FROM ANOTHER PART OF THE WEB SITE

Horsepower
Using the proper size K&N air filter, no loss in horsepower is noticed and in some cases the horsepower actually increases over no filter at all.

SNAKE OIL?

The dirt particles collected on the surface of a K&N element have very little effect on air flow because there are no small holes to clog. Particles are stopped by crisscrossed cotton fibers and held in suspension by the oil. As the filter begins to collect debris, an additional form of filter action begins to take place because air must first pass through the dirt particles trapped on the surface. That means the filtration efficiency of a K&N element actually increase as the filter collects dirt. Tests have shown a K&N E-1500 filter will flow 60 percent of its maximum flow capacity after 50,000 miles of street use. And, considering a new K&N flows half again as much air as a comparable paper element, that same filter will provide all of the air the engine needs even after 50,000 miles.

OVERALL

the actual K & N site 'implies' that you get super duper increased performance but is pretty careful not to claim it.
the main thrust seems to be " we allow in more air efficiently over a longer period of time"
the customer/reader is lead to believe that that equals more HP. Its kinda stated in a roundabout way.
Whats it mean? Well to me - i wuld rather trust a Conti or an Anderson as these guys have nothing to gain.
i guess being a GURU in the motor industry is a tough job, you can lose money a thousand times but you cab only lose your reputation once.

Pazz and all of you:

As the ancient Romans once said (and it was probably based on experience) "CAVEAT EMPTOR".

or

"You pays your money and you takes your chances"

Now, can this be the last word?????...Andras

I found Rick at their "tech questions" email address.

Not only should the "buyer beware" but as someone with an economics background, I always like,"there are no free lunches".

I have enjoyed the discussion, I love the fact that you all have such a passion for Porsche!!!

I am looking forward to the next topic.

regards

Neil

New Zealand, Home of the Americas Cup (but for how much longer??)

I'm finding all this very upsetting.
I've been using K&N for about 15,000
miles on my 83SC.This is the first
I've heard that the filter wasn't
measuring up.The Bruce Anderson
info was the most meaningful, how
bad is it for a really babied
car ?