K&N Filter - Opinions?

[Don Plumley]

My '87 Carrera has a K&N Air Filter courtesy of the PO. (I posted a story on the Rennlist about how I put too much oil on it, caused a "leak", made me tear my hair out).

Anyway, what is your opinion of the K&N versus OEM air filter in my model? I've heard good and bad, so I'm trying to develop a concensus from the crowd.

Thanks in advance!

Don

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don@plumley.org
Das Zoom - '87 Carrera

[mideastmafia]

if the K&N was better, then the engineers at porsche would have put that on rather than the stock one. i dont think noise would have been a problem in a 911.


SHAUN

[island911]

search the past threads on this. Use key words; K&N, and snake oil.

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'81 Platinum Metalic SC COUPE

[movin]

You can contact K&N for verification of filtering capability. Testing per ASTM, independant testing lab. I did and the results are very comparable to the OEM paper filter. One thing to keep in mind is this media works best after proper oiling and interestingly, some accumulation of dirt. You can look into the Mass-Airflow Box and the rubber boot on the throttle body, wipe the insides with a clean white rag, if you don't see any grime then the K&N filter is doing its job. ONE THING MORE, I'VE NOTICED THAT ON MANY '84 THRU '87 THE LOWER LATCH CATCH/LIP ON THE BACK OF THE AIR BOX IS BROKEN OFF, PROBABLY DUE TO AGE & HEAT. I'M REFERING TO THE PORTION THAT IS BOLTED TO THE MASS-AIRFLOW BOX. CHECK THIS OUT, IT'S HARD TO ASCERTAIN BECAUSE OF LIMITED ACCESSABILITY. IF IT'S BROKEN, IT'S NOT LATCHING TIGHTLY AND WILL ALLOW UNFILTERED AIR INTO YOUR INTAKE TRACK REGARDLESS OF WHAT FILTER YOU USE!

[N11Porsche]

This subject has been discussed in detail. Do a search. I had a K&N on my 911, after installing it I read an article by Bruce Anderson in Excellence. He did dyno test with a K&N, factory filter & no filter. The factory filter gave slightly more h.p. than the K&N and filters better. His opinion: save your money and stick with the factory filter. Mine is for sale if your not convinced!

http://www.pelicanparts.com/pmpre/images/N11Porsche/P-Car2.jpg

Bill Carcot
1979 911SC
Diablo Region, P.C.A.

[Joeaksa]

Don,

I replaced my stock filter with a K&N clone (MSDS) and am very happy. Personally I do not care one bit about the noise or HP increase (get real, an air filter is not going to give you much!) but the old housing made it impossible to get to anything in the right rear part of the motor.

As well, a previous poster mentioned the bottom rear latch, which is impossible for anyone but a dwarf with four foot arms, so its a welcome mod for me.

just my 2c worth...

JA

[movin]

That's right, using the K&N cone filters allows you to bolt on a variety of inlet configurations, eliminating the air box, giving you more room for maintenance. I'm using the one that has a 90 degree turn and is shaped like an intake port. The design packs in more air, like a velocity stack, at high flow, and it does work. Only consideration is rain or water can get to the filter but it hasn't become a problem yet.

[Doug Zielke]

K&N filters don't belong on *any* motor you expect a long life from. They pass more dirt through than the OEM Porsche filter, even with the silly oiling ritual they require.
You can prove this with a trip on a dirty road, and a paper towel wiped inside the airbox.
While they may make more power on some engines, they make f***all in a properly maintained Porsche. It has been documented by the experts mentioned in other posts.

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'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
The Blue Bomber's Website

[MarkY]

Mr. Doug:

How right you are. Couldn't of said it better.

K&N - for Kooks and Nuts

[chuckr]

I use a K&N on my 83SC.I also have a Bursch cat by-pass and muffler.My dyno numbers are 183HP and 181lb/ft. I do admit that the K&N does not do well on some Porsches, the guys that run the Dyno shop said some cars loose
HP with the K&N.I my case,my numbers speak for themselves.I think any mod should have the dyno numbers to back it up,how else can you tell if it is snake oil or not ?

[twin plugged targa]

Doug, you may want to concider modifying that statement(*any* motor)to to be more accurate as....
Caterpillar and just about every other Marine Diesel installation I hav seen in the past 16 years have fitted K&N from new!.
The grey area with K&N is that they must be maintained properley, cleaned correctly and oiled correctly with the correct oil.
Everyone has their personal preference.
I concidered refitting my stock box, then saw the broken clip and remembered the size of it and flashbacks of swearing over grazed knuckles!.
I'm a K&N fan!
rgds Ben

[Doug Zielke]

Final comments: Oiled properly or not, K&N filters pass more dirt than OEM paper filters. The power advantages range from slight to nil, highly dependant on OEM filter design. (If you want a sure power increase, remove the filter entirely!)

So, tell us about it when you find the cylinders of your car, m/c....or "Caterpillar" diesel wear out prematurely.

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'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
The Blue Bomber's Website

[This message has been edited by Doug Zielke (edited 07-01-2001).]

[Jim T]

K&N is VERY good . . . .
at marketing.

[movin]

I was taking flight lessons a few years ago and the Cessena 172 I flew had a K&N air filter! Obviously the FAA has evaluated this product to a much higher qualitative standard than any of us are capable and found it acceptable. I have used K&N in my Ranger truck for 250,000mi, my wife's Corvette for 140,000mi and the intake tract has always been superbly clean. I suspect that some aftermarket applications may be using an undersized filter where the suction can overcome the filter's ability to hold onto particles allowing passage into the intake.
On another note, I think the reason most of us use K&N is not for some imaged power gain but for the welcomed additional room and cost savings, ($250 to replace the airbox and the savings that accumulate by not having to buy a new $25+ paper filter periodically).

[This message has been edited by movin (edited 07-01-2001).]

[This message has been edited by movin (edited 07-01-2001).]

[This message has been edited by movin (edited 07-01-2001).]

[This message has been edited by movin (edited 07-01-2001).]

[movin]

Just corrected some spelling.

[This message has been edited by movin (edited 07-01-2001).]

[twin plugged targa]

Cars aside, as I said before Caterpillare install as their stock filter K&N, they Warrantee their engines with K&N.
We use fairly small engines but at 1,350 HP they suck a fair amount of air.
I don't think these engines manufacturers would risk reccomending and installing sub standard filters on a $120,000 engine!.
I am sure there are so many variants as to the application of useage (dusty/dry/wet)and maintenance (frequent/infrequent/never!)that it is difficult to say that they are without their drawbacks!.
Just my own opinion

[Don Plumley]

Thanks to all for for sharing your thoughts and opinions. Next time I'll try asking a controversial question :-)!

Thanks again,

Don

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don@plumley.org
Das Zoom - '87 Carrera

[movin]

Just one more,
Ford equips the Cobra R Mustang with a K&N air filter and K&N airfilters were used in Desert Storm on the Apache Helicopters.

[TC_SJ]

my 87 has K & N, no problem ever since. May be just opinion like some one does not like performance chip as well

[Craig 930 RS]

K&N on non Mass Air Flow cars before (1994 & before) = ok but hyped product
K&N on MAF cars (1995 and on 911) = oil crap on hot wire sensor

Craig
@RS