K and N questions

MAS · MAS's Garage

My mechanic just gave me a K and N filter for my 77 911S 2.7 to test out for a few days (nice guy!). Anyway, it's the standard size air filter that fits into the stock air box.

I haven't really had a chance to test it out yet in the city today, but I did notice a slight change in the engine "intake" sound at around 3,500 RPM... a very faint whistling sound. As for any performance increase, as I said, I've got no idea yet.

Anyone else:

1) Think K and Ns are worth it,

2) change the engine sound slightly at upper rpms, and...

3) provide a noticeable, if small, power increase.

[and yes, before anyone jumps on me, I did attempt several times to do a topic search. Unsuccessfully, because the letter elements in the search were flagged as "too small" for the search engine]

-MAS

Rot 911 · 06-01-2004, 01:03 PM

Yeah those searches are hard.

K & N Air Filter

JMar · 06-01-2004, 01:05 PM

Quote:

Originally posted by MAS
My mechanic just gave me a K and N filter for my 77 911S 2.7 to test out for a few days (nice guy!). Anyway, it's the standard size air filter that fits into the stock air box.

I haven't really had a chance to test it out yet in the city today, but I did notice a slight change in the engine "intake" sound at around 3,500 RPM... a very faint whistling sound. As for any performance increase, as I said, I've got no idea yet.

Anyone else:

1) Think K and Ns are worth it,

2) change the engine sound slightly at upper rpms, and...

3) provide a noticeable, if small, power increase.

[and yes, before anyone jumps on me, I did attempt several times to do a topic search. Unsuccessfully, because the letter elements in the search were flagged as "too small" for the search engine]

-MAS

Here's my take:

1) Think K and Ns are worth it, NO

2) change the engine sound slightly at upper rpms, and. Maybe but not as much as drilling the cover does.

3) provide a noticeable, if small, power increase. NO, the stock filter (so long as it is not overly dirty) can flow as much air as the engine can take.

BTW, If anyone want's a K&N for a 84-89 carrera I have one you can have for $10+shipping

eurocarrera · 06-01-2004, 01:05 PM

You will hear hundreds of opinions on this subject - do a search the debate is heated.

Someone made a good point, the amount of dirt that gets into the engine over stock is minimal, and the fact of the matter is user X will have spent $$$ on replacement filters annually (or sooner) whereas, user Y (with the K&N filter) will just re-oil his/hers, and thus have an eventual gain in $$ from not having to purchase paper filters.

I have never heard anyone blame a K&N filter as to why their engine blew up, so I use mine now instead of letting it sit up on a shelf.

Good luck!

KobaltBlau · 06-01-2004, 01:07 PM

another thread found by searching for:

"filter k&n"

more info on K&N FILTERS (bad news)

eurocarrera · 06-01-2004, 01:07 PM

BTW, I have also drilled the cover of my airbox like it shows in the Bently manual, and I LOVE the sound!

MAS · MAS's Garage

OK, I enter K and N into the search engine and get nothing, What do you do so the search engine reads the phrase rather than the letters. For example, with Alta Vista you place quotation marks around the phrase/letters.

(note my lack of sarcasm in my reply)

-MAS

beepbeep · 06-01-2004, 01:10 PM

1. no
2. yes
3. no

KobaltBlau · 06-01-2004, 01:52 PM

Quote:

Originally posted by MAS
OK, I enter K and N into the search engine and get nothing, What do you do so the search engine reads the phrase rather than the letters. For example, with Alta Vista you place quotation marks around the phrase/letters.

(note my lack of sarcasm in my reply)

-MAS

this search engine doesn't seem to do the phrase thing, or at least I haven't figured it out. The "too short" thing sucks too, for instance SC or RS are under 3 characters but you really do want to search for them.

I just cheated by searching for filter and k&n so the search engine treated k&n as one term, and it was long enough.

MAS · MAS's Garage

Quote:

Originally posted by KobaltBlau
this search engine doesn't seem to do the phrase thing, or at least I haven't figured it out. The "too short" thing sucks too, for instance SC or RS are under 3 characters but you really do want to search for them.

I just cheated by searching for filter and k&n so the search engine treated k&n as one term, and it was long enough.

Yeah... I went "K and N" then "KandN". The first yeilded no results and the second, two results.

-MAS

MAS · MAS's Garage

Quote:

Originally posted by MAS
Yeah... I went "K and N" then "KandN". The first yeilded no results and the second, two results.

-MAS

[... still no sarcasm in my reply]

fireant911 · 06-01-2004, 02:06 PM

I would thank the mechanic (simply as a courtesy) and promptly return the filter. Engine longevity is very important to me and I saw that the filtering capabilities of the K&N were not up to par.
Please see the link below especially noting what Doug Zielke said about the 'dirt road test'. I was flabbergasted but the about of trash that passed through the filter K&N filter (which was properly maintained) fitted to my car without ever getting off the pavement. My K&N is occupying some space in a land fill.

K&N Filter - Opinions?

RoninLB · 06-01-2004, 02:59 PM

someone posted that consistant reoiling is necessary.. maybe every 5-10k miles.

raceman · 06-01-2004, 03:53 PM

don`t buy an air filter expecting a performance gain because you won`t get one unless the filter you replace flows a measurable amount less then the replacement. K&N makes a good product for a huge variety of applications,and they`re a lifetime purchase if maintained, unlike a filter made from a tree.With my induction system l can`t use a wood filter so l`ve got the wretched K&N. l watch it closely for signs of revolt and dryness.lt`s pretty clear though that the cotton used in the filter would be much more at home in a pair of jeans but until l upgrade to the oil bath l`m sticking with it,despite the bad press. l have a friend who swears buy the Amsoil foam filters and says they beat all comers hands down for flow and filtration.l may look into that,apparently the foam used is specific for mega filtration

eurocarrera · 06-01-2004, 09:42 PM

Since everyone tends to rag on K&N filters can someone tell me exactly how efficient are the filtration systems on some of the older cars which look like they just use velocity stacks? I have just seen some with screens - what is that like .5 millimeter paticles that are being let in?

sushinav · sushinav's Garage

I'm with Bill on this one. I've even seen pics of those cool velocity stack cars with tennis balls sitting in the tops. What the heck kinda filtration do you get through a tennis ball?!?

Ray B · 06-02-2004, 04:05 AM

Probably not much filtration on those old stacks. Then again, how long did those engines last?? I might run stacks too if I had a team of mechs to rebuild my engine after each race. K&N seems like a decent type of filter but not worth it IMHO. Power increase is akin to how your car drives better after you've washed it.

Rick Lee · Rick Lee's Garage

Quote:

Originally posted by Ray B
Power increase is akin to how your car drives better after you've washed it.

Are you kidding me? Where do get your car washed? My car drives MUCH better after I've washed it. I'd say a Zymol wax is worth another 10HP too. Cars have personalities and do reward meticulous owners.

RoninLB · 06-02-2004, 05:19 AM

if you buy into dirt and reoiling K&Ns on my last reply.. and because I think I'm stuck w/them because of the watershields.. then I'll wipe a clean finger inside the can.. if clean finger then no problem imo.

eurocarrera · 06-02-2004, 06:51 AM

hmmm.....isn't gas actually a petroleum product, and doesn't it leave a bit of a residue, or do you use synthetic gas?

The argument was that the cost over the long run is less with the K&N than paper filters. In regards to particles going by the filter, I also stated that no one has ever mentioned a failed engine due to a K&N filter. Getting down in the microparticles I think is just silly. Most of us experience somewhat normal climates, and don't drive through sand storms daily.

In regards to horsepower, I don't notice a plus or a minus, BUT my car certainly revs faster to redline with the airbox cover drilled, and the K&N filter in the box.

I had someone drive my car without telling them about the airbox changes, and they right away noticed how fast it was to redline, and how peppy the car was. That is testimonial enough for me.

BTW, is anyone filing suit against K&N for failed engines or excessive wear?? We have enough lawyers represented on this board, and I am sure that they would offer assitance.