Debate continues: K&N filter vs. MPG

[dremd]

I know I posted this in another thread, but I'll do it again.

Air Filtration Test

My theories on increased mpg with K&N filters are as follows
1) some EFI systems are in someway fooled by the minor change in airflow.
2) the AFM / MAF is slightly damaged (well documented that the oil on them does harm sensors) and causes a lean condition.
3) (My personal favorite!) most people install them as Cold Air intakes, under the warm hood, typically factory intakes draw from a much colder area (fender/ headlight), therefore what they are installing is a Warm Air Intake.
4) Aliens from Mars
5) (second most probable in my book) It's just a placebo effect. And may be furthered by people maintaining their vehicle when they do the install.

[nascarnation]

It's been well documented that the filter is a very small part of the overall inlet restriction. It's also well documented that if you're driving for fuel efficiency, you will not be needing anywhere near the max airflow.
So to me it seems that any K&N benefit (much like "synthetic" oils) is from a placebo effect.


I would like someone with a scangauge to run tests with the most clogged filter they can find, a clean K&N, and no filter at all. (and don't worry about that last one, I know a guy who ran a 283 Chevy for 100,000 miles with no filter at all)

Any takers?

[Unforgiven]

Hmm, sorry, dont like the idea of absolutely no filter to prevent stuff from being sucked into the intake. As far as a placebo effect goes, and other doubts, there can well be times when a filter upgrade does not work as intended. For my results, I have the improvements based on numbers so I am content with what I see as a positive result.

[mavinwy]

On the wife's intrepid, we put in a "drop in" k&n and removed the sound reduction box, replacing it with a smooth tube. No other chages were made. 2mpg around town and 3 on the highway additional has been observed for better than 60k miles. I still clean and re-oil the thing every 10K miles and I have a standard paper filter that I put in while it dries overnight. It is consistant that we lose that 2-3mpg whenever the paper filter is in.

Now, this is how it reacts to one car. I have also seen cars where acetone worked, and others where it did not. Some where a certain brand or weight of oil made a difference. I think it may, in part, have to do with the design of the intake and engine of the car.

The neon has one, but that was to get rid of the "habitrail" intake that dodge put on the first generation neons. And yes, I am running it as a warm intake, so I would not just say that the k&n made a difference....but certainly the whole system did (about 3 mpg).

As long as there are different cars and motors out there, and people wanting to achieve different goals with them (speed, power, FE, reliability, whatever)....I think the great K&N debate will continue.

Jim

[Clev]

When I bought my Ranger, it has a K&N in it. It was running rough, and I realized that the MAF sensor was gummed up. I suspect it's the gunk that you use to "oil" the K&N, and after the first time I had to clean it, I realized that it's a messy job, and the old oil and dirt ends up in the storm drains, so I just tossed it and went back to the OEM. Absolutely no difference in mileage or power (though it runs better now that I cleaned the MAF.)

[dremd]

Originally Posted by nascarnation

. . . .. any K&N benefit (much like "synthetic" oils) is from a placebo effect.

Not to go off subject; but synthetic oil does allow you to increase FE; not because of magic; because you can run a lower viscosity oil, which flows better; saving energy.

Originally Posted by nascarnation

I would like someone with a scangauge to run tests with the most clogged filter they can find, a clean K&N, and no filter at all.

I think we can all agree that the SGII will not be capable measuring for this test. THE SGII works off of reported Engine Load which is based on airflow; if the K&N flow was the benefit then the throttle plate would close more, ending up with the same airflow and same reading.

[QUOTE=nascarnation;64856]
(and don't worry about that last one, I know a guy who ran a 283 Chevy for 100,000 miles with no filter at all)
I know 2 people who routinely run without airfilters.

1) Honda civic with Prelude engine swap; picked up a rod knock on second oil change, sand could be seen in the oil and the filter was entirely plugged (bypass stuck, low oil pressure actually caused the rod knock)

2) 2003 Trans Am Full exhaust, cam, tune, built auto, 3500 stall, no air filter. ~40,000 miles to date with no issues; however he does have a fine "pre filter" on the car. . . . ..

[aerohead]

I recall a very long and heated debate with respect to the K&N over a year ago at maxmpg.One member posted a laboratory investigation of air filters.As an air filter,K&N lost on all counts,least effective in removing particulates from the passing air stream,and fouling sooner than any other filter tested.------------------------ K&N is a holdover from the day of the oiled horsehair filter,long since abandoned by the auto industry and even lawnmower manufacturers.---------------------------- The solvents and oil required for maintaining the filter over it's service life,help perpetuate N.America's reliance on foreign oil,add to airborne VOCs,and help destroy the US balance of trade.--------------------------- It's my opinion that K&N should be limited to racing applications,where the engine operates in a controlled environment,and has no place in ecomodding.Premature engine failure do to accelerated piston ring wear runs counter to efficiency.

[tasdrouille]

Measure the pressure drop of the whole intake, and measure just the pressure drop of the filter. What you'll find is that your filter is very likely the smallest restriction in your intake. Do it at various rpm and you'll probably find the filter accounts for less than 2 inch of water below 4000 rpm.

The eleminating negative boost articles at autospeed are a good read.

[Formula413]

Originally Posted by dremd

2003 Trans Am

Production of the F-Body cars (Camaros and Firebird/Trans Ams) ended after model year 2002.

[dremd]

Originally Posted by Formula413

Production of the F-Body cars (Camaros and Firebird/Trans Ams) ended after model year 2002.

poop you are absolutley correct; I'll call him in the morning and see what year his car is. Ls1 car. . .