Ive had a K&N air filter for about 40K now. the other day i noticed that the "%used guage" was at 100 %. i am tryin to detirmine the problem here, i clean the filter regularly and i reset the guage but it seems to go right back down after 20-30 miles.
could my k&n possibly be goin bad, or has anyone ever heard of a faulty guage on these things? as soon as i get a chance i will steal my dads clean stock air filter and compare the egts and the %used guage. but until then, does anyone have any suggestions?

thanks a lot for any feedback.
peanut

 

What was the filter minder like with the stock filter? I read in another thread that some trucks were equiped with an incorrect model, but I thought they were 3rd gens.

I have heard that the oiled guaze filters can actually be a restriction instead of an improvement. I lost 3 mpg's on my gasser V-10 with the K&N, so I pulled it out and went back to stock paper. My mileage went right back up. Ticked me off, since the K&N was a special order I couldn't return! I noticed zero performance gains with the K&N over stock, too.

One of my next mods will probably be a BHAF and heat shield, if I ever get around to it.

 

have you noticed a difference in performance?? black smoke, low boost or higher EGT's(that you said you were gonna look for)?

A lot of folks on this board, myself included, would try to steer you clear of K&N....

 

K&N isnt the best choice for a Cummins, imo. Lets through too much crap.

 

Found this on the web its a good read... In in regards to K&N filters and some testing of the element.

Jim Conforti (AKA the Land Shark) did some testing:
This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark").

A scientific test was done on TEST filters where air was loaded with ACCTD (some standardized "test dust" called AC Coarse Test Dust) and sucked through the TEST filter then through an analysis membrane. From the Quantity of dust injected and the amount that gets through the TEST filter and is then captured on the analysis membrane we can calculate the efficiency of the TEST filter in Question.

BMW Stock Filter, Eff. Area of Media: 8.4 sq ft.
K&N Replacement, Eff. Area of Media: 1.6 sq ft.

The filters are the SAME size. They both fit in the STOCK BMW M3 airbox. The difference is that the STOCK filter has 65 pleats 1.5" deep and the K&N only 29 pleats each 0.75" deep.
Now, remember this ratio: " 5.25:1". It's the ratio of the AREA of STOCK to K&N. It's very important and will come into play later.

The STOCK filter efficiency started at 93.4% at 0 loading and increased to 99.2% efficiency as the loading increased to a max tested of 38.8 gm/sq ft of dust.


The K&N filter efficiency started at 85.2% at 0 loading and increased to 98.1% at the max tested loading of 41.38 gm/sq ft.

Now, I hear you. "Jim, that's only a FEW PERCENT". But is it?

Let's look. If we had 100 grams of dust on a new BMW filter we would let through a total of 6.6 grams of dust in. If we used the new K&N filter we get 14.8 grams of dust. That's 224% (TWO HUNDRED TWENTY FOUR PERCENT!!) more dust ingested initially, stock vs. "free flow" and this ratio is pretty much held. Somewhere between 200-300% more dirt gets "ingested" anywhere across loading equivalence. The more INTERESTING thing is when you look at what happens to the DP or Differential Pressure at a constant airflow as you dirty both filters equally with time.

The test used a rate of 75gr of dust per 20 min. Here's where the AREA difference comes MAJORLY into play. See, even though the BMW filter flows a bit less at the SAME loading, it also LOADS UP 5.25 times SLOWER due to it's LARGER effective area. So what happens is that the K&N initially flows better, but as the dirt continues coming in, the K&N eventually flows WORSE while still letting MORE dirt in.

Now, does any of this additional dirt cause problems? I dunno. I suppose we could have a few people do some independent oil analyses on different motors using both K&Ns and Stock filters. Get enough of them, and you'd have a good statistical basis. For me though, it's simple: More DIRT = BAD.

The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.

-- Jim Conforti

 

My truck had a K&N in the stock air box on it when I bought it, I would like to put something else on it, I would also like to do something to help lower the EGT's a little, will the BHAF help on EGT's? as compared to a Scotty with no hole? Also who makes a good kit with the filter and heat shield? Thanks

 

my truck also had a k&n in the stock box when i bought it. i have been wondering about this for a while now, as k&n doesn't seem to have many supporters on this site.
is there a better filter to put in the stock air box - go back to a "stock" filter. or go to a BHAF / scotty / ????

 

The Scotty Systems now use a dual stage Foam filter custom made for my products.
Folks in Baja will use this over the oiled gauze.

Our first order of Scotty Air II's with the UNI filters will be ready to ship this week.

 

Scotty, any pics of the new Uni filter? I am going to be ordering a Scotty II soon and I am very interested in seeing what it looks like compared to the AFE element.

 

I've used K&N for 150K miles. No problems here that I know of. I've never seen my minder move.

I've used K&N on all my airplanes also. Although I don't fly in much dust!

 

is there a web site for these scotty filters?

 

I see them for sale at Wildcat Diesel Performance. Try there, since I think Scotty works with Rod there. Not sure, of course, but they seem to be listed together a lot!