I was going to stay out of this thread but... Well, I can't help myself so here goes.
Based on info and belief,Throughout the years k$n has had to reduce their HP claims a few times. One has to wonder why. Well, claiming at one time in a ad that their filter would increase rear wheel 25 HP is false advertisement imo.
Also Cummins iIrc in about 2004 would disallow warranty claims on intake related damage if equipped with a k$n. Gotta wonder why.
Here's one that really makes me wonder. If with all the money the big three spends on engineering for more performance why don't they use them?
But you spend your money and the SOTP dyno tells ya it's the balls soooo..................
Without discussing the merits of one filter media over another, we can look at restriction.
Your paper filter is probably not restricting air flow. There are lots of tests that show a clean air filter is not restrictive.
The only way a filter can improve power is by having less restriction at wide-open throttle. At anything but WOT, the carb or FI butterflies are the only restriction. The air filter makes no difference unless it is REALLY clogged, so, I doubt claims of any filter increasing performance or mileage except at full throttle unless the previous filter was REALLY clogged.
If you think a filter with less restriction can give you more power, remove your (clean) element and do a stopwatch or hill climb test. Do not be seduced into thinking more intake noise is more power.
Mileage? Well, maybe a lower-restriction filter might possibly improve full-throttle mileage, but who measures that?
Maximum flow is overrated, anyway. Some expensive dyno time has told me that power drops off at somewhere around 20 inches WC. The more stock the engine, the more restriction it will tolerate. You can measure restriction yourself with a clear vinyl tubing manometer.
Do yourself, your engine and your pocketbook a favor. Buy a filter minder and change the filter only when it shows 20 inches H20 of restriction. A Filter Minder will pay for itself in avoiding premature filter element replacements, too.
http://www.bobistheoilguy.com/airfilter/airtest1.htm is an interesting test of air filter elements.
http://www.duramax-diesel.com/spicer/index.htm is another test,
Hot Rod Magazine did an air filter element test using both a dyno and a flow bench in their June 2002 issue. They found no advantage to using a K&N or similar.
From the article:
"As you can see, there was very little difference between the filters tested, though the paper element did lose a few ticks as compared to the performance units. In fact, the power numbers are so close as to be identical compared to testing repeatability. However, the one thing we were not able to fairly quantify is airflow performance after a given amount of contamination, and we suspect that’s where a slight difference might show. You’ll have to sort through the advertising claims and make your own call based on price, warranty, and—sad but true—appearance. Also keep in mind that while the paper element is the cheapest, it also gets dirty faster (as evidenced by the seat-of-the pants power you can feel when swapping a used paper filter for an aftermarket one), is not reusable, and probably does not filter contaminants as well."
Several years ago, Sport Compact Car magazine tested ~12 air induction kits, including the K&N FIPK, and a K&N drop-in filter on a new Honda Civic. All the complete kits increased hp/torque a little, but the drop-in replacement element's affect was "transparent" . . . i.e., no increase/decrease in hp/torque.
There have been many other tests, but most of the links I have collected no longer work. Similar results, though.
The ideal situation for filter monitoring would be a permanent gauge on the dash with a tell-tale max needle. I have not seen one with the needle. SW makes a basic one. There are dash-mounted indicators that tell the max vacuum, just like the ones on the air cleaner. I use a Filter Minder remote mounted indicator connected to my air cleaner housing, and check it before every trip. I made a remote installation to avoid the high temps in the engine compartment. Air cleaners last a long time on hard road vehicles.
As to the temporary manometer, a length of clear vinyl tubing connected to the air cleaner housing and run to the cockpit is all you need. Any size is OK. Tape it going straight upward on the sidewall, then going down, then going up again, with the open top end two feet above the lower curve. Fill the tube from the top end with colored water until the level is one foot above the bottom of the loop. When the levels are equal, there is no intake restriction. When the levels are unequal, the number of inches they are apart is the amount of restriction you have, measured in inches of water. I have never seen a reasonably clean paper filter with much restriction.
Disclaimer: I am not a Diesel guy, so some of the stuff about throttle position probably does not apply to diesels.
NOTE: Any incorrect spelling is intentional to prevent those annoying popups.
84 Barth 30Tag powered by HT502/Thorley/Weiand etc, Gear Vendors OD.
Siamese Calvin and Airedale Hobbes, 4WD Toyota toad
Three people so far. I have to admit I only kept two of my vehicles with K&N filters long enough to accumulate over 300 000 km on each; 1984 Jeep Cherokee and 1991 Nissan Sentra.
Add me to the list. I went down to Northern Mexico in my coach. Came back and decided to check the filter. Took it off and held it up to the sun and looked inside. I looked at a number pin holes with light shining through.
That was when it was taken off and replaced with a proper filter. In my case, I replaced it with an OEM H2 Hummer canister and filter which is made by Donaldson.
I have personally met a bus owner who had to spend about $10,000 to have his Detroit 8V92 overhauled because of fine dirt that got by his K&N filter. I believe this was an older style K&N heavy duty filter and not the current designs. I recall that his issue was the filter didn't fit the housing properly and dirt got around the filter altogether.