is a K&N air filter worth the money

[troy.70R/T]

I was just wondering if any of you are running a K&N air filter and wether or not you think they are worth the money. A couple other questions that I have are.
      1. What about the ones where the top cover is a filter? I know it increases air flow but is it a smooth air flow or choppy air flow?
      2. Is there enough filter area on the top filter to sufficiently stop dirt???
     

[femtnmax]

From what I have read in both mag articles and from forum moderators, the K&N air filters really perform.  Th top filter is supposed to really help increase air to the carb, but the biggest issue I have heard of with the "top" filter is if you have an engine backfire, it can burn the paint on the underside of the hood.
I will be running K&N air filter on my mopar v8 when I get it running hopefully this summer, but I won't be using the "top" filter just to protect the new paint job.

[68X426]

I use a top filter and bottom filter. The air flow is practically infinite. Is the air choppy? Don't know, can't know, but the real world performance difference over a closed filter is stupendous, so choppy or not, it works for me (normal driving as well as racing).

The engineers can measure it, but if choppy is 95 percent efficient and the cfm is 99 percent, I will accept that over 100 percent efficient and cfm at 30 percent.

The filter is at it's best at stopping dirt, unless you are off-road racing, then you would want an upgrade for dirt(y) conditions (foam or special technology).

Yes, it's worth it.

[BB1]

 

[troy.70R/T]

can you give me some idea on what you guys have. I will have a 383 or 400 in my 68 charger untill I get a 440 built. I will be running a dual plane intake. (not sure what kind yet) and a holly or demon 750 carb. I just don't want any clearance issues but would like to get the biggest filter that will fit.

[68X426]

In order to manage clearance, you have to account for at least major 3 factors: the base, the bottom filter, and the top (solid or breathable) and how all three interact with each other, as well as a dozen or so unique "little" factors, each with its own interaction.

The greatest factor for clearance is the drop that is built into the base. I've seen drops of 1/2 inch all the way to 2 and 1/2 inches. The more the drop, the more height in the bottom filter you can run. If using the breathable top filter then the drop isn't as critical to the total cfm, because you gain so much cfm capacity and can still use the shortest 2 inch bottom filter.

My experience is to find the most drop available, the most height in the filter, and top off with the breathable filter, and see to it that no part of your unique assembly rubs on linkage, brackets, or hood.

Some bases have rises built in, sometimes an inch or more. You may find a base with zero rise/drop works for you. Perhaps you have a rise base, don't even know it, and that is the cause of a clearance issue. Bottom filters run from 2 inches to 6 or more in height. Perhaps just a shorter filter can solve a problem.

Note: a drop of 2 inches can't use a 2 inch filter. I've read that an effective bottom area of at least 1/2 inch has to be maintained even with a breathable top. So if you can run a radical 2 and 1/2 drop you will still need a 3 inch bottom filter. Add another 1 inch for the top's overall height (thickness of steel and filter), and you still have a total measurement of 1 and 1/2 inches over the top of the carb flange.

If that isn't enough clearance (because of the heights of your particular intake, carb, k-member and/or mounts) then you are looking at a hood scoop, or a plenum and cold air intake (which can get extreme as well as pricey).

You have to determine the clearance you can't see, just feel, under the base. And then account for linkage and brackets around the outside of the base. Summit, Jegs, and lots of internet retailers sell a wide range of drop sizes (assuming you are using a 14 inch diameter).

On my Hemi Road Runner I have a 14 inch base, with a 1 inch drop, 2 inch high filter, and a 14 inch diameter breathable top. The top edge rubs the hood in one small spot and I'll get a 1 and 1/2 inch drop base soon in order to end that rub. That is the most drop that I can run and the most bottom filter.

Good luck, 

[Cooter]

As long as when they are run in a F.I. vehicle, you clean the mass air flow sensor at least twice a week depending on mileage driven..



The K&N oil gets all over the MAFS and screws with it bad..Seen it too many times with the newer cars...Older cars, I guess every little bit helps..

[troy.70R/T]

thanks for the tips 68x426. I kind of figured I would have to do some trial and error untill I found the right base. I will just have to pay more attention to cars at car shows this year and ask some questions.

[alcusswhen]

Hot Rod Magazine did a dyno test a couple of years ago. And K&N did no better than the other top of the line filters.

[62 Max]

And I don't buy "the dirtier it get's the better it works"

[Back N Black]

I picked up 8hp on the Dyno using a K&N filter. 

[gtx6970]

I put one in my Ram 2500 , picked up 1+1/5 MPG driving the same route and same way as before

[resq302]

I have a stock replacement K&N filter in my 383 4 bbl unsilenced air cleaner housing.  Works fantastic.  Plus I get to clean it whenever I want, its totally hidden so still looks stock and gives me better throttle response it seems.  I run them in my daily drivers too.... my truck is a 2005 Ford F150 with the FX4 package, 5.4l V-8 and my wife has an 2005 Ford Explorer Limited with the 4.6l V-8.  Both vehicles have the stock K&N air filter replacement and picked up mileage on them.  Again, for the price of what a new filter would be, you actually save money by being able to clean the reusabale filter I think.