Written by Mustangworld.

Lots of pics, I hope your on the net at 28.8 or faster.

Pic of K & N Boxes

This is what's in the box.
K & N Air filter and cleaning kit . Filter $45,
Cleaning Kit $10. This is what comes in the box.

 Ok, so you want a little extra HP for under $60 ? Purchase a K & N Air Filter ! There are other performance filter manufacturers out there all using the same basic principle to improve air flow...using cotton instead of paper for air filtration. But remember, cotton alone will not work, you also need a slight "film" of oil on the cotton to ensure the cotton grabs all the dirt and grime. This oil gives the cotton a reddish / orange look. Don't expect to "feel" a great increase in HP. Expect a stang that sounds a bit louder at high rpms, revs up and down a little faster, has a little more pickup coming out of turns and breathes easier. The HP gain depends on your mods, but on a stock stang, I'd say from 2 - 4 HP.

 Another reason to buy a cotton filter is the ability to wash them and re-use them. Some of us here live on dirt roads and we have to drive several miles on dirt to get to our houses in the hills (this is where we also "rally race" our stangs, like a bunch of Pikes Peak racers) the air filters get real dirty, real quick. Without a K & N Air filter, we'd have to buy 2 filters a year just to maintain a clean intake. A cotton filter can be washed and re-washed to work like new, for the life of your stang.

 You can also purchase the K & N "Filter Charger" system for $89. This is a system (includes a metal bracket and air filter) that completely replaces your air box and runs the filter element completely exposed to maximize air intake. Some may say: "hey, that means that you are sucking in hot air from under your hood!" True, but a completely open element means better flow, cooler air means slightly better combustion because the air is more dense, but hot air burns efficiently in a normally aspirated 4.6L as well. A sensor reads the air temperature for best combustion. Cooler air still enters through the hole the air silencer took up and from the entire bottom of the engine. The only time the cool air factor comes into play (in this case) is on cold winter days anyway, if it's hot outside, it will be hot under the hood, you'll need an intercooler (aftercooler or air to water cooler) to really make any difference in performance if air intake temperature is of any concern to you. Keep in mind that in some situations, an open air element may get dirty faster than one that is inside a filter box. We just went with the regular $45 air filter element alone, a stock air filter replacement, because this project stang will see dirt road action almost every day. We left our stock air box in place, but still removed the air silencer.

Get the right part no. for your Stang. This particular application was: 1996 Mustang 4.6L V8 K & N Filter Part E-0945. Cleaning kit 99-5000.


1. Here's the 4.6L Air filter box. We've already removed the air silencer, so replacing the air filter is a piece of cake. With the air silencer in place, it's more difficult because the air silencer goes into the fender well about 10" or so. We only have to remove one bolt and a latch, I'm touching both with my hand. 4.6L Air filter Box
2. What we'll do is undo the bolt that is holding the top of the box in place. The bolt comes completely out. When you put this bolt back, careful not to over tighten it. Un bolt using a wrench.
3. Next we'll undo the big latch that holds the filter box onto the MAS assembly. This latch is attached to (and comes out with) the air filter box. Un-Latch Top Latch.
4. Now, we just lift up on the whole thing and pop the whole box (with latch) out forward. You can see the stock paper element inside. Looks like a 747 Jet engine intake ! Notice one of the rubber grommet holes at the bottom of the fender well. Their are two. You'll need to lay the box down back into these two holes when you put it back. 747 Jet Intake Look alike.
5. Now just pop off the air box. Your filter may stick to the MAS assembly like ours did. As you can see, the big metal latch came off with the air box. Notice the two rubber grommets on the air filter box. Now is a good time to clean out the air box with a damp rag. Air filter..Exposed.
6. Clean off the air filter box with a damp rag. You can also hose it down if it's real dirty. Dry it off before re-installing, you don't want the latch to rust. The new K & N comes pre-oiled from the factory so all we have to do is pop it in! Air filter box w/K & N.
7. Now, lift the MAS assembly and fit the new filter over the extruded center tube. It won't be a perfect fit. The K & N element's hole is slightly larger than the tube, so you will have to hold the filter in place while you put the air box back on. You can see how dirty the stock element was with only 2 months of "off road" dirt road driving. MAS air, K & N, and Stock Filter
8. While holding the air filter in place, put the air box back on. Check for a perfect fit and rotate the box into it's final position, then clamp the latch down. Now put the whole air box back down into place, securing the two rubber grommets at the bottom. Last, bolt the box into place with the one bolt we removed earlier. Everything's in place !
9. The kit comes with a sticker that says "STOP YOU FOOL ! Don't throw away my air filter, I can re-use it !" It's wise to stick it some place visible. We put ours on the metal space to the left of the radiator, just next to the hood support on the passenger side. Stickers don't stick to well to the air box itself. This is in case you take your Stang in for service, you don't want the dudes to trash your filter. STOP! Don't Throw away my K & N!
10. This is the $10 Cleaning kit that you use to clean out your filter. When it gets dirty, you spray it down with this cleaner, soak it for 15 minutes, hose it down, dry it, then re-oil it with this oil. Your back in business. Every K & N filter comes with a million mile warranty. You can wash your filter like 10 times with this kit. Cleaning Kit.

Hey....yer totally done dede!....til next time.... see ya on the street !

Back to

Mustangworld Shop

MUSTANGWORLD.COM, the Mustangworld crest logo above and MOLLERNET are registered trademarks of MoLLER DIGITAL / DiscMEDIA INC. Copyright © 1986 - 1998 MoLLER DIGITAL. Some web elements on this site are copyrighted and are being used with permission from their respective owners. MUSTANGWORLD web elements may not be "re-posted" on any website anywhere in the free world without permission from MoLLER DIGITAL INC. All original graphics are digitally watermarked to aid us in copyright enforcement.