In an effort to find performance enhancements on my 1997 Chrysler Sebring JXi, I went back to the old days when (I was a teenager) you could flip the breather lid over and get another 2-4 mpg, a little better performance and a whale of a good sound. Taking a look at the Mitsubishi built V6, there’s not a lot of room around it for modifications of great magnitude. A very popular mod nowadays is cool air ducting and K&N air filters. I wanted a conical replacement filter and since it would be a while before I could get to a stocking dealer for some test fit-and-try, I focused on getting the maximum out of what I had and examined the airbox for possible enhancements or modifications. What a restrictive little device this is. There are two stages to my modification for a better breathing JXi. You may do one or the other, or a combination of them. Here’s how I went about making my JXi run better, sound better and get better gas mileage.  This is a pic of the stock air box as it appeared from the factory.  If the air box appears to be disconnected from the snorkel, it is.  Note the K&N sticker on the inner fender.  This is a post-installation recreation. These pictures were made on the date of my first cleaning of the air filter, at approximately 53,000 miles. 

 The stock air box on the 2.5 liter V6 forces the multivalve engine to breath through the tiny baffle you see at the left of the opening.  See below for a more dramatic shot.  This opening is approximately the size of a business card.....not much air for such a healthy engine hauling around a 3200+ lbs. car!  Something must be done!  The first stage of my modification was to get more air to the air filter. You can do this and nothing else and feel better about the performance of the car. I’m not sure this modification changes the performance of the car all that much, but it sounds faster! If you used this in conjunction with a replacement hi-performance air filter, it might lend itself to ducting cool air to the engine which would be even a greater benefit.

Regarding hi-performance filters, take a look at the paragraphs below, but keep in mind that this car does not lend itself to ducting very well. Also keep in mind that the filter described below can be bought for less than $30 (well, not much less) while the replacement filter is generally in the $40 to $45 range. I wish I had taken the time and effort to duct air into the stock box from outside the engine compartment. There just seems to be very little space to do so. I would like to have seen the difference in performance with a cool air intake vs. the K&N and no duct. Anybody want to try it and report their results?

STAGE 1-AIR BOX MODS

With the help of my good friend, Dremel, I enlarged the opening from 1 business card size to approximately 2.5 business card size.  This plastic material is very easy to cut with the Dremel tool.  I was able to slice and dice pretty much as I wanted.  This Stage 1 modification increased the noise level to a low whining moan.   Performance was not effected radically.  When the air box was re-installed, you could not see the increased opening size at all.  The shot below is another of my Dremel handiwork.

After you pop the lid off the airbox, remove the filter and pull the airbox free of the plastic press-nuts that hold it onto the inner fender. Take out the little baffle in the bottom of the airbox. Then, take your dremel tool or a small hack saw and open the bottom of that box up.

STAGE 2-MAKING THE CUT

Finally, I made it down to Hunter's Automotive in Nashville, TN (toll free at 888-674-9558) for some trial and error filter selection. With their help I selected and bought K&N filter # RU 3130 for $29.99. It is a conical filter with a much more free flow design than the airbox replacement filter.

Below  is a shot of my favorite tool (Dremel) and the air box lid.  I removed the entire airbox, separated the top from the bottom (as you would to replace factory filter). Then I cut off the nipple that the rubber air intake hose attaches to, leaving the big flange which the hose to butts up against, intact.  This nipple is long enough and contoured such that the K&N can be easily and permanently attached. 

This is how the lid interfaced with the snorkel.  You can see some of my silicone resudue along the bottom edge of the snorkle.   

STAGE 3-INSTALLING THE K&N FILTER

I forced the nipple into the K&N, forming the neck of it into an oval shape. The neck of the filter is very pliable and the flange takes up some of the open space.    A good bead of RTV silicone sealed the K&N to the nipple, and then I tightened the K&N clamp on it, making sure I centered it over the flange. Otherwise it will slip to one side and force the nipple out of the filter, leaving a gap for unfiltered air to get in. 

When it was all over, I took a hammer and tapped the plastic fasteners out of the bottom of the airbox to put back over the studs that held it in place. That'll keep them from rubbing a hole in your new K&N filter. The screwdriver below points to an airbox mounting stud  you will want to cut off before completing the K&N installation.  I cut this stud off flush with the reinforcing nut, with my trusty Dremel, so that it wouldn't poke a hole in my new K&N.  

Below, left, is another shot of the snorkel, factory clamp still attached.  On the right is a freshly cleaned and oiled K&N filter # RU 3130.   Note the gray plastic nipple of the air box (see above) is already inserted.   I used ample amounts of clear silicone to both seal and cement the soft rubber neck of the K&N to the former air box nipple.   

Finally, I slid the nipple back into the factory air hose, where it had been before and tightened the factory clamp on it.  Attaching the hose clamp to the K&N works best if you can locate and clamp it right on top of one of those "humps" in the nipple to keep from squeezing it out--again, silicone really helps here to both seal and cement the filter into place.  Done!

So, there you have it, a nice, clean, relatively simple installation of the worlds best air filters into the world's most beautiful 4-passenger convertible!

The Dremel is not necessary, you could use a hack saw or coping saw, if you prefer.  The Dremel has been one of my favorite tools since my son's did Cub Scouts Pinewood Derby (that's a whole 'nother story!)!

Regarding cleaning the K&N:  When I made this pics, I took the filter, plastic nipple and all in the house, shot it down with K&N cleaning solution (while it was sitting on a stack of old newspapers) and let it soak.   After about 10 or 15 minutes.  Then I flushed it from the inside out with the kitchen sprayer .  I repeated the process twice, until the water I was rinsing out was pretty clear.  Then, while I made pictures and did other chores, it dried--first in the sun on the patio and then over the furnace vent.  By the time I had finished "tinkering" with my car, the filter was dry.  I sprayed it with K&N red oil and let it soak, according to the directions and looked for any gaps.  There were none, so I replaced it as you see it above!