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K&N's YJ FIPK

FIPK (Filtercharger Injection Performance Kit) is a fancy way of describing a product that improves air flow to your engine, thereby increasing horsepower, throttle response and maybe even fuel effeciency. Of course, everyone has heard of K&N, a premium brand in the performance air filter business, so I was naturally excited to hear that K&N not only manufactures air filters but also exhaust systems and air management systems such as this FIPK kit. Their reputation for high quality products is excellent and I've used their filters for years so I had no trouble deciding to try their FIPK kit. K&N has a kit like this on the market for TJ's and now they've decided to release a YJ version. I should mention that when we started looking into the FIPK, we lived 5 miles from their plant in Riverside, California and I heard from a friend about the development of this new YJ kit. K&N kindly agreed to use Velociraptor as sort of a test vehicle for the new kit and we're heading in for dyno testing this week followed by the install later this month. Expectations are up to 10 extra HP and improved throttle response throughout much of the typical engine rpm band. Engine-wise, Raptor has a completely stock 4.0 I6 with less than 53,000 miles on it as of this writing. Overall, I can feel a difference in throttle response and acceleration in the low and mid range. I also like the slight whistle sound the filter makes as it suchs in more air than ever before. I used to own a twin turbo Nissan 300 ZX and it kind of sounds like a turbo. I like stuff like that :-). The instructions that came with the kit were complete, easy to follow and I love the fact that they include the steps in pictures as well as text. There were no problems installing this kit. One more thing - it looks neat. There is some value in having upgrades that perform and look well, don't you think?

Price: Around $240 retail

Where to buy: by the time you read this, most offroad product retailers, such as Quadratec.

Tools needed: standard screwdrivers and socket set.

Difficulty rating: easy

Time needed: allow an hour but you could finish in as little as 30 minutes.

I was excited about the kit showing up so I could have it installed before the 2003 Tierra del Sol Desert Safari, an long weekend trip we make each year to a desert 4x4 gathering near the Salton Sea in Southern California. With 31x10.50's (as of this writing) and stock 3.07 gears, we haven't been able to use 5th gear very much and I was curious to see if the K&N FIPK would make a difference.

To install just follow the excellent instructions provided. You basically remove the old filter box, attach a bracket to the same hole used for the power steering pump, attach the heat shield, attach the filter to the tube and secure the tube. The hardest part of the install was affixing the rubber gasket arround the heat shield. The fit is tight and it doesn't go on very easily. You'll probably curse and wonder if it really goes on that way (it does) but eventually you'll muscle it on. At least it's not likely to come of very easily.

Make sure you affix the DOT sticker or you might have trouble next time you have your Jeep emissions tested.

I recommend buying the K&N filter cleaning kit and cleaning the filter a couple times a year or more if you live in a dusty place like we do. Some accuse these high flow filters of allowing too many contaminants to reach the engine so it's probably best to keep the filtration part working as well as possible by keeping it clean.

Just for fun, here is how the timeline went for bringing the product to market. These things take time and I learned a lot about getting a product approved for street legal use:

TIMELINE:

8/3/01: First Dyno test results can be seen here. Remember, this measures horsepower to the rear wheels and is NOT the same thing as the stated HP of the stock engine (which happens to be appx 185 HP). K&N tested 3 prototypes and it looks like they should have no problem pulling 10 extra HP to the rear wheels!

9/8/01: K&N Engineering is still perfecting the mounting system expects to have it done shortly which means it should be installed shortly!

12/2/01: K&N Engineering put the FIPK on the back burner for a few months but Raptor is scheduled for a Dyno testing again tomorrow (12/3). In the preceding months they finally found a third YJ to test some ideas on and found a few ways to tweak the setup some more. K&N assures me they very much want to introduce this product and I expect we'll have it installed within the next month or so.

3/5/02: I just got done running what I believe to be the last beta test of the FIPK kit. I drove Raptor around for 100 miles so the engine computer could adapt to the increased air intake and then took it back to K&N for another dyno test. For the first 80 miles, I didn't notice much difference with the kit on but about 80 miles in, I could feel a positive difference in gas petal reaction. Also, I could hear the air rushing into the filter, which was kind of neat. If you've ever owned a turbocharged car, the sound is similar to the the turbo spooling up. K&N suggested they might have the finished product within the next month. Wohoo!

2/18/03: Product arrived! So it took about a year and a half to fully develop and produce the product. I was hoping to have it installed by the 2003 Tierra del Sol Desert Safari and now it looks like I will be able to for sure. I'll probably install it this weekend and I'll be sure to take pictures. Overall the kit looks cool even in the box and the instructions look fantastic. K&N provided step by step instuctions with a photo for each step. I like how they choose to put the filter on the drivers side since there is little else I'd want to put over there. On the TJ the filter sits on the passenger side and takes up room I'd use for an on board air compressor or something.

10/21/03: I've had the kit on for about 8 months now and love it. There is a noticeable whistle of air when accelerating but it's not very loud and I kind of like it. I have made one addition to this setup since installing it. I live in Arizona where it can be VERY dusty at times, especially when offroad. I bought a reuseable filter bag at Lowe's that was originally designed for a wet/dry vac. I threw away the packaging so I don't recall the size or product number but it fits pretty nicely without any clamps. The bag is reusable, cheap and slips over my K&N cone filter easily. See the pic below.

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What came with the kit	A "before" shot.	An "after" shot, with the old airbox in the background.	Overhead shot.
Precharger - you can see it gets dirty