Rubicon Giveaway: K&N Aircharger Install

Clearing The Air: Installing a Freer Breathing K&N Aircharger on our Giveaway 2005 Jeep Unlimited Rubicon

story & photos by Steve Temple

Having already added a suspension lift and bigger wheels and tires, we’re off and running with the buildup of our giveaway Jeep Unlimited Rubicon. But as we pick up the pace, we’re breathing harder and now need to open up the engine’s lungs with a K&N Aircharger.

This particular upgrade has been available for Jeep’s 4.0 inline-six engine for some time, so it has a solid history of improving performance with only a modest investment of time and money. Previous dyno tests indicate an increase of more than 12 hp at 4623 rpm, but that can vary somewhat with the age of the vehicle.

The stock air intake system is a tad quieter, but at the expense of some power output.

The K&N Aircharger creates a slightly higher engine sound, but looks and performs way better.

In our case, the Jeep Rubicon is so new that it had only a couple hundred miles on the engine. K&N says that it likes to see a thousand or more miles of break-in time to optimize the power output before adding a high-flow induction system. No surprise, then, that our baseline readout was only 130 hp, about 17 hp lower than K&N’s previous tests on a stock 4.0 engine. The larger tires may have somewhat impacted the power readout at the wheels as well.

On the other hand, the power gained by adding K&N’s high-flow intake kit was fairly consistent. We didn’t quite achieve the claimed 12 hp, but came pretty close at almost 11 hp. Over time we can expect to see some slight improvement as the engine opens up.Bolting on a K&N Aircharger is pretty simple. Even if all you know is how to change a tire or just a light bulb, you can still handle this job. Figure on being able to do it in just a couple of hours using just a few common hand tools. And once it’s done, you’ll definitely breathe easier.

Buy K&N Air Filters from www.4wheelparts.com.

Components of K&N’s high-flow intake kit consist of a filter element, heat shield, air tube and mounting hardware.		1. Start by detaching the crankcase vent hose and removing the top section of the factory air intake, which exposes the stock air filter. On later model Jeeps, you’ll also need to carefully remove the Inlet Air Temperature (IAT) sensor (save it for re-installation on the K&N intake).
2. Note the difference in the pleats between K&N’s filter (left) and the stock filter. The K&N’s are obviously more open, and the element is longer as well.		3. Next, unbolt and remove the lower section of the factory intake.
4. Fit the supplied gasket material on the edge of the K&N heat shield. You’ll need to trim off the last few inches to get the ends to meet.		5. After attaching mounting brackets, fit the heat shield assembly into the same location as the factory air box, and secure it to the rubber-insulated studs provided with the kit.
6. Install the flexible silicone hose section.		7. If your Jeep engine comes with an IAT sensor, drill a hole in the K&N tubing and re-install the sensor.
8. Install the K&N intake tube into the heat shield and intake manifold.		9. Plug in the wiring for the IAT sensor.
10. Re-attach the crankcase vent hose.		11. Install the filter and tighten the clamp, and you’re done. Wasn’t that easy?