Included in the RK Series Tear Drop Kit is the cast aluminum backing plate, velocity stack
In the quest to make things go faster, look better, and just kick more ass altogether, we constantly strive to bring you the best-est products on the market. K&N Engineering continues to develop cutting-edge products that satisfy the aforementioned requirements, and has always been atop the performance game, especially when it comes to air filters. With a bevy of SKUs making up its inventory, one product in particular is quickly gaining recognition amongst gearheads—an easy upgrade at that—is the RK Series Tear Drop Air Cleaner ($249).
The Tear Drop Air Cleaner features an upgraded backing plate to flow air into the intake manifold/throttle body more optimally. Combine that with K&N’s iconic high-flow air filter—which pretty much put the company on the map—and you have a winning combination. Not to mention the fact that the new unit looks like a chrome piece of candy, shining brilliantly in all its glory against the cylinder fins. Also, K&N filters are covered by a million-mile warranty, so unless you plan on never working again and only riding your bike, you should be set. The Tear Drop kit fits ’99-07 fuel-injected Twin Cam engines. We encountered a 2006 Road King that was still in its stock state, if you can believe it, that definitely needed a little boost.
We were able to swap the stock air cleaner out with K&N’s Tear Drop quicker than a conversation with grandpa.
1. We started by removing the stock air cleaner cover, then taking off the stock filter, which the bike owner had obviously replaced recently. You could eat off that thing!
2. The crankcase breather tubes were removed, followed by the breather bolts, then ultimately the air cleaner backing plate was taken off.
3. Moving on to the new K&N backing plate, we installed K&N’s one-piece velocity stack, which allows more airflow than the stock application (above) . In the rear, these three holes are where the backing plate mounts to the throttle body (below).
4. Next, we installed the two provided spacers onto the backing plate with the provided hardware.
5. Using the stock breather bolts, we bolted the new backing plate to the cylinder head breathers while simultaneously tightening the velocity stack to the throttle body (we have four hands).
6. We slid the high-flow air filter in place and…
7. ... secured it with the new chrome cover. Simple, to the point, and subtle, the new unit looks great on the bike.
For shits and gigs, we had to see if K&N’s claims of 7-8 extra ponies were true with a test on the dynamometer. Sure enough they were. With the stock run of the 88ci mill, the bike produced 67hp and 68 lb-ft of torque. With the Tear Drop bolted in place, the better breathing engine produced 74hp and 75 lb-ft or torque. That’s an increase of 7 extra ponies and 7 lb-ft of torque in about 30 minutes.