Harley Davidson Sportster: Air Cleaner Kit Reviews and How to

This article applies to Harley Davidson Sportster models.

The air cleaner is in place to filter the air of any harmful contaminants that would otherwise enter the engine. A quick look at the modern Sportster's air cleaner assembly will leave many scratching their heads and wondering how the engine is able to operate with such a restricted intake path. Due to noise and emissions requirements, the stock air cleaner only draws air from a small orifice at the bottom of the air cleaner cover. The paper filter element further restricts airflow, as the engine must pull air through a slim 1.5" filter height. Needless to say, swapping to a new air cleaner assembly with improved flow characteristics can greatly improve the performance and ride-ability of the Harley-Davidson Sportster. The following article will outline the steps involved in installing an air cleaner kit, followed by a review of several popular kits available on the market.

Table of Contents

• How to Replace Your Air Cleaner
• Featured Videos
• Air Cleaner Kit Review

How to Replace Your Air Cleaner

Step 1 – Remove stock air filter cover

Using a 3/16" Allen wrench, remove the (2) bolts securing the air filter cover in place. Harley uses Threadlocker on these fasteners, so they may take a good amount of force to break them loose. With the bolts removed, the model badge and filter cover can be slid off, then set aside.

Step 2 – Remove filter element

With the filter cover removed, the air filter element is now accessible. Remove the (3) Torx fasteners and remove the filter element from the bike.

Step 3 – Remove backing plate

• The filter backing plate and throttle body are now exposed (see Figure 2). The backing plate is held in place with (2) bolts. Using a ratchet and 9/16" socket, remove the backing plate bolts before sliding the backing plate off of the bike. The throttle body gasket will typically remain in place on the backing plate or throttle body. Be sure your new air cleaner kit includes a new gasket before discarding the old one.
• Depending on which aftermarket air cleaner kit is being installed, the support bracket may need to be replaced with a new bracket. If you application calls for bracket removal, simply remove the socket head fastener with the appropriate size Allen wrench.

Step 4 – Install new air cleaner kit

• Install the new support bracket onto the throttle body (if applicable).
• Install backing plate onto the support bracket using all hardware supplied in the air cleaner kit. Ensure the throttle body gasket is properly placed between the backing plate and throttle body. Apply Blue Threadlocker to the backing plate bolts/breather bolts and tighten to the manufacturer's specification. (HD torque spec: 120-144 in/lbs)
• Install the air filter element and torque the fasteners to the manufacturer's specification. (HD torque spec: 55-60 in/lbs)
• Install air filter cover and apply Blue Threadlocker to the fasteners. Torque the fasteners to the manufacturer's specification. (HD torque spec: 36-60 in/lbs).

Step 5 – Calibrate ECM

Fuel injected Harleys require the ECM to be remapped to take advantage of the additional airflow the engine will be receiving. While debates rage as to whether or not tuning is needed for a simple aftermarket air cleaner swap, Harley and various tuners suggest that the engine can suffer from a lack of fueling and lead to a lean condition when installing aftermarket performance parts. Various tuning kits are available to allow individuals to make engine mapping adjustments based on their modifications and increase performance. Not only can tuning the ECM provide peace of mind that the engine will be running safe and reliably, but it is a nice tool for any performance enthusiast that has plans for future performance modifications.

Featured Videos: Air Cleaner Install

• Screamin' Eagle Stage-1 Air Cleaner Install

• DK Custom Air Cleaner Kit Install

Air Cleaner Kit Review

Perhaps one of the most cost-effective solutions to increasing the performance of your Sportster is an aftermarket air cleaner kit. As previously mentioned, to meet modern EPA noise and emissions standards, the stock air cleaner assembly tends to be very restrictive and leaves a fair bit of performance on the table. There are a variety of aftermarket kits available to relieve the congestion in the intake tract and allow for better airflow to your Sportster's engine. As the old saying goes, more air plus more fuel equals increased horsepower and torque. If you are looking to begin modding your Sportster, an air cleaner kit is a great platform to build upon. Several popular air cleaner kits are outlined below to give a general idea of the options available when choosing a kit for your bike.

	Screamin' Eagle Stage 1	Screamin' Eagle Heavy Breather	Küryaken Hypercharger	Vance & Hines VO2	DK Customs Outlaw
Price	$144.95-149.95	$329.95-500.00	$199.00-299.00	$139.95-239.95	$148.95-194.95
Performance Gain	10%	12%	Claimed 7-9 Horsepower	5-7 Horsepower	11%
Use stock filter cover	Optional	No	No	No	No
Washable filter element	Yes	Yes	Yes	Yes	Yes
Available finishes	Black, Chrome, or Stock	Black, Chrome, Black with Chrome Accents	Chrome, Black, Accented Butterflies	Uncovered, Chrome, Matte Black, and Gloss Black	Uncovered, Chrome, Black, and Custom Emblems

Screamin' Eagle Stage 1

Price – $144.95-149.95

Performance Gain – 10%

Uses Stock Filter Cover – Optional

Washable Filter Element – Yes

Available Finishes – Black, Chrome, or Stock

Screamin' Eagle branded products are Harley-Davidson's official performance parts that are engineered specifically for your bike. Many individuals prefer Screamin' Eagle (SE) parts over offerings from other aftermarket companies due to their quality, fit, and finish. Not to mention, who better to develop performance parts than the engineers who designed the bike in the first place? The SE Stage 1 filter kit is offered in two configurations, a round and oval kit, with the latter being able to use the stock filter cover to keep the bike looking original. Nearly all air cleaner kits come with a washable high flow filter element, and produce similar performance gains, so selection often comes down to their visual appeal. With a Harley-backed warranty and top notch quality, this kit is recommended for the enthusiast looking to keep original quality H-D parts on their bike.

Screamin' Eagle Heavy Breather

Price – $329.95-500.00

Performance Gain – 12%

Uses Stock Filter Cover – No

Washable Filter Element – Yes

Available Finishes – Black, Chrome, Black with Chrome Accents

Arguably the hottest looking filter kit on the market, Harley's SE Heavy Breather setup places the filter away from the bike and into clean air for the ultimate boost in performance. Claimed to be a step up from the Stage 1 kit, the Heavy Breather is designed to create a ram-air effect at speed as well as force air through the curved intake tube and directly into the throttle body. Various filter covers are available to further enhance its visual appeal, but beware of rain, as this kit has been know to ingest water. H-D offers a filter sock as shown above to repel water in wet conditions without hindering performance. Although this kit is as expensive as it gets, most agree that the aesthetics combined with the increased performance boost make this kit worth every penny. This kit is recommended for the individual looking for top notch performance and aggressive looks with little regards for its hefty price tag.

Küryaken Hypercharger

Price – $199.00-299.00

Performance Gain – 7-9 Horsepower

Uses Stock Filter Cover – No

Washable Filter Element – Yes

Available Finishes – Black, Chrome, Accented Butterflies

One of the largest manufacturers of aftermarket parts for all H-D platforms is Küryaken. Their Hypercharger line of air cleaner kits mimic the look of injector hats that are found on top fuel drag cars. Using vacuum operated butterfly valves, the design is often a talking point between individuals that either love it or hate it. While many agree that their claimed performance increases are a bit optimistic, this air cleaner kit does free up airflow to the intake for a respectable power boost. A number of owners have experienced problems with the butterfly valves and simply locked them in the open position at all times. Not for the faint of heart, the Hypercharger kit is best suited for the individual who wants to stand out from the rest of the crowd.

Vance & Hines VO2

Price – $139.95-239.95

Performance Gain – 5-7 Horsepower

Uses Stock Filter Cover – No

Washable Filter Element – Yes

Available Finishes – Uncovered, Chrome, Matte Black, and Gloss Black

No review would be complete without a product from performance specialists, Vance & Hines. Vance & Hines have long been involved in various types of two-wheeled motorsports competition and they use their data gathered on track to improve road-going bikes for the true performance enthusiast. Like other kits, the VO2 uses a washable filter element, but differs in its use of a fairly large backing plate and CNC billet-machined Venturi. This kit can be run with the filter element exposed, or fancied up with a selection of covers. In any case, this is a versatile kit that is recommended for individuals looking for a good jump in performance at relatively entry-level pricing, with the ability to add accessories at a later time.

DK Customs Outlaw

Price – $148.95-194.95

Performance Gain – 11%

Uses Stock Filter Cover – No

Washable Filter Element – Yes

Available Finishes – Uncovered, Chrome, Black, and Custom Emblems

At the other end of the spectrum is relatively small company DK Customs. Priding themselves on customer satisfaction, DK Customs offers their Outlaw air cleaner kit that uses a round K&N high flow air filter and custom backing plate as a means of improving performance. The Outlaw kit has proven some impressive gains despite a lack of fancy air cleaner housings or air deflector shields. This kit can be run with a plain cover (as shown), uncovered, or with a variety of custom covers offered by DK in black or chrome finishes. Recommended if you are looking for a good old-fashioned/functional air cleaner kit.

Related Discussions

• Screamin Eagle Stage 1 vs Heavy Breather Air Filter- HDForums.com
• DK Customs Outlaw HighFlow Air Cleaner System - HDForums.com
• Sporster Air Filters...Stock or Aftermarket Which is Best? - HDForums.com
• Remapping a 2011 Sportster?- HDForums.com
• Performance Gains With Heavy Breather? - HDForums.com