Screamin' Eagle Stage 1 Upgrade WHY? The Harley Tax; no kidding--that's what it's called.  It's the price that owners must pay if they want their bikes to perform like they should have from the factory.  With the machines being produced by the competition it would seem that Harley-Davidson would sell  a "big twin" that produced more than 60 horsepower at the rear wheel; that's pretty anemic for a bike weighing 700+ pounds.  Compared with the rest of the world's motorcycle population, Harley-Davidson big twins are painfully slow, and most owners make modifications to perk them up a bit.  The first step in adding power is called (go figure) the Stage 1 Upgrade, and consists of a more free-flowing exhaust system, a less-restrictive air cleaner, and a change in carb jetting or a re-programming of the ECU to keep the proper air/fuel ratio so that the bike won't run in a lean condition and suffer engine damage.  A different exhaust is the first order of business for most; if it can't be fast, at least make it loud!  I don't like the racket produced by most aftermarket exhausts, but after a great deal of experimentation I settled on the Screamin' Eagle Pro torque mufflers; you can find more information about them here.  There are several choices available to upgrade the air cleaner but I decided on the Screamin' Eagle Stage 1 kit (part #29773-02B).  This kit replaces the stock air cleaner with one that flows better; the result is an air/fuel ratio that is too lean, a situation that must be remedied by re-jetting the carburetor or changing the ECM's fuel map on injected models.  On my FI Softail I had a number of options:  the most popular are 1) a dealer-performed download that re-calibrates the ECU, 2) the Screamin' Eagle Race Tuner, which allows the owner or tuner to fine-tune the fuel map, or 3) aftermarker units such as the Dynojet Powercommander PCIII that alter the ECU's signals to change the fuel map.  I considered the Harley race tuner to be an attractive option, but since I currently plan no more engine mods I opted for the Stage 1 download (dealer-installed for $78--more on that later).  The list price on the air kit is $139, but I found it on Zanotti's web site for $108 plus shipping and I placed the order. SERVICE.  Excellent.  After ordering I received a confirmation email from Zanotti's parts department; the next day I received a notification that they had the item in stock and would ship immediately.  I received an email the next day notifying me that it had shipped.  The box arrived at my door via UPS ground four days later.  I've done a great deal of shopping online, and I believe that Zanotti's service is about as good as I've seen; other vendors would do well to take note.  The kit arrived well-packed and undamaged; installation instructions were included. INSTALLATION. The instructions and diagram were fairly easy to understand, and the average home mechanic should be able to handle this installation.  The entire process took me less than 15 minutes.  I knew that the new air cleaner would make the bike run very lean and I didn't want to chance any engine damage by riding it the 30 miles to the dealer for the ECU re-calibration so I trailered the bike to the shop.  The list price for this work is $149 but my dealer did the job for $78 since I had purchased the bike from him.  After a 30-minute wait I was on my way. RESULTS.  Really nice--it's incredible what a difference this one modification can make.  The new intake is a bit more noisy, but the bike now has noticeably more pull through the entire power band.  It may just be my imagination, but it sure seems that it runs smoother at all speeds and it definitely cruises better on the highway with the extra horsepower.  The Screamin' Eagle torque mufflers were just a bit too loud for me, so I removed them in favor of the stock pipes.  Some folks might say that the stage 1 air cleaner upgrade is no good without performance exhaust, but don't believe it; the bike is pulling much stronger with just the new intake and ECU download.  Worth the money?   Absolutely.  I've gained quite a bit of performance for under $200.