4 Things to Know about Harley’s Screamin’ Eagle Upgrades

Performance In Stages

Over the years, Harley-Davidson's Screamin' Eagle performance kits have proven to be incredibly popular upgrades among owners, and for good reason - they're designed with parts that work perfectly together and give owners choices in terms of just how far they want to go. Currently, there are four Screamin' Eagle kits available - Stage I through Stage IV - each providing its own unique parts and giving owners the chance to upgrade over time, too. Here's what you need to know about each before plunking down your hard-earned cash. 

Photos: Harley-Davidson

Stage I

First up, we have the Stage 1 Screamin' Eagle kit, which consists of an upgraded intake, exhaust, and tune, and is designed to give owners a simple bolt-on performance upgrade that enhances the looks, performance, and sound of a motorcycle. Stage 1 customers can also choose from a variety of intakes and exhaust systems to fit their own style and desire for sound, too. 

Photos: Harley-Davidson

Stage II

Moving up to Stage II gives owners everything present in Stage I, plus a camshaft upgrade. Customers have choices on how they want their power delivered as well - either a torque cam that offers on-demand throttle response from low to mid RPM at cruising speed, or a power cam, which targets high RPM, wide-open throttle response that keeps pulling right up to the redline. 

Photos: Harley-Davidson

Stage III

The Stage III kit starts to get more serious by including big bore cylinders and pistons, which adds power throughout the rev range. This kit is designed to produce instant passing power out on the road without the need for downshifting, and it delivers excellent stoplight to freeway and on-ramp acceleration as well. 

Photos: Harley-Davidson

Stage IV

Finally, we have the Stage IV upgrade, which throws in upgraded cylinder heads and a bigger throttle body for even more power. The Stage IV kit is designed to maximize the impact of the increased displacement gained with Stage III updates, the addition of free-flowing CNC ported cylinder heads, and a big bore throttle body, making for the ultimate in factory-added performance. 

Photos: Harley-Davidson

>>Join in on the conversation about these upgrades here in Harley-Davidson Forums.

For help with your do-it-yourself maintenance and repair projects, please visit our how-to section in the forum.