Screamin' Eagle® Performance
What kind of performance is right for me and my bike? Screamin’ Eagle® Stage upgrades offer complete street-compliant performance configurations engineered to generate specific torque and horsepower gains. Eliminating all the guesswork and trial-and-error testing normally associated with engine modifications, Stage upgrades include everything you need to enhance your bike’s performance. You can start with key components that give you a bump in power right now, add components as time and budget permits, or you can go for it all at once.
INTAKE + EXHAUST + TUNING: Simply put Pipes, Breather and a tune. Stage I is the easiest and most cost effective step to improve your motorcycle’s performance. A high-flow air cleaner and system-matched slip-on mufflers provide horsepower and torque improvements you can feel throughout the RPM range, and serve as the core components for all performance upgrades. ECM calibration is required to tune the fuel flow and timing required to accommodate the improved air flow.
As an example on our new Milwaukee 8 you can expect a 5-10% increase through the entire RPM range with the Screamin' Eagle Stage I. This is achieved using the Heavy Breather, the all new 4.5" street cannons and our newly redesigned Pro-Street tuner. Stage I upgrade can be installed without engine disassembly. No special tools are required. Requires ECM tuning.
STAGE I + CAM UPGRADE: Adding a performance cam to a Stage I equipped bike is the next step to improved performance. Cam choices allow you to tailor the engine’s performance to your specific needs. A “torque” cam offers on-demand throttle response from low- to mid-RPM at cruising speed. A “power” cam targets high-rpm, wide-open throttle response that keeps pulling right up to redline. ECM calibration tuning is required to accommodate the increased valve timing, and performance valve springs may be required for high-lift cams. Milwaukee 8 ( Torque kit ) uses a SE447 cam and you can expect a 14% increase in torque off the line over and above Stage I. Milwaukee 8 ( power kit ) uses a SE462 cam to show a 24% increase from 3000RPM to redline over and above the 5-10% of the stage I
Stage II upgrade requires minor engine disassembly to replace the cam. Adjustable pushrods allow cam installation without removing the rocker box. Special tools and ECM tuning are required.
STAGE II + BIG BORE CYLINDERS & PISTONS: The next step on the performance journey is to build a “bigger” engine. An increase in engine displacement allows the engine to swallow more air and fuel, a higher compression piston squeezes the air/fuel into a more volatile mixture, and when combined, generates more power when ignited. A displacement and compression increase provides torque increases throughout the entire RPM range with a 15-25% improvement in the mid-range power. ECM calibration tuning is required to adjust fuel flow and timing to accommodate the increased displacement.
107-114ci ( Milwaukee 8 ) 39% increase in power and torque over stock 107ci 114-117ci ( Milwaukee 8 ) 24% Increase in power and torque over stock 114ci ( both kits include a SE 498 cam). Stage III “bolt-on” upgrade requires removal of the engine’s top-end and opening the cam chest. Engines bottom end remains in the frame and no machining is required. Special tools and ECM tuning are required
Stage III + BIG BORE CYLINDERS & PISTONS + HEADS: Take it up another notch with the Screamin’ Eagle Stage IV. Available for Twin Cam models in "street" or "race" versions. This is the go big or go home performance upgrade. By increasing air and fuel flow even more coupled with high compression pistons this upgrade is a force to be reckoned with. With a new set of CNC ported heads , a 58mm Throttle body SE 259E cams and high flow injectors you can expect a real noticeable increase in HP and TQ. The warranty compliant 103ci "street" version of this kit can have you ahead of the pack by producing 105 ft lbs of torque and up to 98 HP @ 5500RPM.
With the "race" version you can expect even more performance. Available for both air cooled and Twin-cooled Twin Cam H-D Engines.