TL;DR

Unlock your Harley's true potential with Screamin’ Eagle® performance upgrades, from Stage I to Stage IV. Each stage offers increasing power, torque, and throttle response—backed by Harley’s warranty-friendly engineering. Find the right fit for your ride and lifestyle.

• Stage I – Intake, exhaust, and tune: better sound, response, and up to 10% more power.
• Stage II – Cam upgrade: torque or horsepower boost tailored to your riding style.
• Stage III – Big bore kit: more displacement, more compression, and up to 35% performance gain.
• Stage IV – Full top-end build: max out power, flow, and Harley-Davidson performance.
• Warranty-safe – Screamin’ Eagle kits protect your factory coverage.
• Costs range from $1,000 (Stage I) to $10,000+ (Stage IV), depending on parts and labor.
• Designed by Harley, for Harley—no compatibility headaches.

If you’ve ever said “No thanks” to more torque and horsepower, you might not be riding a Harley‑Davidson®. Since the beginning, H‑D® has been about that adrenaline rush you get when power meets throttle. For many, the journey doesn’t end with stock performance—riders want more. That’s where Harley Stages come in, especially the official Screamin’ Eagle series.

Before you dive in, here’s what you need to know.

These Harley Screamin’ Eagle upgrades are designed by Harley itself. They’re engineered to play nice with your bike’s factory setup. And—if done through Harley’s programs—they often don’t void your powertrain warranty.

The streets get louder, the curves get tighter, and your ride gets more character. The only real question is: How much power do you want?

Here's the basics of what you'll be getting with each upgrade stage:

Stage I – Move More Air & Fuel

What Is Harley Stage 1 Upgrade?

Harley Stage 1 upgrades kick things off with breathability. In simple terms, this means installing a high‑flow air filter or air cleaner and swapping in freer‑flowing exhaust or slip‑on mufflers. It also means re‑tuning the engine (ECU or ECM flash/tuner).

With Stage 1, you’re improving how your Harley handles air in, fuel delivery, and exhaust flow. This all gives you that growl, that pull, and an all‑around more responsive ride. This level of upgrade is perfect for anyone wanting solid gains without opening up the engine.

It’s one of the most popular Harley stages.

Performance Gains & Feel

• Expect about 5‑10% increase in horsepower and torque depending on your specific Harley model.
• Throttle response sharpens, the exhaust note deepens, and even everyday acceleration (off the line, passing) gets noticeably better.
• Visual appeal: upgraded air cleaners, slicker pipes, and those signature Harley Screaming Eagle parts add style.

Harley Stage 1 Upgrade Cost

• Parts for a Stage 1 kit often run $1,000 to $1,500 for quality components.
• If you pay for professional installation and tuning, add extra—labor can add several hundred dollars more.
• Doing it yourself helps cut cost, if you have basic tools and mechanical comfort.

Stage II – Give It a Lift

What Is Stage 2 Harley Davidson Upgrade?

Once you’ve done Stage 1 (if you want full gains), Stage II goes deeper. You start modifying internal components like the camshaft, adjustable pushrods, sometimes lifters.

The goal? Shift the performance curve: more torque in specific RPM bands (low‑to‑mid or mid‑to‑upper), depending on your riding style. That means better passing power, stronger roll‑on throttle, more aggressive breath; basically lifting the ceiling.

What To Expect in Stage II

• Choose a “Torque” Stage II cam for punch off the line or a “Power” Stage II cam for higher revs.
• Increased valve lift/duration lets you squeeze more from each combustion cycle.
• You’ll want matching hardware: pushrods, maybe upgraded lifters or springs, and of course proper tuning.

Cost & Considerations

• Stage 2 upgrade kits themselves (cam/pushrod etc.) often cost $400‑$600 or more depending on brand and model.
• Labor can add significantly: cam installation is more involved, may require 5‑8 hours depending on your bike.
• Total Stage II cost often lands in the $1,000 to $1,500+ range (parts + labor + tuning) if done professionally.

Stage III – Pump Up the Volume

What is Stage III Harley Performance?

Stage III is when you start pushing displacement, compression, and internal upgrades. Think big bore kits, high compression pistons, stronger valves, aggressive cam profiles, and upgraded heads. This is for riders who want serious numbers and aren’t shy about engine work. These modifications move you well beyond bolt‑ons.

Performance & Trade‑Offs

• Gains of 25%‑35%+ over stock in many cases — depending on how aggressive parts are.
• Far superior high‑RPM performance, much stronger mid‑range too.
• More heat, more maintenance, may require upgraded cooling, stronger drivetrain components, possibly clutch upgrades.

Investment Required

• Parts alone can run $1,600‑$2,500 or more depending on how much displacement and which brands you go with.
• Add labor: since you're opening up the engine, machine work is needed. Expect hundreds of dollars more depending on the shop.
• Tuning becomes even more critical to make sure you don't damage the engine, especially under load or at high revs.

Stage IV – Top it Off

What Does Stage IV Harley Stage Do?

This is the top shelf, the “cherry on top” stage. With Stage IV you’re combining everything:

• maximum displacement,
• highest compression,
• top‑end flowing heads,
• possibly larger throttle bodies,
• performance cam, and
• every supporting piece you need (fueling, ignition, cooling, stronger drivetrain, etc.).

Harley Stage IV upgrades are for riders who want the absolute best in Harley‑Davidson performance and are ready to pay for it.

Gains, Experience & Commitment

• Huge pull: off the line, mid‑range, and upper RPM — this is serious performance on tap.
• Loud, aggressive sound. Way higher performance means you’ll feel everything: vibration, engine heat, maintenance intervals shorten.
• Can push beyond what stock support systems are designed for. You need high‑flow fuel, maybe upgraded oil pump, upgraded cooling, etc.

Harley Stage 4 Upgrade Cost

• The cost for this level is quite substantial. Parts + labor + tuning + supporting mods can run $3,000‑$10,000 or more depending on how extreme you go.
• Reliability and rideability need extra attention. Stage IV is commitment: for serious riders who plan to use the power and maintain it.

Which Stage Is Right for You?: Putting it All Together

• If you ride mostly street and maybe some highway— Stage I gives you big gains for relatively little investment.
• Want more torque/power in certain RPMs (for passing, hills) — Stage II might be your sweet spot.
• For long rides, open roads, performance feels in every gear — Stage III gives you that next‑level punch.
• If you want to show off, drag off the line, go full throttle, push the limits — Stage IV is where it gets wild

Final Thoughts: Power Is Personal

Harley‑Davidson makes it easy to find your level of performance. Whether you’re just wanting an earful of rumble (Stage I), or dreaming of owning a Stave IV beast, the journey is modular. Start where you are, plan where you want to be, and let each stage build on the last.

Riding is about confidence, and when your bike responds to your will — that’s freedom. Choose the stage that matches your riding life. Then, twist the throttle and feel it.

At Southside Harley-Davidson, we know performance isn’t just a number—it’s a feeling.

Whether you’re chasing more torque, craving that deep rumble, or ready to unleash the full potential of your ride, rely on Southside. Our team is here to help you build it right with genuine Harley Screaming’ Eagle® performance upgrades. From Stage I to Stage IV, we’ll make sure your Harley delivers the kind of power that moves you—on and off the road.

Browse our collection of Harley-Davidson motorcycles here.

Indiana weather can sometimes be tricky to predict, but this morning was a dreadful reminder that colder weather is most certainly on the way. For many motorcyclists, this first annual encounter with the morning frost can often mean that it's time to start thinking about sending the baby into hibernation until spring rolls around. But still, there are quite a few riders out there who aren't ready to submit to the winter wrath quite yet- and it's A-okay to keep riding through the season, as long as it's done safely. 

The Cold, Hard Truth.

First, we need to acknowledge the dangers and risks associated with riding in the cold. If you've ever journeyed out into the brisk, fall breeze unprepared, you were likely quick to regret not tuning in to Fox59 that morning for the weather. Not only is riding in the cold extremely uncomfortable without proper gear, but your body and mind are also at a significant disadvantage when your body temperature drops. Even if you think you're feeling good, colder temperatures will often result in:

• Shivering
• Slower reaction times
• Impaired judgement
• Low energy
• Stiff joints and muscles

All of which make you a hazard to yourself and others out on the road. Of course, the last thing we, at Southside Harley, would ever want to do is discourage anyone from riding. So, with enthusiastic support for our die-hard riders out there, we've thoughtfully assembled a list of riding tips that will help you stay safe and warm, should you choose to motor through the bitter days ahead.

Tips For Riding Safely In The Cold

1. Choose Your Underwear Wisely

Wearing thermal underwear will help your body retain heat in all the places that matter. This will help you stay warm without the need to layer on several additional pieces of clothing that may restrict your body's movement while riding. We recommend The Harley-Davidson® FXRG Base Layer Pant and Base Layer Tee. These under-layers from the FXRG Collection were designed with some pretty incredible smart technology that actually help to regulate your body's temperature.

Check out the video for more information about the FXRG Under Layer:

See the full FXRG Collection for HERE (in-store availability may vary)

2. Invest In The Gear That Matters

Sometimes there are benefits to spending a few extra bucks on good quality gear that is actually designed for riding. You can throw on your thick, toasty pair of snow-blowing gloves, but will your hands and fingers be nimble enough to operate your controls?

Treating yourself to a proper riding jacket will also help make those cold rides quite a bit easier. The material you choose for your jacket is typically a matter of preference. Some riders will say that a waterproof, textile jacket will be your best bet to keep you warm without restricting your movements. But Harley-Davidson has introduced some pretty wicked innovations to their leather jackets which make them a mentionable option, as well.

Check out some of the recommended cold weather gear we've got in stock at Southside Harley!

3. Stay Hydrated

Unlike the summer time, we don't always thirst for water when it's cold outside. That can become a problem if we don't recognize that our bodies still need water to function at 100%. Make sure you drink plenty of water before and during your ride. 

4. Skip The Morning Joe

Coffee is a great way to start a crisp, winter morning- but not necessarily if you're planning on riding. It may hit the spot and warm your spirits, but drinks like coffee increase your blood flow to the skin to make you feel warmer, but you're actually losing body heat. Best to stick with water or drinks with electrolytes to keep you truly hydrated for the ride. 

5. Eat Like A Champ

Because our metabolism slows down when it's cold, our body begins to shiver to generate heat inside of us. Eating hardy, nutritional foods will keep you warm while calories are burned. Foods with anti-oxidants and immune-boosting properties will help you feel warm while you ride. While eating hot foods make you feel warm in the moment, a piece of fruit can be just as beneficial, if not more.

6. Stop Frequently

If you're planning on being on the road for a while, make sure to make plenty of stops to warm yourself up. Taking breaks will give you the chance to stretch out and get the blood flowing through your body again. Take this time for a quick self-assessment of how your fingers and toes are feeling. If you can, try to stop at rest stops along your route to use hand dryers in the restrooms to warm your fingers. 

You May Spend More, But It Won't Cost As Much

In the end, making the decision to ride through the winter- or at least for some colder months- takes a bit of preparation and, yes, perhaps a little bit of money. But your rides will be much more tolerable and- dare we say- enjoyable. By committing to a few upfront expenses and inconveniences, you're actually investing in the safety of yourself and others out on the road- and that's something we can all afford.