Supercharger Showdown: Roots vs. Twin-Screw vs. Centrifugal for the HEMI

# Supercharger Showdown: Roots vs. Twin-Screw vs. Centrifugal for the HEMI

Adding a supercharger is the single largest power upgrade you can make to a naturally aspirated 2022 Dodge Challenger. But when you start shopping, you quickly discover that "supercharger" isn't one thing — there are fundamentally different designs that deliver power in completely different ways.

Understanding the distinction matters because the type of supercharger you choose will change how your car feels to drive every single day. This guide breaks down every type.

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How Superchargers Work: The Core Principle

All superchargers do the same thing at a high level: compress air and force more of it into the engine. Denser air means more oxygen per combustion cycle, which means you can burn more fuel, which means more power.

The difference between types is how they compress air. And that "how" creates dramatically different power delivery characteristics.

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Roots-Style Supercharger

How it works: Two counter-rotating rotors with lobed profiles mesh together and push air through the housing in discrete pockets, like an air pump. Unlike a true compressor, the air isn't actually compressed inside the blower — it's pushed at atmosphere pressure into the manifold, where it collides with the higher-pressure air already there and compresses at the intake ports.

Power delivery: Immediate. Full boost available from idle, since the roots blower moves a fixed volume of air per revolution regardless of RPM. You get maximum torque right off the line.

Sound: The traditional blower whine. The meshing rotors create a characteristic high-pitched moan that increases with engine speed. It's the sound of classic American hot rods.

Heat: More heat-generating than a twin-screw or centrifugal. The air is pushed rather than compressed, which is thermally less efficient. Intercooling is important.

Efficiency: Lower thermal efficiency than twin-screw or centrifugal. Requires more power to drive (more parasitic drag on the engine).

Example: Edelbrock E-Force is a roots-type design. The factory Hellcat Eaton TVS (technically twin-vortices Series — a modern roots variant) is also in this family.

Best for: The classic supercharged muscle car experience. Big, immediate torque. Outstanding for street driving and drag launches.

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Twin-Screw Supercharger

How it works: Two counter-rotating helical (spiral) rotors mesh together like giant screws. Air is trapped between the rotors and the housing wall, and as the rotors turn, the air is compressed inside the housing before it exits. This internal compression makes it meaningfully more efficient than a roots design.

Power delivery: Like roots, boost is available immediately from low RPM. The power curve is broad and flat — tractable, linear, relentless.

Sound: Similar distinctive whine to a roots, but often slightly higher-pitched and more mechanical-sounding. The Whipple's sound is well-loved by enthusiasts.

Heat: Lower discharge temperature than roots. The internal compression is more thermally efficient. Still benefits from intercooling, but cooler charge temps translate to more power potential.

Efficiency: Best of the positive displacement types. Lower parasitic drag than roots for the same boost output.

The dominant Challenger option: Whipple (Gen 5 3.0L) and Magnuson (TVS2650, TVS2300) are twin-screw units and represent the majority of positive displacement supercharger builds on the HEMI.

Best for: Street, drag, daily driver. The best of all worlds for positive displacement — efficiency, power, torque, and sound.

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Centrifugal Supercharger

How it works: A high-speed impeller (like a turbocharger's compressor wheel) spins inside a housing. Air is drawn in, accelerated by centrifugal force, and compressed by the diffuser that converts velocity to pressure. Unlike positive displacement designs, boost pressure scales with the square of rotational speed — meaning it builds dramatically with RPM.

Power delivery: Progressive. Little boost at low RPM, building through the powerband to peak boost near redline. The car feels like a naturally aspirated engine at low RPM, then hits like a freight train as RPM climbs.

Sound: Turbo-like whistle that builds with boost. Not the traditional supercharger whine — more like a turbo car, which some people love and others don't.

Heat: Most thermally efficient supercharger type. Less parasitic drag. Produces less heat in the charge air.

Efficiency: Highest of the three types at high RPM. Best top-end power per unit of displacement.

Examples: ProCharger P-1SC-1 (most popular HEMI centrifugal), ProCharger D-1SC (higher output), Vortech V-3 Si.

Best for: Track use, top-speed builds, drag racing (where the power builds exactly where the RPM is high). Less ideal for street driving where you want immediate torque at partial throttle.

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Side-By-Side Comparison

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Real-World Power Numbers (6.4L Scat Pack, Complete Kits)

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Which Type Should You Choose?

Choose a Twin-Screw (Whipple / Magnuson) if:

• This is primarily a street car
• You want immediate, tractable power when you press the throttle
• You want the classic supercharger sound and feeling
• You drive in traffic and want power below 3,000 RPM
• You value the best combination of power, sound, and street manners

Choose a Centrifugal (ProCharger / Vortech) if:

• You spend significant time at a track or drag strip
• You want maximum top-end horsepower at high RPM
• Your car has traction issues — the progressive power delivery is easier to manage on slippery surfaces
• You want a less intrusive look (centrifugal mounts at the front, not on top of the engine)

In the Challenger community, the vast majority of street builds choose twin-screw (Whipple in particular) for its combination of torque, sound, and immediate response. Centrifugal builds are popular among track-focused owners.

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What Every Type Has in Common: The Safety Rules Don't Change

Regardless of which type you choose, the safety requirements are identical:

1. Fuel injectors sized for your boost level — mandatory
2. Upgraded fuel pump — mandatory
3. Custom ECU tune — mandatory, no exceptions
4. Colder spark plugs — mandatory
5. Cooling management — strongly recommended

And the Complete Kit vs. Tuner Kit distinction applies to all types. Buy a Complete Kit unless you already have an existing custom fuel system.