Unleashing the Hellcat in Your Garage: The 600+ HP Dodge Charger 5.7 HEMI

The Dodge Charger 5.7 HEMI is a modern muscle car icon—a perfect blend of daily comfort and V8 fury. Right off the assembly line, this car delivers solid performance. However, for enthusiasts who demand more, the 5.7-liter HEMI has proven to be an incredibly capable platform for modification. With a methodical build plan, you can transform your Charger into a genuine 600+ horsepower street beast that outpaces many factory supercars. This guide walks you through every essential modification, from intake air to drivetrain upgrades, ensuring you achieve your horsepower goals while maintaining street drivability and long-term reliability.

Understanding the 5.7 HEMI: Capabilities and Limitations

Before spending a dollar on parts, it’s critical to understand what you’re working with. The third-generation 5.7 HEMI (found in 2006+ Chargers) is a robust engine, but it has specific bottlenecks that limit its factory output. The short-block is generally reliable up to around 550–600 wheel horsepower (whp). Beyond that, forged internals become a serious consideration. The biggest factory limitations are the intake manifold, camshaft profile, and restrictive exhaust manifolds. Additionally, the Multi-Displacement System (MDS), which deactivates cylinders for fuel economy, can be a reliability concern under sustained high load. Many builders delete MDS entirely during a cam swap for improved oiling and valvetrain stability.

Bottleneck Analysis: Where the Power Stops

  • Intake Manifold: The stock plastic intake restricts airflow above 5,500 RPM, starving the top end of air.
  • Exhaust: Cast iron manifolds and restrictive catalytic converters create excessive backpressure.
  • Fuel System: The stock fuel injectors and pump max out around 500–520 crank horsepower—far short of 600 hp.
  • Valvetrain: Factory valve springs are weak for aggressive cam profiles; they must be upgraded.
  • Transmission: The 5-speed automatic (NAG1) or 8-speed (8HP70) in later models can handle moderate power, but torque converter and clutch upgrades are needed for high-horsepower builds.

Stage 1: Breathing Mods – The Foundation for Power

Every high-horsepower engine needs to breathe efficiently. Start with these foundational upgrades before touching the camshaft or forced induction. They will also make your car more responsive during daily driving.

Cold Air Intake: The First Five Horsepower (and More)

A quality cold air intake system reduces intake air temperature and restriction. For the 5.7 HEMI, look for units that seal off the engine bay heat. Systems from AFE Power or K&N with a hydro-shield are excellent choices. Expect a gain of 10–15 whp on a dyno when combined with a tune. Pair the intake with a 85mm or 90mm throttle body to further improve airflow.

Cat-Back Exhaust System: Voice and Velocity

A cat-back exhaust system replaces everything from the catalytic converters back. Look for stainless steel mandrel-bent pipes (3-inch diameter) and free-flowing mufflers or resonators. Systems from Borla or Corsa provide excellent flow and an aggressive sound. Gains are modest—5–10 whp—but the weight savings and reduced backpressure set the stage for larger power adders. For maximum gains, consider adding long-tube headers and a full 3-inch exhaust, though this requires a tune adjustment.

ECU Tuning: Unlocking the Engine’s True Potential

ECU tuning is not optional. The factory calibration is tuned for emissions and fuel economy, leaving substantial power on the table. A custom tune via a handheld programmer like HP Tuners or DiabloSport InTune will optimize air-fuel ratio, ignition timing, and transmission shift points. For a 600+ hp build, you need a complete dyno tune or a remote custom calibration from a reputable tuner like HemiFever. A proper tune for intake/exhaust alone can add 20–25 whp and sharpen throttle response.

Stage 2: The Camshaft – The Heart of the HEMI

The factory camshaft in the 5.7 HEMI is relatively mild. To reach 600 hp, you need a performance cam with more lift and duration. This is where the real power gains happen. A cam swap also allows you to eliminate MDS if desired. Choose a camshaft matched to your goals and other mods—specifically, whether you plan to stay naturally aspirated or add a supercharger later.

  • Mild Street Cam (228°/228° @ .050"): Good for 450–480 whp with supporting mods. Requires upgraded valve springs and pushrods. Still has mild idle and good vacuum for brake boost.
  • Aggressive NA Cam (240°/252° @ .050"): Pushes toward 520–540 whp. Requires ported cylinder heads or aftermarket heads, a high-stall torque converter (if automatic), and upgraded fuel system. Idle is choppy; vacuum drops.
  • Supercharger Cam (218°/226° @ .050"): Designed for forced induction with lower overlap. For 600+ hp with a blower, a mild cam paired with a supercharger yields the best torque curve and drivability.

When installing a new cam, always replace the lifers (use non-MDS lifters if deleting MDS), valve springs, retainers, and timing chain set. A Comp Cams or Cam Motion grind is a safe bet.

Stage 3: Forced Induction – The Supercharger Route

The cleanest path to 600+ whp is a supercharger system. A centrifugal supercharger (like ProCharger or Vortech) or a positive-displacement blower (Whipple or Magnuson) can bolt onto a stock short-block and safely produce 600–650 whp with proper tuning and supporting fuel mods. For the 5.7 HEMI, a Paxton 2200SL or Vortech V3 Si on 7–9 psi with an intercooler is a popular combination.

Complete Supercharger System Components

  • Supercharger head unit (centrifugal or twin-screw)
  • Intercooler (air-to-air or air-to-water)
  • Fuel system upgrade: 1,000+ cc injectors, dual in-tank pumps, boost-reference fuel pressure regulator
  • Bypass valve for part-throttle drivability
  • Custom tune for forced induction (must be done on a dyno)

With a supercharger, even a near-stock long block can hit 600 whp reliably as long as you limit boost to 7–8 psi and keep the engine cool. Beyond that, consider forged pistons and rods.

Supporting Mods: Keeping the Beast Reliable

Making power is easy; making it last is the challenge. The following supporting modifications are essential for a reliable 600+ hp build.

Fuel System Upgrades

The stock fuel system must be upgraded. At minimum, install 52–60 lb/hr fuel injectors (if supercharged, go to 80 lb/hr or larger). The factory pump may need to be swapped for a Fore Innovations triple-pump system or a single Walbro 525. A boost-reference fuel pressure regulator ensures the engine gets enough fuel under boost.

Cooling System

Higher power = higher heat. Upgrade to a high-flow aluminum radiator (e.g., Mishimoto or Griffin), a 180°F thermostat, and an external engine oil cooler. For supercharged builds, a larger intercooler heat exchanger is vital. Consider a water-methanol injection system for intake charge cooling—it also adds knock resistance.

Drivetrain: Transmission and Differential

The 8-speed 8HP70 is stout but will need a performance torque converter with a higher stall speed (2,600–3,200 RPM) to keep the engine in the powerband. For the 5-speed NAG1, upgrade the valve body and install a deep transmission pan with cooling fins. The rear differential should be treated to a LSD rebuild with stronger clutches, or swap to a limited-slip unit. Axles may need upgrading at 600+ whp to avoid breakage during hard launches.

Suspension and Tires

All that power is useless if you can't put it to the ground. Install adjustable lower control arms, upgraded sway bars, and firmer shocks. A set of sticky tires (305/35R20 or 275/40R19 on drag radials) is mandatory. Weight reduction (remove spare tire and rear seats) also helps traction.

Dyno Projection and Realistic Expectations

With a full stage 1 (intake, headers, exhaust, tune) and a stage 2 cam (aggressive NA), you can expect 470–500 whp. Adding a supercharger (7 psi) with supporting fuel and cooling pushes that to 580–620 whp. With a forged bottom end, higher boost (10–12 psi), and ported heads, 650+ whp is achievable. Always get a baseline dyno pull and then final calibration after each major upgrade to monitor air-fuel ratios and knock retard.

Budget Considerations

Build costs vary widely:

  • Intake/exhaust/tune: $1,500–$2,500
  • Cam swap + supporting parts (valvesprings, pushrods, lifters, tune): $2,000–$3,500
  • Supercharger kit (installed and tuned): $6,000–$9,000
  • Fuel system upgrade: $800–$2,000
  • Transmission upgrade: $1,500–$3,000
  • Subtotal for 600+ hp build: $12,000–$20,000 (including installation labor if not DIY)

Final Thoughts: Building a Cohesive Street Beast

A 600+ horsepower Dodge Charger 5.7 HEMI is an attainable and rewarding project. The key is to plan your platform holistically—choose your cam and supercharger combination first, then work backward through supporting mods. Never skimp on tuning or cooling. When executed correctly, your Charger will deliver neck-snapping acceleration, a menacing exhaust note, and the confidence to challenge just about anything on the street or track. Whether you daily drive it or reserve it for weekend thrills, a properly built 5.7 HEMI is a testament to the enduring appeal of American V8 performance.