A 5.7 Hemi upgrade kit adds performance parts to your Dodge or Jeep engine, but the scope and price depend heavily on which components you choose

The 5.7-liter Hemi V8 engine comes stock in Dodge Ram trucks, Dodge Chargers, Jeep Grand Cherokees, and other vehicles. An upgrade kit is not a single product — it is a collection of aftermarket parts designed to increase horsepower, torque, or both. Common additions include a cold air intake, performance exhaust system, tuning software, and internal engine modifications. The cost ranges from under $500 for basic bolt-on parts to $5,000 or more for comprehensive builds that include cylinder head work or forced induction.

Before buying any kit, you need to know what your engine currently produces and what you want it to produce. Stock 5.7 Hemi output varies by year and vehicle — a 2009 Ram produces different numbers than a 2020 Charger. You also need to decide whether you want to keep your warranty intact, because most engine modifications void manufacturer coverage on powertrain components.

Key Takeaways

  • A 5.7 Hemi upgrade kit is a collection of parts, not a single product, and different kits target different goals: fuel economy, horsepower, or towing capacity.
  • Bolt-on parts like intake and exhaust systems cost $500 to $1,500 and require no engine disassembly, while internal modifications cost significantly more and require professional installation.
  • Engine tuning software (a reflash or ECU tune) often comes bundled with kits and can add $300 to $800 to the total cost.
  • Most engine modifications void your manufacturer warranty on the engine and transmission, so confirm what coverage you lose before purchasing.
  • Professional installation is strongly recommended for anything beyond basic bolt-on parts, and labor costs typically run $500 to $2,000 depending on complexity.

Bolt-On Parts: The Entry Point for Most Builders

Bolt-on upgrades are parts you can install without removing the engine from the vehicle or disassembling internal components. The most common are cold air intake systems, which replace the factory air box with a larger intake tube and a high-flow filter. These typically cost $150 to $400 and claim to add 5 to 15 horsepower. A performance exhaust system — headers, mid-pipe, and muffler — runs $400 to $1,200 and is often sold as a complete kit. Exhaust work usually adds 10 to 25 horsepower and improves throttle response.

Spark plugs, ignition coils, and fuel injectors are also bolt-on replacements. Upgrading to colder-running spark plugs or higher-flow fuel injectors costs $200 to $600 and is sometimes included in a larger kit. Many builders start with intake and exhaust because these parts are reversible — you can remove them and reinstall the factory components if you sell the vehicle or want to restore warranty coverage for that section.

Engine Tuning Software and ECU Reflashing

A tuning software update, also called an ECU reflash or chip tune, reprograms the engine control unit to adjust fuel timing, ignition timing, and boost pressure (if forced induction is present). This is where most of the power gain comes from in a complete kit. A reflash alone costs $300 to $800 depending on the tuner and whether it is a generic tune or custom-tailored to your specific vehicle and modifications.

Popular tuning platforms for the 5.7 Hemi include Diablosport, SCT, and Superchips. Many kits bundle a reflash with bolt-on parts and sell the combination as a package. The tuning software is not reversible in the same way a physical part is — reverting to stock requires another reflash, which costs money and may not be possible if the tuner goes out of business or stops supporting your model year.

Forced Induction: Superchargers and Turbochargers

If you want substantial power gains — 100+ horsepower — you need forced induction: either a supercharger or turbocharger. A supercharger is belt-driven by the engine and bolts to the intake manifold. A turbocharger uses exhaust gases to spin a turbine and is mounted in the exhaust system. Supercharger kits for the 5.7 Hemi range from $4,000 to $7,000 installed, while turbo kits typically cost $3,500 to $6,000.

Forced induction requires supporting modifications: upgraded fuel injectors, a higher-capacity fuel pump, engine tuning, and often internal engine work like forged pistons or reinforced connecting rods. The total cost for a complete forced induction build often exceeds $10,000 when labor is included. These upgrades also increase engine stress and heat, so cooling system upgrades (radiator, intercooler, fans) are usually necessary.

Internal Engine Modifications and Machine Work

Serious builds include cylinder head porting, valve upgrades, camshaft swaps, and internal strengthening. Porting the cylinder heads — reshaping the intake and exhaust ports to improve flow — costs $800 to $2,000 per head and requires removing the heads from the engine. A performance camshaft upgrade runs $400 to $1,000 for parts plus $500 to $1,500 in labor. Forged pistons and connecting rods, used to handle higher boost pressure or nitrous oxide, cost $1,500 to $3,000 installed.

These modifications require professional machine shop work and engine disassembly. They are not reversible without significant expense and are typically only done when building an engine for racing or extreme performance. Most street drivers do not need internal modifications — bolt-on parts and tuning deliver usable gains without the cost and complexity.

Installation Labor and Where to Have Work Done

Bolt-on parts like intake and exhaust can be installed by a competent DIY mechanic with basic tools in a few hours. Professional installation at a shop typically costs $200 to $500 for a complete bolt-on package. Engine tuning software is usually done remotely or at a tuning shop and takes 30 minutes to 2 hours, costing $300 to $800 as noted above.

More complex work — forced induction installation, cylinder head work, or internal engine modifications — requires a shop with Hemi-specific experience. Labor for a supercharger installation alone can run $1,500 to $3,000. Shops that specialize in Dodge and Jeep performance, such as those affiliated with brands like Mopar or independent performance shops, are your best option. Always get a written estimate before work begins and ask whether the shop warrants its labor.

Warranty and Reliability Considerations

Dodge and Jeep warranty coverage explicitly excludes damage caused by aftermarket parts or modifications. Installing a cold air intake or exhaust system will not void your entire warranty, but if an engine failure occurs and the manufacturer determines that your modifications contributed to it, they can deny the claim. Forced induction and internal modifications carry much higher risk — most dealers will refuse to service an engine with a supercharger or turbo under warranty.

Reliability depends on the quality of the parts and installation. A well-designed bolt-on kit from a reputable manufacturer (such as Mopar performance parts or established aftermarket brands) rarely causes problems. Cheap or poorly designed kits, or installations done incorrectly, can lead to overheating, fuel system issues, or premature engine wear. Research the specific kit and installer before committing money.

Frequently Asked Questions

How much horsepower will I actually gain?

Bolt-on parts (intake and exhaust) typically add 15 to 30 horsepower. Adding tuning software can bring the total to 40 to 60 horsepower. Forced induction adds 100 to 200+ horsepower depending on boost level and supporting modifications. Actual gains vary based on your vehicle's year, condition, and how well the parts work together.

Can I install a 5.7 Hemi upgrade kit myself?

Bolt-on parts like intake and exhaust are DIY-friendly if you have basic mechanical skills and tools. Tuning software requires a laptop and tuning software license but no mechanical work. Anything involving forced induction, cylinder head work, or internal engine modifications should be done by a professional shop.

Will an upgrade kit hurt my fuel economy?

Performance exhaust and intake systems have minimal impact on fuel economy. Aggressive tuning software can reduce economy by 1 to 3 miles per gallon if you drive hard. Forced induction typically reduces economy by 2 to 5 mpg. Driving habits matter more than the kit itself — spirited driving burns more fuel regardless of modifications.

What is the difference between a supercharger and a turbocharger?

A supercharger is belt-driven and provides when ready power but uses some engine power to operate. A turbocharger uses exhaust gases and is more efficient but has a slight delay (turbo lag) before it reaches full boost. Superchargers are easier to install on the 5.7 Hemi; turbochargers are less common but offer better fuel economy under light throttle.

Do I need to upgrade my fuel system for a basic bolt-on kit?

No. The stock fuel pump and injectors handle basic bolt-on upgrades without issue. If you add tuning software or plan forced induction later, you will need a fuel pump upgrade and larger injectors. Plan ahead if you think you might upgrade further down the road.