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707 horsepower was a revolution when the SRT Hellcat first hit the pavement. Today, in the world of modern muscle, it is simply the baseline. If you own a Dodge Charger or Challenger Hellcat, you already command one of the most formidable machines ever built in Detroit. But the factory tune is conservative. The hardware is over-engineered. The potential for more is staring you in the face.
Pushing a Hellcat past the 800HP mark: specifically toward that 800–850 wheel horsepower (WHP) range: requires more than just turning up the dial. It requires a calculated strategy that balances increased boost with superior fueling and aggressive cooling. At DTX Performance, we don't just sell parts; we provide the blueprint for dominance.
This is your guide to safely unlocking the true monster lurking under your hood using the best performance car parts online.
Build the Foundation: The 800HP Objective
Before you start ordering parts from a modern muscle performance parts shop, you must define your goal. Are you looking for 800 crank horsepower or 800 wheel horsepower?
Stock Hellcats typically put down roughly 630–650 WHP. To jump into the 800+ WHP territory, you are looking at a 150+ horsepower increase. This level of power puts significant stress on your fueling system and creates immense heat. To do this safely, you cannot skip steps. You must address the "Big Three": Boost, Fuel, and Cooling.
Increase the Boost: The Supercharger Pulley
The 2.4L IHI supercharger sitting on top of your HEMI is a workhorse, but the factory pulley is sized for reliability across all climates and fuel qualities. To get to 800HP, you need more boost.
Select Your Pulley Size
The most common path to 800HP involves swapping the upper supercharger pulley. A ZPE Grip-Tech 2.85" pulley is the industry standard for this transition.
- The Science: By shrinking the pulley size, you increase the blower speed relative to the engine RPM.
- The Result: A 2.85" pulley typically adds 3–4 PSI of boost over stock.
- The Edge: Grip-Tech technology uses micro-machined surfaces to prevent belt slip, ensuring that every ounce of energy from the crank reaches the blower.
Don't Forget the Pin
If you are increasing boost, pinning the crank is non-negotiable. The stock Hellcat crank pulley is not keyed; it is a press-fit design. Under the increased torque of a high-boost setup, the pulley can spin on the snout of the crank, leading to catastrophic engine damage. Always use a high-quality pinning kit during your pulley upgrade.
Fuel the Fire: Injectors and Pumps
You can shove all the air you want into the combustion chamber, but without a corresponding increase in fuel, you will run lean. Running lean at 800HP is the fastest way to turn your HEMI into a boat anchor.
High-Performance Injectors
Stock Hellcat injectors (approximately 600cc) max out quickly once you move to a smaller pulley. To safely push past 800HP, you need to upgrade to high-impedance injectors with a higher flow rate.
- Fuel Injector Clinic (FIC) 1000cc or 1200cc: These are the gold standard for Hellcat builds. They provide the overhead necessary to maintain a safe duty cycle even at wide-open throttle.
- Demon/Redeye Injectors: For those looking for a "factory-plus" approach, stepping up to the 750cc injectors found in the Demon or Redeye can support high 700s, but for a true 800+ WHP build, FIC is the superior choice.
Fuel Pump Considerations
On 93 octane pump gas, the stock dual-pump setup can usually handle the 800HP threshold. However, if you plan to run E85: the "cheap race gas": you will need a dedicated fuel pump voltage booster (like a Kenne Bell Boost-A-Pump) or a complete drop-in triple-pump system. E85 requires roughly 30% more volume than gasoline, making fueling upgrades even more critical.
Manage the Heat: Cooling Upgrades
Heat is the natural enemy of the Hellcat. As you increase boost, the air charge temperature (IAT2) skyrockets. When the ECU sees high temperatures, it pulls timing to protect the engine, which kills your power gains. To stay at 800HP consistently, you must stay cool.
Upgraded Heat Exchangers
The factory heat exchanger is efficient for stock levels, but it heat-soaks rapidly under back-to-back pulls. Upgrading to a dual-pass or larger surface area heat exchanger is mandatory. This helps dissipate heat from the intercooler fluid before it goes back into the supercharger lid.
Spacers and Thermal Blankets
Reducing "knock" and heat soak can also be achieved through physical barriers.
- Supercharger Spacers: These sit between the blower and the cylinder heads, reducing heat transfer from the engine block to the supercharger.
- Thermal Blankets: Wrapping the lower intake or the supercharger lid can help keep engine bay heat from soaking into the air charge.
The Interchiller Option
For the ultimate cooling setup, many Hellcat owners look toward an Interchiller. This system taps into your car's A/C refrigerant to chill the intercooler fluid to sub-ambient temperatures. It is the most effective way to ensure 800HP is available every time you hit the pedal, regardless of the weather.
Let It Breathe: Exhaust Systems
Backpressure is a power killer. While the factory Hellcat exhaust is surprisingly high-flow, a high-boost setup benefits greatly from reduced restriction.
High-Flow Headers
Long-tube headers are one of the most significant "supporting" mods you can install. By improving the scavenging effect, headers allow the engine to exhale more efficiently, which can actually lower boost pressure slightly while increasing total horsepower. It makes the engine more efficient.
Cat-Back Performance
If you want that signature aggressive tone alongside your power gains, upgrading the rear section is a must. For those running the 6.2L supercharged platform, the AWE Tuning 2015 Dodge Charger 6.2L Track Edition Exhaust offers a straight-through design that eliminates the heavy factory resonators, providing a raw, unfiltered V8 scream.
Shop the AWE Tuning 2015 Dodge Charger 6.2L Track Edition Exhaust to give your 800HP build the voice it deserves.
Tune for Precision: The Brain of the Build
None of these parts mean anything without a proper tune. Dodge ECU/PCMs are locked from the factory. To push past 800HP, you must:
- Unlock the PCM: Send your factory PCM to a specialist or buy a pre-unlocked unit.
- HP Tuners: Utilize the HP Tuners platform to calibrate the air/fuel ratios, timing maps, and shift points.
- Custom Tuning: Do not rely on "canned" tunes. Every Hellcat reacts differently to mods. A custom remote or dyno tune from a reputable HEMI tuner is the only way to ensure your 800HP build is safe and reliable.
Safety and Reliability Mods
Power is useless if you can't put it to the ground or if you break parts in the process.
- Tires: Stock 275 or 305 street tires will not hold 800HP. You will need a dedicated drag radial like the Nitto NT555RII or Mickey Thompson ET Street S/S to make the car usable.
- Driveshaft: The stock two-piece driveshaft is a known weak point. Upgrading to a one-piece aluminum or carbon fiber driveshaft is highly recommended for any car hitting the drag strip.
- Oil Catch Can: High boost means more crankcase pressure. A catch can prevents oil vapor from being fed back into your intake, keeping your valves clean and preventing detonation.
Shop with Confidence at DTX Performance
Building an 800HP Hellcat is a journey. It requires precision-engineered parts and an uncompromising commitment to quality. As your premier automotive performance shop online, DTX Performance is dedicated to providing the components you need to transform your modern muscle car.
We understand the thrill of the build and the necessity of reliability. Whether you are searching for fuel injectors, pulleys, or high-performance exhaust systems, we have the inventory to get you to the finish line.
Select Your Path
- Push the limits.
- Build the dream.
- Shop DTX Performance.
Ready to start? Browse our full catalog of modern muscle performance parts and take the first step toward 800HP today. We promise to only send you the good things: the parts that actually make you faster.
