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The Evolution of the Dodge Hellcat Supercharged V8 Engine

The HEMI engine has a convoluted history and two controversial moments when Chrysler Australia and Mitsubishi offered six- and four-cylinder mills under this nameplate. The almighty Hellcat, by comparison, has followed the same formula since its first application for the 2015 model year.
Dodge Hellcat Supercharged V8 Engine 44 photos
Photo: Dodge
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Named after a carrier-based fighter aircraft used by the U.S. Navy and Marine Corps in World War II, the Hellcat shares the 103.9-millimeter bore with the 6.4-liter HEMI and the 90.9-millimeter stroke with the 5.7-liter HEMI. But nevertheless, the majority of components are redesigned or new.

When Dodge rekindled the muscle car wars, the Hellcat used to develop an unprecedented 707 horsepower and 650 pound-feet (881 Nm) of torque, which is a lot even by modern standards. The 6.2-liter displacement makes sense from the standpoint of durability, and the 3.58-inch stroke offers key advantages over the 3.72-inch stroke of the 6.4-liter HEMI. These are increased crank overlap, taller compression height, and reduced compression (9.5:1 vs. 10.9:1) to support a thumpin’ great blower from IHI.

Regulated at 11.6 pounds per square inch of boost, the 2,380-cc supercharger is a twin-screw affair instead of the Roots-type units that General Motors and Ford Motor Company use in the Chevrolet Camaro ZL1 and Shelby GT500. Sealed for life from the factory, the IHI supercharger has a 2.36:1 step-up ratio and tops 14,600 revolutions per minute.

The high air-mass flow was a prerequisite when Dodge selected the Japanese company over competing suppliers, and the supercharger is packaged together with the intake manifold and intercooler. A 92-mm throttle body feeds the gargantuan powerplant with air, and the intercooler keeps the inlet air temperature below 140 degrees Fahrenheit (make that 60 degrees Celsius) under extreme driving scenarios such as track days as per Dodge.

Dodge Demon Supercharged V8 Engine
Photo: Dodge
Every single Hellcat goes through a dyno test before shipping to ensure that everything works as intended, and customers are offered a total of two cog-swapping options. A six-speed manual in the guise of the Tremec TR-6060 opens the list with two-piece gears and laser-welded clutch teeth rings. The other transmission is the venerable 8HP from ZF Friedrichshafen, which has been continuously developed since its launch in the F01 BMW 7 Series.

After the Challenger SRT Hellcat and Charger SRT Hellcat, the peeps at FCA have adapted the 6.2-liter supercharged engine for the Jeep Grand Cherokee Trackhawk. Sources within Stellantis understand that a brand-new Grand Cherokee Trackhawk isn’t going to happen because of the ever-draconic emissions regulations and Groupe PSA’s push for electrification, which is why the WK2 with this mill has the makings of a modern classic.

Once the most powerful series-production SUV in the world, the GCT has been surpassed for the 2021 model year by the Dodge Durango SRT Hellcat by only three horsepower. The only problem with the Durango in this configuration is the rarity, as in rarer than the insane Demon.

The most exciting muscle car there’s ever been launched for the 2018 model year in a limited run of 3,300 units of which 3,000 were sold in the United States of America. Not exactly a Hellcat with more boost, the Demon-spec V8 motor features 62 percent redesigned or newly-developed componentry.

Manufactured in Ramos Arizpe, Mexico where Hellcats continue to be made, the Demon is rocking a stronger block, reinforced main caps, a high-flow gerotor pump, cooling jets that spray twice as much oil, and a lubrication system that can withstand acceleration forces as high as 1.8 Gs.

Dodge Hellcat Supercharged V8 Engine
Photo: Dodge
The rotating assembly and fuel system are thoroughly different as well, along with the fuel system’s compatibility with 100-plus octane and 2.7-liter supercharger instead of the original 2.4-liter unit. When fitted with the high-performance dash switch bank and powertrain control module, the Demon delivers a simply unbelievable 840 horsepower and 770 pound-feet (1,044 Nm) of tire-scorching twist. Opting for 91-octane premium unleaded sees those numbers drop to 808 horsepower and 717 pound-feet (972 Nm).

For the 2019 model year, the Demon was indirectly replaced by the Redeye. This variant of the Hellcat produces 797 horsepower and 707 pound-feet (959 Nm) because it features a street-friendly tune with a dual-snorkel hood instead of the air-grabber induction system of the strip-slaying Demon. The Challenger and Charger in Redeye flavor have the 2.7-liter supercharger, and they rev to 6,500 rotations per minute instead of 6,200 for the Hellcat.

Introduced last year, the 2020 Dodge Challenger SRT Super Stock is the most recent entry in the Brotherhood of Muscle. Tuned for 807 force-fed ponies and the same torque rating as the Redeye, this fellow is closer to the Demon because it features 315/40 by 18-inch drag radials supplied by Nitto.

Currently the world’s quickest and most powerful muscle car, the Challenger SRT Super Stock differs from the Demon in a few notable ways. Engineered for premium gasoline instead of race fuel, this version doesn’t feature a Transbrake and the Drag Mode has been replaced by Race Mode.

I have to end this article on a sorrowful note, though. “The days of the iron-block supercharged 6.2-liter V8 are numbered,” said Tim Kuniskis, the big kahuna of Dodge and the gentleman who headed the SRT performance division when the Hellcat came out. The Challenger and Charger will be redesigned in 2024, and their successors will reportedly feature a hybridized transmission from ZF Friedrichshafen connected to more frugal V8s.

2024 is also the year the Dodge brand will reinvent itself with an all-electric muscle car that Stellantis teased last month at the EV Day event.
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About the author: Mircea Panait
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After a 1:43 scale model of a Ferrari 250 GTO sparked Mircea's interest for cars when he was a kid, an early internship at Top Gear sealed his career path. He's most interested in muscle cars and American trucks, but he takes a passing interest in quirky kei cars as well.
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