2015 Dodge Hellcat: Beyond Our Wildest Expectations

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Hellcat sideI will be the first to admit that the SRT division of Chrysler exceeded my boldest expectations with their 707-horsepower 2105 Dodge Hellcat coupe. That is not to say that the production SRT8 that has been offered since 2008 is tame, by any means. The SRT8 was already equipped with enough horsepower to qualify for a NASCAR sponsorship (470-hp) but the Hellcat takes factory produced muscle cars where they have never been before. The Hellcat car shuts down all of the blabber about the Ford/Shelby Mustang (662-hp) and the Chevrolet Camaro ZL1 (580-hp) and puts Chrysler firmly atop the heap when it comes to American made muscle. Let’s take a look at how they did it.


Hellcat engineStarting from the bottom — every good craftsman knows that you must have a firm foundation — the Street and Racing Technology (SRT) team at Chrysler proven themselves to be overachievers. Testing began with the 6.4-liter Hemi engine from the 2014 Dodge Challenger SRT8 with a focus on destroying the limitations for horsepower, previously realized by mere mortals. The bottom-end of the engine had to be stronger than conventional engine blocks to withstand the torque requirements of a supercharger and it had to run cooler in normal driving conditions. The result is a 6.2-liter Hemi engine design that is so state-of-the-art that it consists of ninety-eight percent newly designed parts. The unique engine block design features s specially developed configuration of cooling jackets that will allow the Hellcat engine to withstand excessive temperatures, while providing maximum heat dissipation properties. Finned aluminum cylinder heads are designed using lightweight construction to yield increased air flow. They are topped with exclusive aluminum rocker covers that are sure to be a hit with Mopar enthusiasts. The pistons and connecting rods are powder forged using heavier bushings and carbon coated wrist pins. The crankshaft is forged steel to handle the rigors often associated with forced air induction and balanced for maximum efficiency and durability. Crankshaft main bearing caps are also designed with a “four-bolt” design that is desired when building an engine to its maximum performance efficiency.


Hellcat superchargerA 2.3-liter twin-screw high-efficiency supercharger from IHI sits atop the massive beast of an engine. The supercharger provides a method of forced air induction that utilizes a belt driven pulley to turn a pair of rotors that are fitted together under extremely close tolerances . These rotors draw ambient air into the supercharger where it is compressed and forced into the intake passages and eventually the combustion chambers. Any engine which uses a supercharger must be specially built from the bottom up for maximum abuse. In addition to the increased air requirements placed on the engine by the supercharger, additional fuel must be supplied as well. SRT uses specially designed fuel injectors to deliver the correct mixture, as well as innovative and adaptive electronic strategies to provide optimum “streetability.”


engine sideviewIn a prime example of aesthetics contributing to athletics, the hood of the Hellcat is fully functional. The center scoop positioned in the center of the hood provides a constant supply of engine cooling air to the top of the motor and the front grille acts as an air dam to route a stream of cooling air to the front of the engine where an exclusive engine cooling intake routes it to hot spots. As the air exits the engine it is expelled through air vents flanking the center scoop. Seeking maximum thermal efficiency, the team at SRT designed an intercooler so large and sophisticated that it requires its own specially designed fascia. High beam headlights have been deleted on the Hellcat in order to allow an Air Catcher cold air intake to draw fresh air in from the outside. The unique low-speed engine cooling system helps the track focused car to function properly during low speed high-temperature stop and go driving. A high capacity water pump and air to oil engine oil cooler serve ensure that the powerful racing focused engine remains cool and well behaved during daily driving routines.


Air intakeThe engine also uses low restriction air intake and exhaust systems to maximize power output. The 2015 Dodge Hellcat boasts the first fully-active exhaust system to equip a Chrysler automobile. It provides manageable sound with a beautiful staccato note that opens up for less engine restriction when activated by the accelerator pedal. Under the hood, you can’t overlook the fact that the beautifully constructed stainless-steel exhaust headers look amazing.

Hellcat rearThe specially designed 8-speed automatic with steering wheel mounted paddle shifters, wider gears, and increased capacity clutches will handle the extra torque. Also available is a six-speed manual gearbox that is derived from the Viper. It uses an external cooling circuit and a upgraded clutch for increased durability.

A limited slip differential yields ultimate acceleration and cornering performance.

Hellcat wheelBringing this factory built race car to a halt is accomplished using a Brembo high-performance braking system. It features 15.4 inch Brembo rotors in a two-piece modular design in the front with 14.2 inch rotors in the rear. All four rotors are cross drilled and ventilated for maximum heat displacement. The brake calipers, which are highly visible through the specially designed Hellcat wheels are bright red; six-piston in the front and four-piston in the rear. This is the largest and most effective braking system ever used on a Chrysler vehicle.

So, there you have it. I am not afraid to admit when I am wrong and Chrysler got me with the whole “over 640-horsepower” quotation. I was thinking 650 or so, but thanks to more innovative minds, we have a 700+ horsepower American made sports coupe for well under $100,000.

S.M. Darby

S.M. Darby

I am a freelance author with over 25 years of experience as a professional, ASE certified automotive technician and shop owner, muscle car enthusiast, avid street racer, and classic car restoration specialist.