Just when you think the muscle car era has reached its peak, John Hennessey and his Texas crew remind us why they’ve built a reputation for taking already-bonkers performance cars and launching them into the stratosphere. The latest victim is Dodge’s already-powerful Challenger SRT Demon 170, which Hennessey has transformed into a twin-turbocharged monster producing nearly 1,700hp.
The Hennessey Formula, Perfected
Hennessey Performance has been in the business of making fast cars faster for over three decades, but the Demon 1700 feels like something different. Where most tuners would toss in a bigger supercharger and call it a day, Hennessey took the more complex route by ditching Dodge’s 6.2L supercharged Hellcat V8 entirely in favor of a hand-built, 7.2L twin-turbocharged beast. The decision flies in the face of muscle car tradition (turbos on a Mopar muscle car?) but the results speak for themselves.
The transformation begins with a complete teardown of the Demon 170’s powertrain. Hennessey’s team blueprints every component before hand-building a new 440-cubic-inch HEMI V8 with forged internals, upgraded cooling systems, and a pair of massive PT6870 precision turbochargers. The result is an engine that produces 1,700bhp (~1,677hp) and 1,400lb.ft of torque on E85 fuel.
What’s fascinating about the build is how Hennessey managed to package all this hardware into the Demon’s existing engine bay. The twin-turbo setup required custom manifolds, upgraded fuel systems, new engine management, and a complete rethinking of the car’s cooling strategy. The attention to detail extends to components most people will never see, like billet engine mounts, custom V-band flanges, upgraded driveshafts, and a Stage 3 transmission capable of handling the additional torque.
Performance That Defies Logic
Numbers on paper are one thing, but Hennessey’s performance claims for the Demon 1700 border on the absurd. The company estimates a quarter-mile time of 7.9 seconds — a figure that would make it the fastest production-based car down the drag strip, eclipsing even purpose-built electric hypercars. To put that in perspective, the stock Demon 170’s 8.91-second quarter-mile time already puts most supercars to shame.
Along with improving its straight-line speed, Hennessey includes suspension modifications with billet control arms front and rear, ensuring the chassis can handle the additional power without becoming a liability. The company’s extensive testing regimen takes place at their in-house dynos and the Pennzoil Proving Ground at their Sealy, Texas headquarters.
The Hennessey Legacy
This isn’t Hennessey’s first rodeo with extreme horsepower. The company has been pushing boundaries since John Hennessey founded it in 1991, creating everything from 1,000-hp Vipers to the 1,817-hp Venom F5 hypercar. The Demon 1700 fits perfectly into this lineage, taking an already extreme vehicle and pushing it well beyond what anyone thought possible.
Spec Sheet
Model: Hennessey Demon 1700
Base Vehicle: 2023 Dodge Challenger SRT Demon 170
Engine: Hand-built 7.2L twin-turbocharged HEMI V8
Power: 1,677hp
Torque: 1,400lb.ft
Turbochargers: Twin Precision PT6870
Quarter-Mile: 7.9 seconds (estimated)
Transmission: Stage 3 automatic with billet torque converter
Limited Edition?: Yes, 12
Pricing & Availability
Limited to just 12 examples planned for production through Hennessey’s new Special Operations division, the Hennessey Demon 1700 upgrade package starts at $200,000, and that’s before you factor in the cost of a donor Demon 170, which will run you another $100,000 if you can find one. The company is currently taking inquiries for the remaining slots, with deliveries expected to begin shortly.
Recap
Hennessey Demon 1700
Hennessey puts a custom 7.2L twin-turbo HEMI V8 inside an already-powerful Challenger SRT Demon 170 to make it a 1,677hp hypercar with a 7.9-second quarter-mile time.
