Hennessey Performance offered 12 special “Demon 1700 Twin Turbo” conversions. The project started with pulling the factory supercharged Demon V8 and wrapping it for storage. In its place Hennessey Performance installed a 440 ci (7.2L) Hemi V8 featuring a Dart iron block with 4.185-inch bore and 4.00-inch stroke. Inside are billet steel crank, forged steel rods, and billet aluminum pistons. Other upgrades include two Precision PT6870 turbochargers, twin water-to-air intercoolers, billet wastegates and BOVs, and stainless steel exhaust. Hennessey Performance upgraded the drivetrain with a Stage 3 automatic transmission with billet converter, upgraded driveshaft, and 3.09 ratio differentials. Hennessey Performance put a purple Demon 1700 on the dyno and made 1355 hp (996 kW) and 1202 lb-ft (1629 Nm) of torque to the wheels on 23 psi of boost.
Source: Hennessey Performance