Hennessey actually offers three different levels of tune for the new Challenger SRT8. The first two stages, developing 500 and 530hp respectively, rely on a series of breathing mods for the increase in output. The range topping SRT700, meanwhile, gets a custom turbocharging kit, engine stroker upgrade, forged internals, high-flow injectors, a dual 3in exhaust system and ECU mod. The end result is 725hp at 5,200rpm and 1,016Nm (750lb-ft) of torque from 4,000rpm.
Other features include high-flow cylinder heads, stainless steel piping, a 44mm wastegate, front mount intercooler and a 3.5in polished inlet tube blow-off-valve.
Officials claim the car will reach 60mph from rest in just 3.5 seconds, pass the quarter mile in 11.3 seconds at 126mph and go on to reach a top speed of 190mph. Hennessey will also dyno test the car to guarantee the output, and even offers a one year limited warranty in case something goes wrong. Since Hennessey is still yet to release pictures of its modified Challenger, pictured above is the standard production SRT8 model, which you can read about by clicking here.