John Hennessey and his Hennessey Performance Engineering tuning outfit have prepared a little something for owners of Chrysler Group SRT-8 cars and SUVs from the 2011 to 2013 model years fitted with the brand's 6.4-liter HEMI V8 engine.
The first one is named HPE600 and includes a raft of upgrades highlighted by a TVS2300 supercharger system, an ECU recalibration, new fuel injectors and a custom air induction system to boost output from 470bhp to 600bhp at 5,500 rpm.
For an extra charge, customers can opt for the HPE650 kit that comes with a slightly more aggressive tune, which adds new cylinder headers and high-flow catalytic converters, allowing the 6.4-liter V8 to produce 650bhp at 5,800 rpm.
If that's not enough, there's always HPE's twin-turbo conversion for the HEMI engine, which pushes out 800bhp at 6,200 rpm.
All engine conversions can be accompanied with a raft of optional upgrades for the transmission, exhaust and braking systems as well as the exterior and interior of the SRT-8 models.