Hennessey has announced it has created an even more powerful version of Jeep's already mighty Grand Cherokee Trackhawk.
The base HPE850 Upgrade raises power from the standard Trackhawk's supercharged 6.2-litre V8 from 527kW/874Nm to an incredible 635kW/1146Nm
If that's not enough, the Texan tuner will also offer a HPE1000 package that boosts power even further to a herculean 755kW/1314Nm.
This has had a dramatic effect on performance, with Hennessey claiming that post-mods, the big heavy SUV is capable of hitting 60mph (97km/h) in just 2.8 seconds -- a huge improvement over the Trackhawk's benchmark-setting 3.6sec 0-100km/h time.
Liberating the additional power and torque has required extensive under bonnet tinkering including a larger supercharger, upgraded fuel injectors, new high-flow fuel pump, revised exhaust and cold air intake.
Hennessey hasn't confirmed pricing for the performance upgrade but it's thought the HPE1000 upgrade could weigh in as much as $US50,000 ($A65,000) on top of the $134,900 Jeep charges for the Grand Cherokee Trackhawk in Australia.
Back in the US, if you opt for the Hennessey performance upgrade each car comes with a before and after dyno certificates, is subjected to more than 300km shakedown testing and comes with a one-year/20,000km warranty.
It's not known if Hennessey plans to offer the performance upgrades globally as a retrofit option, which could see it eventually head Down Under.