This isn't even Hennessey's top tune of the Trackhawk.

Hennessey is once again showing off the impressive performance of its HPE1000 upgrade package for the Jeep Grand Cherokee Trackhawk. The supercharged SUV doesn't lack for power from the factory, and these tweaks take the output to ludicrous extremes.

As the only all-wheel-drive model that is currently available with the 6.2-litre supercharged Hellcat V8, the Grand Cherokee Trackhawk exhibits incredible acceleration off the line. Hennessey's upgrades make the launches even more brutal. The firm installs a 4.5-litre supercharged running at 14 psi of boost. New fuel injectors and an upgraded fuel pump make sure that the upgraded powertrain gets plenty of petrol. There's also a high-flow air intake for sending plenty of oxygen to the blower. The setup is enough to beat a new Ford GT off the line at least until higher speeds give the supercar an aerodynamic advantage to gain on the boxy SUV.

According to Hennessey, the upgrades push the Trackhawk's output to 1,012 bhp and 969 pound-feet of torque. It can hit 60 mph in 2.7 seconds and cover the quarter mile in 10.7 seconds. The company's dyno tested a Grand Cherokee configured to be rear-wheel drive with these bits and found figures at the road of 839 bhp and 759 lb-ft. 

If a Trackhawk owner wants even more power, Hennessey can help, too. The company's HPE1200 package boosts the engine to 1,200 bhp and 1,000 lb-ft on 109 octane petrol. The dyno shows 1,003 bhp and 892 lb-ft at the wheels. It covers the quarter mile in 9.66 seconds.