To prove the performance potential of the mid-grade HPE650 package, Hennessey took the car to the drag strip and recorded some impressive times: zero-to-sixty mph in 3.9 seconds and a quarter mile run in 11.9 seconds at 124 mph.
To achieve those numbers, the HPE650 package includes a roots-type TVS2300 supercharger, a high-flow breathing system and Hennessey’s HPE engine-management calibration. The end result is 650 horsepower (up from 444 in the standard Boss), while the package will lighten one’s wallet to the tune of $15,995 with installation.
Hennessey is also offering a more financially-friendly starter kit, the HPE490, which raises the horsepower tally to 492 via cold-air induction, performance headers, a high-flow exhaust and the company’s engine-management calibration. Price is $3,995 if you’re brave enough to break out the tools and do it yourself, or $5,495 fully installed.
The truly power hungry should look into the HPE700, which makes a cool 700 horsepower. This range-topping package gets the same supercharger as the HPE650 with a pulley upgrade, an intercooler, a high-flow breathing system, a fuel-system upgrade, a strut tower brace and side exhaust. A $19,995 price tag gets you installation and proof that all the ponies are present and accounted for through dyno tuning.
Hennessey provides a 3 year/36,000 mile warranty on the two more potent upgrades (confusingly, the HPE490 only gets 1 year/12,000 mile coverage). All the performance extras imaginable, from heavy duty clutches to carbon fiber front splitters, are available as extras.
Watch a video of the HPE650 tearing up the drag strip below.