Hennessey has been laying out packages left and right for a variety of models lately, including the Dodge Ram HPE500, Cadillac Escalade, and now, the lusciously tuned Nissan GT-R. There was no time wasted fiddling with the exterior of the GTR because Hennessey went straight to work pumping up the standard 3.8L V6 engine to produce up to 800 HP.
We haven’t seen this many additions under the hood of a vehicle since the last Hennessey tuned project we encountered, so we’re going to focus on some of the more important ones for now. The standard 3.8L V6 engine was jacked up with the help of SUMO turbo, intercooler piping, and intercooler core upgrades, as well as high-flow fuel injectors and chassis dyno tuning and engine calibration. Other additions include a SUMO stainless steel midpipe exhaust, SUMO stainless steel turbo downpipes, and a SUMO high-flow cold air induction. These modifications allow the GTR800 to pack an 813 HP punch and sprint the car from 0-60 mph in 2.6 seconds. The 0-100 mph sprint is made in 6.2 seconds and the quarter mile can be had for 10.5 seconds at a speed of 136 mph.[...]

Source: topspeed