Tuning a twin-turbo, 480-horsepower V-6-powered AWD sports car might seem like an exercise in futility - after all, where are you going to open it up - but when you look beyond the street and to the race track, it becomes a bit more reasonable. And for those that like to spend their weekends pushing their skill and equipment to the limits, Switzer Performance's latest Nissan GT-R is an intriguing toy. Today's update brings confirmation of the 850 horsepower crank rating and more details on the car, including a dyno plot.

The standard P800 Nissan GT-R manages its name-giving 800 horsepower at the crank on standard 93-octane pump gas, but some owners and enthusiasts wanted to see what Switzer could do when higher octane race gas was used. Switzer was happy to oblige, as the video below demonstrates.

"We've bent a bit to the demands of those customers that are using their GTRs primarily as trackday cars, and developed a new 'R' package specifically for them," said Tym Switzer.

Hitting a delivered 740 horespower and 715 pound-feet of torque at the wheels, the car earns its R850 name, with an estimated 850 horsepower at the crank based on a pretty standard assumption of 15% drivetrain loss.

Switzer explained: "We're seeing consistent dyno results in excess of 740 all-wheel-horsepower and 715 pound-feet, pull after pull. Most everyone seems to agree that the GTR has about a 15% driveline loss. Based on that, this kit is making well over 850 horsepower and 820 pound-feet at the crank."

But enough talk - check out the video to see for yourself what it sounds like when 850hp is uncorked in an enclosed space. Hint: it's loud.


Switzer R850 Dyno Plot

Switzer R850 Dyno Plot

Switzer's R850 Nissan GT-R hits the dyno