The standard GT-R currently produces 542bhp
Nissan's executive vice president Andy Palmer confirmed he had driven the prototype in Japan, but declined to reveal technical details beyond saying it will be "the fastest GT-R ever".
The GT-R Nismo is known to have been developed with substantial input from Nissan's Nismo race team, which competes in the Japanese Super GT race series.
"The majority of the exterior changes are aero and downforce related," said Palmer. "The production car record at the Nurburgring is the gold standard, and we expect to lower that."
Although the Nissan Juke Nismo has only been given a minor power upgrade, and future mainstream Nismo products (including the 370Z) are expected to have changes focused on improving handling and cornering prowess, Palmer confirmed the GT-R Nismo will get a power boost over the standard 542bhp.
"There will be an extra kick," said Palmer. "This will be the ultimate GT-R to come out of the factory."