Buff books and online outlets began publishing 0-60 runs between 3.2 and 3.4 seconds, and quarter-mile times began dropping quicker than a co-ed's IQ on a nitrous binge. CARandDRIVER.com discovered a similar discrepancy between five different GT-Rs and finally decided to get some time on the dyno to get some real-world numbers.
CARandDRIVER's first tester ran to 60 in 3.3 seconds and past the traps in 11.5 seconds at 124 mph, causing C&D's scribes to suspect that Nissan engineers cranked up the boost on the evaluation vehicle. Shortly thereafter, two more GT-Rs arrived at their offices, both recording significantly slower quarter mile times and confirming their suspicions. Unfortunately, time constraints prevented either vehicle from getting up on the rollers. That would have to wait until Tony Swan returned with his GT-R after campaigning in the One Lap of America.
Surprisingly, Swan's GT-R performed exactly the same in performance tests as the first GT-R C&D tested. When they finally strapped it to MotorCity Speed's Mustang dyno, No. 4 put down 415 horsepower to the wheels, and with an estimated drivetrain loss of 20 percent (an average on most all-wheel-drive cars), that meant output was closer to 519 hp, rather than Nissan's claimed 480 hp.
Not content to leave well-enough alone, CARandDRIVER procured a fifth GT-R, which returned almost identical 0-60 and quarter-mile times as the fourth vehicle, along with 420 hp at the wheels on the same dyno.
You can read all the details at CARandDRIVER.com, hear Nissan's explanation for the discrepancy and see charts of both the dyno pulls and the boost levels on two of the five vehicles.