yikesJapanese GT-Rs are speed-limited for the street: As has been widely reported, unless it's driven on a preapproved racetrack, a stock Japanese-spec GT-R is limited to 180 kph (111.8 mph) with the factory settings. GPS sensors in the navigation system track vehicle position and communicate with the ECU. Try to exceed 180 kph, and a warning light will appear on the instrument panel. Only shutting the car off and restarting it will get the light to disappear.
But can be run all-out at the track: Running a GT-R at the track requires scrolling through menus in the on-board computer and selecting the racetrack option that bypasses the speed limiter. Only then can the car be run to its full potential.
Though it'll cost you: Once the track day is over, owners who have run their GT-Rs over the speed limit are required to take them to a preapproved Nissan High Performance Center for a safety check. Failure to perform this $1000 service will void the factory warranty.
As for the wheel and tire rumor: That the factory wheels cannot be removed without sending an error code to the ECU, MINE'S has proven this myth wrong. It's been able to take off wheels, rotate them, and even change to higher-performance, non-run-flat tires. It did have to take the wheels to the Nissan dealership to get the job done at great expense; MINE'S ended up paying about $230 per wheel in labor.
Putting aftermarket rims on a GT-R is a different story: Because of a sensor located near the valve stem in each wheel, it isn't possible for the car to run on aftermarket rims without throwing an error code. All blinged-out GT-Rs at Auto Salon got there on stockers and only then were the shoes changed.
Some mild mods are possible: MINE'S has modified the exhaust system and a replacement air-filter element, both of which have reportedly made substantial extra power. It's also upgraded the brake rotors and switched to GT-R's suspension system to a coil-over system with no ECU problems.
But not all: MINE'S has tried replacing the factory air box and intake system with a high-flow cone-style system, but found its car will not run right. Raising the boost pressure on the twin turbos, a common way to increase power, also triggered errors in the extremely sensitive ECU.