Hoping to keep modified cars off the streets, the Japanese government worked with Nissan making it clear that any modifications to the GT-R would void the car’s warranty. Meaning if you touch anything under the hood, drop its height or remove the speed limiter (which is limited to 112 mph for JDM-spec models), your warranty will be automatically voided. However, that’s not stopping tuners to get as much as power and performance as they can out of the GT-R. Supposedly Power House Amuse Phantom GT-R is the fastest and most powerful 2008 GT-R in the world.According to AutoWeek, Hideki Tanabe, president of Power House Amuse, and his team of engineers have extracted a total of 620-hp with a maximum torque of 571 lb-ft from the 3.8L V6 engine. Amuse also got rid of the...