GET YOUR WHEELS TURNING

Generating twice the factory horsepower output would certainly overtax the GR6 dual clutch transmission (DCT). Putting its full engineering capabilities to work, HKS produced a prototype GR6 clutch and gear set upgrade. The upgraded clutch pack features a reinforced basket in addition to upgraded discs and plates for greater torque capacity. The gear set includes wider gears for increased horsepower and torque capacity, along with a rigid steel sandwich plate to retain the main and countershafts instead of reusing the factory aluminum plate. For good measure, HKS also added a DCT cooler and a differential cooler.

Suzuki explained, “The DCT is a necessity for aggressive driving. The ECU fuel cut-off activates when the DCT fluid temperature reaches 140°- 145°C (284°-293°F). Also, when the AWD clutch temperature rises, the drive mode is switched to 2WD even if the fluid temps are below 140°C. A warning message will appear when the oil temperature of the drivetrain parts reach an abnormally high level. The warning message will also appear if there is an improper revolution difference between the front and rear wheels.” Further tuning of the driveline comes in the way of HKS electronic wizardry, an Active Torque Split Computer (ATSC). Designed as a piggyback supplement to the factory systems, the ATSC offers four preprogrammed levels of torque split that can be changed at the push of a button. According to HKS, adjustment of torque split helps to neutralize the handling while optimizing power delivery, especially under hard driving conditions.

WORTH THE WAIT

Development of the GT1000 kit took approximately two years, involving a combination of bench tests, street driving evaluation and track testing at Fuji Speedway. Suzuki concludes, “We spent a lot of time in research and development, especially when it came to sizing the turbochargers properly. Fine tuning the GT1000 kit to work efficiently and effectively on the street and the track was our top priority. The VR38 is a great engine, with the greatest displacement of any Japanese tuning platform and it is capable of incredible horsepower and torque output. Final development of the GR6 transmission components should be complete by June 2013. Once combined with the GT1000 kit, the GT-R should answer the call of high performance enthusiasts around the world.” That is, until the requests come in for a GT2000 kit.