SunLine Racing Nissan GTR Tukuba Time Attack

Date: April 9, 2009
Weather: Fine weather conditions
Temperature: 24 C (75.2 F)

SunLine Racing’s best time was 1.00.131

Regrettably the SunLine Racing GTR did not break the 1 min barrier. However, considering the high air temperature during this Tukuba Time Attack, we are confident when lower temperture’s after this summer season ends, breaking into the low 59 seconds time will be a sure thing.

SunLine Racing R35GTR Spec

In preparation for the Tukuba & Fuji Time Attack, SunLine Racing repeated their track runs at Okayama International Raceway to perfect the settings of its newly released TCD (Traction Control Differential). Mr. Sato, President of SunLine stated, "Our TCD has improved our lapping time close to 2 second at Okayama. We are hoping for a marked improvement at both Tukuba and Fuji.”

Modification of our engine included the Intake & Exhaust tuning. We increased the maximum boost to 1.3kg/cm2, and our CPU was reprogrammed with Access Port. The footwork was tuned with the Trace suspension with a 18kg/mm front spring and with a 16kg/mm rear spring. Our tires are the 285/35 Dunlop SP Sport 600DSST for both front and rear.

Driver’s Comment: Professional driver - Yasushi Kikuchi

The reason for using the 285 wide tires in front was to gain more road contact area. Although a 255 tires give you a quicker initial response to your steering input, the 285 provides much better control during cornering. The wider front tires ease the feeling of the “heavy GTR”.

The SunLine TCD will greatly improve the forward momentum even when the rear starts sliding. The TCD will make “counter” steering easier by eliminating the need for constant adjusting. The reliance on the electronic control system seems to be reduced and the GTR becomes more like a “driver’s” car. With TCD, I felt as if the car became lighter.

If it were with a stock LSD, once the rear begins sliding, that would have led to a four wheel slide with a constant need to adjust the steering. TCD provided a faster and more stable driving control on the race track.

There are a few points I would like to see improvement on, the boost shoots up to 1.3kg/cm2 with the accelerator wide open, but it goes back to 1.0kg/cm2 pretty quickly. This must be caused by the stock actuator. The Nissan ATTESA system was not optimum when driving on the race track. The torque seemed to be distributed more toward the rear. I would like to see little more pull from the front end.

Even with those minor points, anyone can feel the improvement that the SunLine TCD produces. With the TCD, the vehicle’s behavior from going into a corner to the exit becomes very straightforward and controllable. As your driving skill improves, the TCD becomes more valuable and advantageous on your Time Attack results.