A Special Lesson

In late February last year, as the harsh winter cold in Tokyo subsided and the weather remained completely snow-free, the Gunma Cycle Sports Center at the foot of Mt. Akagi was buried in heavy snow. In this area, where snow depth reached over a meter in places, the final snow driving training session of the winter season took place. Dr. Ryozan Saito, who introduced us to this program, was primarily there to test drive the Subaru Impreza built by Arai Motorsport. Instructing him on his driving was Toshihiro Arai, who won the Production Car World Rally Championship (PCWRC, now PWRC) in 2005, becoming the first Japanese driver to achieve the feat of becoming an international four-wheel motorsports champion.


Every year, Mr. Arai hosts an ice driving event at Yachiho Lake in Minamisaku, Nagano Prefecture, about seven times from mid-January to mid-February, organized by Arai Motorsport. The aim is to improve driving techniques through driving on extremely low-mu surfaces. The program Dr. Saito participated in this time is an advanced version, offering the chance to learn Mr. Arai's skills in a near one-on-one setting. Dr. Saito, who stayed overnight to receive the lessons, showed remarkable improvement with every lap, which was clearly visible.

Master the 'Sudden,' and the 'Gentle' Becomes Easy

The general theory for snow driving is to avoid any 'sudden' inputs. However, according to Mr. Arai, in rallying, sudden inputs are sometimes necessary to instantaneously change the car's behavior. While difficult for most people, he explains that mastering this makes it easier to drive slowly on snow. Indeed, acquiring the skill to navigate the course while keenly aware of the car's dynamics, as in snow rallying, would surely dispel any anxiety about low-speed driving in urban areas. On a snow course, even if you go off into the snow, serious injury is rare. Practicing on a closed course without oncoming traffic, he says, dramatically improves low-mu driving technique.

Gaining Experience is the Fastest Way

In fact, Dr. Saito's car, which had been spinning into the snow walls on the same corner for the first few laps, began to drive more smoothly with each subsequent lap. Mr. Arai attributes this to the timing of returning the steering. He explains that after turning the steering towards the corner and the nose enters the turn, the steering must be returned immediately; failure to do so results in hitting the wall. Even on paved roads, he emphasizes, the timing of returning the steering is more crucial than initiating the turn. He insists that if the timing is perfect, one can become a skilled driver on any road surface.
However, what differs on snow or dirt compared to pavement is the slip angle. Slip angle is the difference between the direction the car intends to travel and the angle of the tires; on pavement, because the tires grip with their surface, exceeding a certain slip angle results in understeer. On snow, however, one cannot rely solely on surface grip. Therefore, Mr. Arai advocates for increasing the slip angle. In other words, the concept is to use the resistance of the tire sidewalls to turn. By turning the steering wheel fully, the front gains grip, and the rear begins to slide. Repeating this process, quickly transitioning to the next action at the right moment, enables precise snow driving. However, this is something that can only be truly understood through actual driving experience. Arai Motorsport will be holding ice driving events in 2012 as well, so why not start there?

Arai Motorsport
http://www.araimotorsport.com/