Gran Turismo 4, the world's most ambitious racing simulator is definitely more than a game, says CAR correspondent Hannes Oosthuizen. Be prepared for sore thumbs and strained eyes once it arrives...

by Hannes Oosthuizen

I'm driving a full DTM racing version of the Audi TT around the Nürburgring Nordschleife, one of the most daunting tracks in the world. Every ferocious gearshift momentarily blurs my vision. The acceleration is shattering, pushing my upper body into the seat and giving my stomach muscles a serious workout. My hands are sweating because the camber changes from corner to corner, combined with the many little bumps, threaten to send me shooting off the track at any second. I'm struggling to focus. Things are happening mighty fast.

Then, at around 250 km/h, the steering goes all lifeless as I crest a long uphill section. The TT is launched into the air, instantly turning me into a helpless passenger. As the nose dips down, the next corner is looming large. Bouncing forward violently in my seat as car meets up with terra firma, I try to brake but it is too late. Oh dear. The TT is in a rapid slide now. Through the tyre smoke I can make out the armco. This is going to hurt. Then I hit the pause button...

The $30 000 Subaru-built simulator levels off and lowers. I get out, my legs are shaking a fair bit. And I'm sweating. That felt so real. Welcome to the adrenaline pumping world of Gran Turismo. This is no longer a game, but a full-on racing simulator.

But seriously now, just how real can a "computer game" actually be? I ask the game's creator, Kazunori Yamauchi to put a percentage figure on that question. With an absolute poker face he says, "80 per cent." That's quite optimistic, I think, but then again, after playing for a solid hour I do have blisters on my palms and a pounding concentration-induced headache. To reach 100 per cent, Yamauchi says, he'll need a processor that is a thousand times more powerful than the one in PlayStation 2, and another ten years of development. He says these things in a matter-of-fact way - there is no "perhaps", or "if possible".

Kazunori's quest for perfection has led to the delay of Gran Turismo 4 several times, but by the time of my visit to Tokyo in October, the details have been frozen. However, his 70-strong team at Polyphony studios was still working flat-out to put the finishing touches on the game in time for a late-December release. Some of them sleep at the office, either in a "capsule" room with closely stacked bunk beds, or in sleeping bags kept under their desks. Shower, relaxation, training and kitchen facilities mean they don't really have to go home. Ever.

The detail work that happens at Polyphony is astonishing. In GT3 it took a single designer a month to model a car. According to Yamauchi, there is now 40 times more work to do on every model. Each car is photographed and video recorded from every possible angle, measured, and then the entire rev range is sound recorded. But the most important work is to get the cars technically accurate.

The secret of Grand Turismo's success (around 35 million copies have been sold since 1997) is its "physics engine". The aim with this engine is to recreate authentic handling, performance and even engine sounds on every car in the game. Quite a tricky task, especially if you keep in mind that no less than 650 cars are included in GT4!

Yamauchi says the physics engine is basically a comprehensive set of parameters that gets altered for every car. For example, the power and torque curves, tyres, gear ratios, drivetrain and suspension layout and even the length of a driveshaft are fed into the physics engine. But these "virtual" cars are not the figment of a computer processor's calculations. Yamauchi has driven many of the featured cars in anger around the Motegi racetrack. He has raced around the Nürburgring in Skyline GT-R racing cars and posted very good times. And he is a member of the Japanese Car of the Year judging team. He owns a "slightly tuned" Nissan 350Z, Honda S2000, Porsche 911 GT3, Mercedes-Benz SL55 AMG and a Mitsubishi Lancer Evolution. Yamauchi knows cars. That is very clear.

Initially the world's car manufacturers were not very keen to have their products race against rivals in a computer game, for obvious reasons... they miGT4 also features a Gran Turismo Resort. This includes "My home", which acts as a garage for up to a thousand cars. Some of the world's most famous tuning sho