Forza Motorsport 3

Imagine you're driving an EVO X that makes 747 hp and has the mods to hang with GT1 race cars when you run against them at Le Mans, Nürburgring or Laguna Seca. Thanks to Forza Motorsport 3,an Xbox 360 driving simulator, you can live this scenario in real time. The latest version of the game features new high-def tracks and more than 400 cars. Extensive research delivers unequalled detail to interior and other design cues, even down to the exhaust note of the car in question. The resolution is sure to be mind-blowingly vivid as each car has been created with more than 10 times the amount of polygons used in Forza Motorsport 2.

Tires: The Deal Breakers
Forza 3 is about more than good looks, it feels like no other driving game. In the eye of the storm we find an advanced physics model that goes to great lengths to simulate the driving characteristics of each individual car. The system is so leading edge it can monitor tire flex, heat buildup and weight transfer as well as the grip quotient of the track surface to provide super-realistic handling. "Tires are the absolute heart of any driving simulator," says Forza game director Dan Greenawalt. "You have to get the tires right. If the tires aren't right, the simulation is worth nothing. Suspension is extremely easy to do, frankly. It's a three-point architecture or a four-point architecture-it's just straight up math, spring rates, dampening and unsprung weight.

"Michelin, Toyo, Falken and Bridgestone, these companies learn new things about tires each year and it's important to us to keep our tire simulation on the leading edge, so we work closely with these companies to get detailed data from their latest and greatest testing, which has kept FM3's tire simulation on the cutting edge.

"At any point you can use the D-pad button to call up the telemetry and see how the tires are actually being used," Greenawalt adds. "You can see friction and when you're beyond peak grip. You can see when the car is understeering because the front tires go red before the rear. You can also monitor and tune tire pressure and the suspension. This is all real time as the car is on the track. The surface of the tire on the outside and inside edges and the condition inside the tires are measured independently for heat and displayed. It's a fully cyclical, positive-reinforcement system. So if I did a burnout, the outside of the tires will heat up almost instantaneously, but the inner gas will heat up much more slowly. And it would cool down quickly. But if I did a long burnout, even the gas inside will get hot and once it's heated up it will take forever to cool off. We have a heat detection system in there that is very realistic.

"Tire flex is a huge innovation in FM3," Greenawalt continues. "In some cars you can see the tires roll over. The amount of flexion and tire rollover is dictated by how much air you put in the tires, how high the sidewall is, tire compound and sidewall stiffness. In a high-sidewall, small-rim, weak-compound situation you're going to feel the car float over its tires, roll the sidewall. And the back end just walks like a dog and follows the front through a corner. High-performance tires provide better lateral control, and better performance.

"Tires have variables that change continuously up to and including the track itself. The tracks on FM3 feature varying friction coefficients. Also, some of the tracks are bumpy which lifts the tires and lowers grip. We have tried to think of all the angles."

Deep Tuning Garage:
Performance Mods
When it comes to performance, each ride is ranked so players can match up against equally capable cars. A car with a rating of F100 is far slower than an A100, and S and R are race car categories. The number denotes the car's standing within the category.