While Honda has broken down "Dynamic Performance" into 4 categories, "Improved Handling" was not specific enough, so they list three targeted areas of improvement in the Handling category:

• Performance at and near the limit
• Sensitivity to external forces
• Controllability

Dynamic Components

Perhaps the most obvious visible change to the '04 S2000 is the handsome new 17" wheels, wider in front and rear (by 0.5" and 1.0" respectively), wrapped in wider tires. In the front, 205/55R16s were replaced by 215/45R17 tires. In the rear, 245/40R17s bumped the incumbent 225/50R16s. Both changes are key contributors to the '04 S2000's extended cornering limits. The tires are now Bridgestone Potenza RE050s, replacing the former model's Bridgestone Potenza S-02s. The new tires feature a completly different tread pattern, intended to improve the balance in performance between dry and wet conditions.

As it turns out, the tires were the easy part. The suspension and steering tuning have been substantially revised to best take advantage of the additional grip and also to exorcise any of the perceived ills of the current setup.

In terms of spring and damper tuning, up front the spring rates have been increased by nearly 7%, while in the rear they've actually been softened by roughly 10%. Damper rates have been adjusted accordingly. The front stabilizer bar is unchanged, while the rear bar has been reduced in diameter by 1.8mm.

To enhance steering feel and accuracy, the suspension geometry was altered slightly, lowering the steering knuckles by 1.5mm. The EPS (Electrical Power Steering) system features an optimized steer response gain, while the software was updated to improve steering linearity and agility. The steering gear ratio was also changed to match the new suspension and tire characteristics. Increased rigidity of the steering gearbox supporting mounts results in improved steering precision as well.

One of the "features" of the outgoing S2000's rear suspension was its tendency to exhibit bump steer at the limits. Honda's engineers have attacked this issue from several angles. The first was to reduce the rear bump toe-in. At a 50mm bump deflection, toe-in has been reduced from -0.19 degrees to -0.05 degrees. Secondly, the rear roll center was lowered from 101mm to 92mm. And finally, the initial toe-in setting has been slightly reduced, further improving the linearity in response.

These enhancements result directly in improved roadholding under full suspension compression or during severe body roll situations. Obviously, this greatly improves dynamic stability.

Static Components

A suspension designer's task is greatly simplified if he can count on excellent chassis stiffness. While in a practical sense, a perfectly rigid chassis is impossible, it's always possible to design ever stiffer chassis, with the tradeoff usually involving packaging, cost, and weight concerns. Honda's engineers have tweaked the S2000's equation a bit, resulting in an improvement in overall body rigidity of approximately 10%. This is no mean feat, given the existing S2000's world-class stiffness. This was achieved through the use of additional reinforcements or bracing at various locations in the chassis, including a new cross brace at the very front of the frame (positioned horizontally, in front of the radiator), reinforcements at key crossmember joints, additional fixing points to existing braces, and reinforcements to the rear wheel arch bulkhead. Additionally, the front suspension upper arm brackets were strengthened, further benefitting handling.

Results

Handling related improvements are comprehensive. Honda claims improvements in overall stability, steering accuracy/effort/feel, bump steer characteristics, wet performance/hydroplaning, high-speed stability, smooth ride comfort, choppy ride comfort, and at the limit controllability.