In 2004, Honda made several significant changes to its flagship sports car, the 2004 S2000. Most important of these changes was the engine. Honda enlarged the 4-cylinder from 2.0L to 2.2L in order to address complaints that the engine lacked torque and was too high-strung. This new, larger power plant resulted in more peak torque, about 10% more power throughout the rpm range, a lower red line, torque peak, and horsepower peak. Other drivetrain-related changes for 2004 included a transmission with wider-spaced ratios and carbon-fiber synchros. The 2004 S2000 also got a limited-slip differential for better traction.
Honda also revised the suspension of the 2004 S2000. The new suspension had revised spring rates and dampers, front and rear. It also had a modified geometry which introduced mild toe-in under cornering loads. Honda did this to address complaints of the S2000 being too willing to swap ends if the rear end broke loose. The suspension changes got rid of this over steer and made the S2000 much more neutral and forgiving. Other performance tweaks in 2004 included new, larger 17" wheels and high-performance Bridgestone RE-050 tires. To compliment the additional traction, the S2000 got new brake pads which provided shorter stopping distances and better feel.
The 2004 S2000 also recieved some cosmetic upgrades in 2004. Inside, it got new seats with integrated headrest-mounted speakers and XM radio. Outside, it got new, more aggressive front and rear bumpers, and new headlights. Out back, the S2000 was upgraded with new LED taillights and oval exhaust tips.
