NAIAS Highlights: Production
A sporty look for Lexus
To ensure low NVH levels, with the roof up or down, wind-wrap tests were used to style Lexus' 2002 SC 430 hardtop convertible. By designing the car as a convertible from the start, engineers optimized its structure to provide strength whether the aluminum-alloy hardtop is up or down. The retractable hardtop, operated by a button, transforms the SC 430 from a 2+2 coupe into a convertible in less than 25 s.
The rear-wheel-drive, 4.3-L, V8 convertible is powered by a 224-kW (300-hp), all-aluminum, double overhead cam engine with variable valve timing with intelligence (VVT-i) and 440 N•m (325 lb•ft) at 3400 rpm. Linear acceleration is achieved through a newly developed electronic throttle control system, the Intuitive Powertrain Control. The V8, which meets ULEV emissions standards, is coupled with a five-speed automatic transmission for acceleration from 0-97 km/h (0-60 mph) in 5.9 s. In addition, the convertible's front and rear double wishbone independent suspension minimizes vibrations and contributes to a smooth ride. A weight distribution of 53/47 provides good balance for further performance enhancements.
The SC 430's braking system features four-sensor, four-channel antilock brakes (ABS), electronic brake-force distribution (EBD), traction control, vehicle skid control, and brake assist. EBD monitors all four wheels during braking and varies brake pressure according to load on each wheel. Brake assist is designed to determine if the driver is attempting emergency braking; if the driver has not stepped hard enough on the brake pedal to engage ABS, it supplements the applied braking power.
The convertible also has a new tire-pressure warning system that uses coded sensors to monitor the tire air pressure directly and transmit this information to a receiver via radio frequency communication. The receiver calculates the information and, if a drop in pressure occurs, a buzzer sounds. Optional run-flat tires are another safety feature of the SC 430. With the tires, the vehicle can be driven up to 161 km (100 mi) at speeds up to 89 km/h (55 mph) with a punctured tire. In addition, there is no need for a spare tire, which frees up trunk space. Other safety features include reinforced structural components, such as the rocker panel and the rear deck lid, for collision protection; standard dual front and front-seat mounted side-impact airbags; daytime running lights; and HID headlights.
Features within the SC 430 include an advanced climate control system that adjusts airflow and temperature automatically, differentiating between top-up and top-down driving needs. The climate control system will take into account the exterior temperature to help ensure occupant comfort. When driving in cooler weather with the top down, the system will direct warm air to the foot and lap areas and, on hot days, will circulate cool air to the same target locations. The convertible also includes a new sound system with nine strategically placed speakers. The equalization of the system automatically adjusts when the roof is lowered and returns to its original levels when the top is raised. Essential functions of the sound system can be operated via controls on the steering wheel.
- Ryan Gehm
