In Depth: Lexus RC 350 F Sport – what’s in it?

The premium sports coupe segment is about to get a lot hotter. Japanese luxury player Lexus has joined the party with the all-new 2015 Lexus RC 350, which has just been launched in North America.

The new image-building coupe melds audacious design and high performance like no Lexus before. Engineered as a stand-alone model, rather than as a two-door derivative of a sedan, the RC has been tasked to deliver all the performance, individuality, and fun-factor that the brand needs to shake off its boring perception. Lexus expects the RC to attract the next generation of luxury buyers and those new to the brand.

While the RC 350 swaggers with a striking exterior, it features efficiency under the bonnet.  A 234kW/380Nm 3.5-liter V6 teamed to an eight-speed Sports Program Direct Shift (SPDS) transmission driving the rear wheels.

From launch, Lexus will offer the new RC 350 in both rear-wheel drive and with all-weather drive (North America only), the latter using a six-speed automatic transmission, and an F SPORT version. Distinguished by exclusive exterior design and interior features, the F SPORT will also raise the performance ante with standard Adaptive Variable Suspension (AVS) system and the available Lexus Dynamic Handling system, which includes rear-wheel steering.

The Lexus RC is expected to hit showrooms in Australia in early 2015.

Unique Platform

The Lexus RC’s chassis is unique, although it does draw from the architecture of other Lexus vehicles. The front end is based on the much-touted Lexus GS, which set new standards for stiffness and chassis response in a mid-sized sedan.

The rear of the RC platform is based on the new-generation IS sport sedan, a car that has already proven its performance and handling mettle in a hotly contested segment.  In the center, where the structure needed to maintain rigidity with two large door openings, Lexus borrowed from the IS convertible structure.

None of those three portions was directly taken from the other cars. Rather, each contributed more than the sum of its parts to the overall chassis package. Lexus fine-tuned the resulting platform to provide the specific high-performance character sought for its new coupe.

High Rigidity Body

To create the best-handling regular production Lexus yet, Lexus started with the handling stars of its current line, adapting portions of their platforms to create a rigid foundation for the RC. The front suspension area is based on GS, with increased apron panel thickness. The center floor section, based on the Lexus IS C, has an enlarged rocker cross section – nearly double that of IS sedan — to help improve control. The rear floor is based on the new-generation IS sport sedan, with added center-floor reinforcements.

As it did with the IS, Lexus applied new manufacturing techniques to yield a rigid body structure. Laser screw welding, additional spot welding and special body adhesives all do their part to help give the RC a strong body. High-rigidity structural adhesive is used to help secure the windshield and backlight.

Under-floor braces added to the radiator support and number-two cross member, along with a front A-brace, tunnel brace and trapezoidal rear brace, all help contribute to rigidity.

Powertrain: An atmospheric V6

In an era where turbochargers are replacing displacement, Lexus chose a naturally aspirated V6 for its instantaneous response and unique sound. The aim is to deliver a distinct but refined growl under acceleration and a pleasingly present but quiet demeanor when cruising. An intake sound generator further enhances sonic appeal under acceleration.

The 3.5-liter 2GR-FSE V6 features aluminum block and heads to keep weight in check. Key technologies that get credit for the broad torque curve and quick response include intelligent dual variable valve timing (VVT-i) and the Lexus D-4S system of direct and port fuel injection. With one injector installed in the combustion chamber and a second mounted in the intake port, D-4S combines the strengths of both for maximum efficiency and low emissions.

Dance Partner: Eight-Speed SPDS Transmission

Eight is enough. That’s certainly true of transmissions for high-performance cars. But what’s the best way to control the gears for the ideal performance experience?

The 2015 Lexus RC 350 answers with the new eight-speed Sports Program Direct Shift (SPDS) transmission. This transmission debuted in the esteemed IS F high-performance sedan. The SPDS transmission combines the best of both worlds: torque converter smoothness with shifting speed of a dual-clutch unit when shifting manually. A long-travel damper for the lock-up torque converter boosts fuel economy and ensures smooth, quiet lock-up.

The SPDS transmission has three driver-selectable modes – NORMAL, SPORT and MANUAL (M), which have full torque-converter lock-up from second to eighth gears for “clutchless” manual shifting. Downshifts are made in just 0.10-second in M mode, with the transmission’s throttle blipping control matching the engine speed to the gear. The transmission’s shift control has been further developed to respond precisely to slight changes in accelerator-pedal operation for an even more dynamic and inspiring driving feel.

The eight ratios have been chosen to balance the needs of performance driving and fuel efficiency. Compared to the Lexus six-speed automatic transmission, first gear is 8.5 percent shorter and top gear is 2.9 percent taller.

SPORT mode introduces G-sensor AI-Shift control, which uses information from the G-sensor on driving status to provide the optimal gear ratio for sporty driving. In SPORT mode, the transmission will automatically downshift during hard braking for a corner, hold a lower gear through the corner for greater control, and then give the driver a greater power response on corner exit by selecting a suitable low gear.

NORMAL mode provides fuel economy and seamless acceleration traditionally associated with Lexus electronically controlled transmissions. It uses all eight gears for optimum fuel economy, while coordinating control with the throttle to provide smooth acceleration and minimal feeling of gear changes.

Chassis Dyamics

The RC likewise draws its suspension design, though not the individual parts, from the GS architecture. The front suspension is double wishbone, and the rear suspension is multi-link with a toe control arm. Monotube dampers offer ideal damping and control for a high-performance car.

Because the RC is much stiffer than the vehicles that have contributed platform technology, Lexus was able to employ much higher damping forces and use larger diameter stabilizer bars front and rear, all without adversely affecting ride comfort.

Most of the suspension components are new. At the front, the RC gets a new suspension upper support, coil spring, damper, stabilizer bar, stabilizer bar bushing and lower number two bushing.  The rear coil springs, dampers, stabilizer bar, and stabilizer bushings all are new for the RC.

RC 350 F SPORT takes handling acumen to a higher level with Adaptive Variable Suspension (AVS) system and the Lexus Dynamic Handling system with Dynamic Rear Wheel Steering.

Aerodynamic Grip

The Lexus RC’s aerodynamic performance leverages the flow of air over and under the car to help optimize controllability, especially when traveling at high speeds.

Aero-stabilizing fins and a flat under-body design are among the myriad details that ensure the RC slips through the air as efficiently as possible. The aero fins are strategically placed in key areas of the underbody, and there is also an aero-stabilizing guide behind the front bumper to suppress vortex formation and increase radiator efficiency. Stabilizing fins are also fitted to the tip of the doorframe molding and the rear lights.

Ducts in the front bumper enhance aerodynamic and brake-cooling performance. Even the shark-fin style radio antenna plays a role in aerodynamic. The sharp cutoff at the trunk edge helps to smooth airflow from the roof. Rear under-floor aero devices to help create negative lift, and the angle of the rear under cover has been raised, for optimum aerodynamic effect.

Front fender liners have an aero-groove shape to help direct airflow along the tires, in the same direction as the wheel rotation. The rear fender liners have a bead to direct tire-generated airflow to the outside of the vehicle. Door parting line gaps were reduced to 3.8 mm to both enhance appearance and reduce wind noise. Finally, the roof panel is brazed directly to the side members, eliminating the need for a roof drip molding.

Electric Steering

Exclusively for RC 350 F SPORT, the electric power steering features Variable Gear Ratio Steering (VGRS) which automatically changes the steering gear ratio in response to vehicle speed and driving conditions. To reduce the steering angle when turning the steering wheel at extremely low speeds or when performing a U-turn, VGRS decreases the number of turns of lock to lock.

In urban areas, on mountain roads, and other situations when the steering wheel is frequently operated at low to mid speeds, an optimum ratio is selected to provide light, easy-to-handle vehicle responsiveness.

F SPORT: Lexus Dynamic Handling And Rear-Wheel Steer

The RC 350 F SPORT is equipped with Adaptive Variable Suspension (AVS) and the Lexus Dynamic Handling (LDH) with rear-wheel steering technologies.

The LDH system, available for F SPORT RWD only, is designed to help enhance maneuverability and reduce steering effort at low speed; help increase steering responsiveness and intuitive steering feel at medium speeds; and help enhance control at high speeds. It does so by integrating electric power-assisted steering (EPS) to control steering torque, variable gear-ratio steering (VGRS) to control front-wheel steering angle and Dynamic Rear-wheel Steering system (DRS) to provide the benefits of four-wheel steering while maintaining the feeling of a conventional two-wheel steer vehicle.

LDH is designed to provide the ideal wheel front and rear wheel steering angles to help with optimum response and safety at most vehicle speeds and in most driving conditions. At speeds up to approximately 50 mph, the system slightly turns the rear wheels the opposite direction as the front wheels to help tighten the turning radius and enhance cornering performance. Above approximately 50 mph, the front and rear wheels turn in the same direction, for enhanced high-speed control and a more natural-feeling vehicle posture through high-speed corners.

DRS is integrated with the RC 350 F SPORT Drive Mode Select SPORT S+ mode, which changes the DRS characteristics to enrich steering response and the performance-driving feeling. In addition, the system interacts with Vehicle Dynamics Integrated Management (VDIM) and the Pre-Collision System (PCS) to help avoid or rectify vehicle instability in an emergency situation by optimizing front and rear wheel angles.

F SPORT: Adaptive Variable Suspension

The Adaptive Variable Suspension (AVS) system on the RC 350 F SPORT monitors steering input and road conditions and adjusts the dampers to suit, using inputs on vehicle posture including lean, dive and squat. The system continually optimizes roll attitude and rebound control to help achieve a flatter ride and more natural vehicle posture. When the driver selects the SPORT S+ setting in Drive Mode Select, AVS switches to maximize the damping force for ultimate handling response.

AVS works in three ways:

• When driving on a rough road surface, AVS switches to a lower damping force (oil moves through the dampers quickly) to help absorb vibrations for a smoother ride.
• When the RC pitches forward or back (during heavy braking or hard acceleration), damping force is increased (less oil is allowed to move through the damper) for ideal vehicle composure. These motions are detected from the brake/accelerator pedal, not just from vehicle angle sensors, to ensure early AVS reaction.
• During cornering, damping force is increased to help ensure handling and reduced body roll through the corner.

Lexus AVS can also interact with the VDIM system and PCS to optimize damper rates in response to potentially hazardous situations. For example, the AVS applies increased front damper force as an anti-dive measure during emergency braking.

Exterior Design

The RC has been infused with deeply contoured lines, integrating the widest and lowest application yet of the Lexus spindle grille. It is 1.2-inches wider, 1.4-inches lower and 2.8-inches shorter in wheelbase than the new IS sedan, providing a road stance that emphasizes the sporting characteristic of a premium two-door coupe.

The unique headlamp design adopts the symbolic Lexus L-shaped motif front and rear. There are two choices of aluminum wheels – a deeply sculpted 10-spoke 19-inch and a muscular five-spoke 18-inch.

A new red exterior paint color is made brighter and shows more contrast thanks to a new painting process.

Interior Design

The RC interior makes maximum use of contrasting colors, materials and lighting, in a similar design based on the IS interior.

A purpose-built Lexus-first lighting package aims at providing a great sense of occasion, with illumination that reflects upwards, rather than downwards, to envelop the cabin. High contrast interior colours emphasise design lines and accentuate the cabin. Genuine shimamoku wood highlights – the result of an intense, layered wood production technique refined by Lexus – are used to emphasize the surrounding trim.

The driver’s cockpit is divided into operational and display zones. The upper zone houses the instrument panel and a seven-inch navigation screen while a layered center console integrates a new generation Lexus Remote Touch Interface.

The seats utilise an integrated foaming construction method, much like the molding of racing seats, to ensure optimum occupant comfort and support which is important in a sport coupe.

Lexus RC Coupe gallery