Image credit: Jeff Zurschmeide/Digital Trends
Modern cars have evolved significantly compared to their older counterparts. While we appreciate classic cars for their aesthetics and nostalgic driving experience, it’s undeniable that new cars outperform them in every aspect. Automakers have invested billions of dollars in research and development to create modern vehicles that are faster and safer than ever before, even when compensating for a driver’s skill level.
In order to gain a deeper understanding of how mechanical and electronic technology in modern cars contributes to high performance, Digital Trends embarked on a journey to the BMW Performance Center West, located at The Thermal Club raceway in Palm Springs, California.
Discovering BMW’s Technological Advancements
The BMW Performance Center West, in partnership with the Thermal facility, boasts a variety of challenging autocross-style courses, a state-of-the-art skidpad, and access to a full road course experience. From two-hour performance experiences to multi-day performance driving courses, they offer a range of hands-on classes. These classes cover not only BMW cars and SUVs, but also include options for MINI vehicles and BMW motorcycles.
To fully explore the capabilities of BMW vehicles, we participated in a two-hour experience that included driving the BMW M2, M4, M840i, X5M, and X6M. It’s important to note that these cars were in their original, unmodified state, available at any BMW dealership, and equipped with stock Continental summer tires.
After experiencing the different vehicles and understanding how size and weight influence handling, we put our skills to the test with timed runs in identical M4 sedans. This challenging course included various obstacles such as a “stop box” designed to emphasize threshold braking, as well as a range of corners and slaloms.
Unveiling the Layers of Control
BMW vehicles, like many others, feature a Dynamic Stability Control (DSC) system that utilizes sensors and control units to maximize traction and driver control. If a tire loses grip, the system can adjust engine power or apply braking force to regain traction.
In BMW vehicles, the DSC system can be partially or fully deactivated, allowing drivers to choose the level of control they desire. Even in partial deactivation, the traction control remains active to ensure stability in slippery conditions or for optimal acceleration on dry pavement. Additionally, high-performance M models offer M Dynamic Mode (MDM), which allows for increased wheel slip and later intervention from the stability and traction control systems.
The DSC system acts as the foundation of the technology that keeps the car on track when the driver makes mistakes. However, it’s not the only system at play. BMW’s technology includes several other layers of control:
- Automatic Stability Control adjusts engine torque to maintain traction, preventing wheel spin during hard acceleration.
- Dynamic Traction Control reduces stability control intervention on loose surfaces like gravel.
- Performance Control adjusts engine power and braking forces on each wheel to minimize understeer during cornering.
- Electronic Brake Force Distribution optimizes braking forces between the front and rear axles, ensuring stability during hard braking and preventing the rear end from sliding.
- Corner Brake Control regulates brake pressure during cornering to enhance stability and prevent spins.
- Dynamic Brake Control assists the driver in applying maximum brake pressure during emergency situations, reducing stopping distance.
The Assurance of Working Technology
By pushing the BMW vehicles to their limits on the test course, we were able to consistently trigger the various systems and acclimate ourselves to their effects.
With the systems fully engaged, drivers experience feedback such as a pulsing brake pedal during hard braking or a momentary “grinding” sensation as the brake controls meticulously modulate braking force to prevent the wheels from locking up. Through the steering wheel, drivers may also feel the systems intervening by applying braking action to specific wheels, aiding in smooth navigation around corners. In extreme cases, the car will significantly slow down as the various systems work together to translate the driver’s steering and throttle inputs.
Rear-Wheel Steering for Enhanced Maneuverability
Among the vehicles we tested, the M850i xDrive stood out with its rear-wheel Integral Active Steering and accompanying features. At low speeds, the rear wheels turn in the opposite direction of the front wheels, enabling a smaller turning radius for tight spaces like parking lots or driveways. At higher speeds, the rear wheels turn in the same direction as the front wheels, enhancing rapid directional changes, such as emergency lane changes.
Adapting to this feature takes some time, as it provides more steering response than expected. However, it merely adjusts the rear wheel direction in a unique manner.
The system also includes Yaw Rate Control, stabilizing the car and counteracting understeer, as well as Yaw Moment Compensation, enhancing stability during heavy braking. On the tight handling course, the M850i tended to understeer due to excessive steering inputs from the driver. The stability control system intervened to avert potential issues.
Conquering Challenges with SUVs
Handling larger SUVs on a demanding course poses significant challenges. The curb weight of an X6M is 5,185 pounds, while the X5M is even heavier at 5,260 pounds. However, BMW’s xDrive all-wheel-drive system enables these vehicles to change direction rapidly with remarkably stout performance, defying the laws of physics.
Under normal conditions, the BMW M xDrive system directs power exclusively to the rear wheels for a traditional, rear-wheel-drive experience. However, when the grip limit of the rear tires is reached, power is transferred to the front wheels to assist in cornering.
Working harmoniously with the stability and traction controls, the xDrive system optimizes engine power distribution to each wheel, maximizing traction and control. As a result, the X5M and X6M surpass the performance capabilities typically associated with traditional SUVs.
Nevertheless, it’s important to note that despite the improvements in traction and steering, maneuvering larger SUVs at high speeds on a tight handling track is still physically demanding. While the technology can enhance performance, it cannot completely transform a large SUV into a nimble M2 coupe.
Bringing It All Together
As a final exercise, we took the M4 sedans onto the Thermal south course for a few exhilarating laps. In M Dynamic Mode, the cars allowed for slightly more oversteer in corners. Equipped with the experiences gained earlier in the day, it didn’t take long to reach triple-digit speeds on the straightaways. Enthusiasts of track driving will find the BMW M4 to be an exciting companion. With M Dynamic Mode, the car permits more freedom compared to regular street-legal vehicles, while the technology remains ready to step in and prevent any unwanted incidents.
Our time at the BMW Performance Center West highlighted a clear truth: advanced technology has opened up high-performance driving to a much wider audience. By expanding the performance envelope while providing assistive measures to maintain crucial safety boundaries, BMW M models enable drivers to refine their skills with less fear of accidents. This is undoubtedly a valuable advantage.
