BWI Group Launches Automated Semi Active Roll Control System
Automated roll control system can be connected and disconnected on demand while driving at speed
SARC removes the compromise between handling and comfort while also improving off-road capabilities
Its unique hydraulic architecture enables mode transitions at any suspension travel and even under load
BWI Group has developed an automated active roll control system. The latest update to the company’s SARC (Semi Active Roll Control) product features a new ‘automatic mode’ that enables a vehicle’s anti-roll bar to disconnect and reconnect seamlessly on demand while driving at speed.
The update addresses an increasing challenge in modern chassis engineering as vehicle mass continues to grow. With SUVs accounting for more than half of new car registrations in Europe in 2024, and BEVs typically around 30% heavier than equivalent ICE models, engineers are increasingly forced to compromise between roll stiffness for handling and compliance for comfort. Heavier vehicles necessitate stiffer stabiliser bars, which extenuates the issue.
SARC’s automatic mode aims to remove this compromise. By disconnecting the bar during normal driving, the system allows the vehicle to adopt a softer, more compliant baseline, only engaging the stabiliser bar when required. The control unit uses vehicle data, such as steering angle, speed, lateral acceleration and yaw rate, to determine when the bar needs to reconnect. During high-speed cornering, for example, it reconnects in less than 200 milliseconds and is imperceptible to the driver.
“Chassis engineers are continually trying to improve road handling and comfort, but the two goals are often incompatible,” said Bruno Perree, Engineering Manager at BWI Group. “The latest update to SARC removes that compromise, allowing engineers to optimise the roll bar purely for handling as it will be disconnected the majority of the time. This not only improves comfort but also adds significant off-road capability, which can be a key competitive differentiator in a crowded SUV market.”
At the core of the system is a compact rotary actuator paired with a fully self-contained hydraulic mechanism. The hydraulic architecture enables the bar to be connected or disconnected even when the wheels are unevenly articulated, which is something mechanical solutions typically cannot achieve. Automatic self-centring using the company’s EZ-Latch™ technology ensures consistent engagement throughout the suspension travel.
SARC is in production on several global platforms, most recently the GWM Tank series, where it is used to balance on-road composure with off-road traction. The addition of SARC’s automatic mode is expected to broaden its application to a wider range of SUVs and BEVs, where managing mass and maintaining ride quality have become central engineering priorities.