Electronic Limited Slip Differentials
Finally, we're ready to get right to the heart of the matter: What exactly is an eLSD? It's not the latest trippy, feel-good club drug, and it's not related to any paranormal phenomenon or sports channel we've heard of. No, it all comes down to performing the same tasks as normal limited slip differentials, often with pressurized hydraulic clutches, only with sophisticated electronic fine-tuning.
An eLSD system makes sure each wheel is receiving sufficient torque by use of an electronic control unit, be it microcomputers or the vehicle's main computer. The system electronically monitors input from various wheel sensors and, in the event of slippage, transfers extra torque to the wheel or wheels with the most traction. Some models even allow drivers to choose particular settings for the system,. For instance, Mitsubishi's Active Center Differential allows drivers to choose specific presets for driving on the road, gravel and snow. An eLSD also allows for better handling during high-speed curves and lane changes, performing all the tasks of standard differentials, only with computerized speed and precision.
An eLSD system can also help with vehicle yaw. If viewed from above, yaw is the vehicle's rotation around its central point during a turn or lane change. In all-wheel drive vehicles, rear eLSD systems help keep the rear of the vehicle closely attuned to the direction of the front wheels, dampening the yaw. If the yaw is severe enough, it can send the vehicle into a spin. For this reason, eLSDs are sometimes referred to as active yaw controls.
So there you have it: eLSD systems are a computerized update of limited slip differentials, providing some of the snazziest vehicles on the market with truly superior handling. Currently, eLSD systems are available in Saab cross wheel drive vehicles, as well as assorted vehicle models from Mitsubishi, General Motors and Jeep. Often, the feature figures into an overall chassis control or electronic stability system.
Explore the links below to learn even more about automobile technology and vehicle handling.
Related HowStuffWorks Articles
More Great Links
- "Active Yaw Control." Mitsubishi Motors. 2008. (Nov. 13, 2008)http://www.mitsubishi-cars.co.uk/features/ayc.asp
- "Differentials and Limited Slip Differentials." Driving Fast. (Nov. 13, 2008)http://www.drivingfast.net/technology/Differentials.htm
- Nice, Karim. "How Differentials Work." HowStuffWorks.com. Aug. 2, 2000. (Nov. 13, 2008)https://auto.howstuffworks.com/differential.htm
- Rivoli, Cascine Vica. "Oerlikon Graziano Drive Systems." April 2007.
- "Saab XWD Cross Wheel Drive." Zer Customs. Nov. 20, 2007. (Nov. 13, 2008)http://www.zercustoms.com/news/Saab-XWD-Cross-Wheel-Drive.html
- "Turbo X World Premiere at Frankfurt Auto Show: Saab Unleashes 21st Century Black Turbo." Saab USA. Sept. 11, 2007. (Nov. 12, 2008)http://www.saabusa.com/saabjsp/about/pr_070911.jsp