TC, VSC, Drive Mode, and the LSD in the Supra

[Nocturnal LE]

Being my first car with a lot of these nannies, I’ve become interested in how they work (from a functional perspective). Most of this info is generic, but my hope is that those experienced with track/HPD driving can comment on these specific systems in the Surpa, especially compared to other vehicles they have driven.

Traction control (TC): Monitors wheel slippage. When wheel slippage occurs, sensors send this info to the ECU, and in turn the ECU cuts power from the engine and/or activates the brakes on the side that is slipping. EXAMPLE: Trying to do a burnout - TC will cut power and/or brake the slipping wheels.

Vehicle Stability Control (VSC): Monitors 3 things: steering angle, yaw angle, how fast the wheels are turning. EXAMPLE: Oversteer condition. ECU recognizes from these sensors that steering angle and yaw angle are different, and will brake the outside FRONT wheel. Car will pivot around this outside front wheel to straighten the car. An understeer condition would brake the inside REAR wheel.

Drive mode (Sport Button): My understanding is the TC and ESC will be dialed back slightly. I’ve read that it “sharpens the rear differential.” Can anyone confirm / deny?

LSD: Independent of TC, VSC, and drive mode. Cannot be turned off (nor would you want to). The supra has an electronically actuated, clutch-type rear LSD (electro-mechanical). The LSD can shift power between 0-100% to the rear wheels. EXAMPLE: Cornering left near the cars limit, a greater percentage of the power is sent to the rear outside wheel which has more traction.

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[Hardac_]

I stumbled on this post when specifically searching how the rear diff changes with VCS off. Anecdotally the rear feels like it has much more rotation in tighter corners, it's even gotten to the point that I now daily it with it turned off.