What is Torque vectoring Differential?

In this article, we explain torque vectoring differential, its working, animation in detail.

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What Is a Torque Vectoring Differential?

A Torque Vectoring Differential (TVD) is an advanced, electronically controlled differential system that can actively distribute torque between the left and right wheels (and sometimes between front and rear axles) independently, based on driving conditions.

In simple terms:
While an LSD limits slip and a locker forces equal torque,
a torque vectoring differential intelligently decides how much torque to send to each wheel for optimal grip and cornering.

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Purpose of Torque Vectoring Differential:

The main goal of a torque vectoring differential is to:

• Improve traction
• Enhance cornering performance
• Increase vehicle stability
• Reduce understeer or oversteer
• Maximize acceleration through turns

In other words, it doesn’t just react to wheel slip — it predicts and controls torque distribution to improve handling dynamics.

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Basic Construction

A torque vectoring differential builds upon a limited-slip differential (LSD) design but adds electronic sensors, clutches, and actuators to actively control torque split.

🔩 Main Components

1. Differential Case – Houses the differential gears.
2. Side Gears and Spider Gears – Perform basic differential action.
3. Multi-Plate Clutch Packs – One for each axle shaft (left and right wheel).
4. Actuators (Hydraulic or Electric) – Control the engagement of each clutch.
5. Electronic Control Unit (ECU) – Brain of the system; processes sensor inputs and controls actuators.
6. Sensors – Measure parameters like:
   • Wheel speeds (from ABS sensors)
   • Steering angle
   • Throttle position
   • Yaw rate
   • Lateral and longitudinal acceleration

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Working Principle:

Let’s understand how a Torque Vectoring Differential operates under various conditions:

1. Straight-Line Driving

• Both wheels rotate at the same speed.
• ECU detects minimal steering input and yaw rate.
• Clutches are partially disengaged — torque is split evenly.

➡️ Acts like a normal differential.

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2. Cornering (Turning)

When a car turns, the outer wheel travels a longer distance than the inner wheel — it must rotate faster.

In traditional systems:

• Open diff: equal torque → less traction.
• LSD: limits slip but not fully optimized.

But in TVD:

• ECU predicts the turn (using steering angle + yaw sensors).
• It preemptively sends more torque to the outer wheel, which:
  • Helps “push” the car around the corner.
  • Increases yaw rate.
  • Reduces understeer.

This effect is similar to rear-wheel steering, but achieved through torque control rather than steering geometry.

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3. Slippery or Uneven Surfaces

• If one wheel loses traction, ECU applies more clutch pressure on the wheel with better grip.
• Torque is redistributed instantly.

➡️ Maintains traction and vehicle stability even on low-friction roads.

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Torque Distribution Logic

Depending on design and manufacturer:

• Torque bias ratio can be as high as 80:20 or 100:0 between left and right wheels.
• Some systems even send all torque to a single wheel temporarily to improve cornering or recovery.

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Types of Torque Vectoring Differentials

There are two main categories based on drivetrain layout:

1. Axle-Based Torque Vectoring (Left–Right)

• Installed on the rear or front axle.
• Controls torque distribution between left and right wheels on the same axle.

Example:

• Audi Sport Differential (Quattro system)
• BMW M Active Differential
• Lexus RC F and LC 500 TVD

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2. Powertrain-Based Torque Vectoring (Front–Rear + Side–Side)

• Used in AWD systems.
• Distributes torque between axles (front vs rear) and between wheels on each axle.

Example:

• Acura SH-AWD (Super Handling AWD)
• Nissan GT-R ATTESA E-TS system
• Ford Focus RS AWD TVD

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How Torque Vectoring Enhances Cornering

Let’s visualize cornering on a right-hand turn:

• The outer left wheel travels farther and needs more torque.
• The inner right wheel travels less and needs less torque.

TVD sends more torque to the outer wheel, generating a yaw moment that helps rotate the vehicle into the turn.

This is often described as “torque-induced yaw control.”

➡️ Result:

• Sharper turn-in
• Less understeer
• Improved stability and agility

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Electronic Control Strategy

The ECU continuously monitors:

• Steering angle
• Vehicle speed
• Yaw rate
• Throttle/brake position
• Wheel speeds

Then it calculates desired torque vectoring and commands the actuators accordingly — up to hundreds of times per second.

This integration with the ESC (Electronic Stability Control) and ABS systems ensures that torque vectoring complements braking and traction control seamlessly.

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Advantages

✅ Superior traction under all conditions
✅ Enhanced cornering performance (reduces understeer)
✅ Improved stability during acceleration and braking
✅ Active yaw control — car feels more agile and balanced
✅ Adaptive behavior — responds to driver style and road surface

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Disadvantages

❌ Complex and expensive (requires sensors, actuators, ECU)
❌ Heavier than traditional diffs (adds weight)
❌ Higher maintenance and repair costs
❌ Software-dependent — can fail if electronics malfunction

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Applications in Modern Vehicles

Vehicle	System Name	Description
Audi S/RS models	Audi Sport Differential	Actively distributes torque across rear axle
BMW M series	Active M Differential	Electronically controlled clutch packs
Acura NSX / SH-AWD	Torque Vectoring AWD	Varies torque front/rear and side/side
Nissan GT-R	ATTESA E-TS	Dynamic AWD torque vectoring
Ford Focus RS	Dynamic AWD TVD	Uses twin clutch packs for rear torque control
Lexus RC F / LC 500	TVD	Driver-selectable torque vectoring modes

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Comparison: TVD vs Other Differentials

Feature	Open Diff	LSD	Locking Diff	Torque Vectoring Diff
Torque Distribution	Equal	Variable (limited)	Equal (locked)	Actively variable (controlled)
Speed Difference	Free	Limited	None when locked	Controlled electronically
Traction	Poor	Good	Excellent (off-road)	Excellent (on-road performance)
Handling	Smooth	Stable	Hard to steer	Agile and responsive
Control	Passive	Semi-active	Manual/auto	Fully active (ECU controlled)
Cost	Low	Medium	High	Very high

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Summary

Aspect	Description
Definition	Electronically controlled differential that distributes torque between wheels actively
Purpose	Improve traction, cornering, and stability
Mechanism	Uses clutch packs, actuators, and sensors controlled by ECU
Operation	Sends more torque to the outer wheel during cornering
Applications	High-performance and AWD vehicles
Advantages	Maximum grip, agility, and stability
Disadvantages	Complex, costly, heavier

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FAQ Section:

What is a Torque Vectoring Differential?
It’s an advanced differential that actively distributes torque between wheels to improve traction, stability, and handling.

How does a Torque Vectoring Differential work?
It uses electronic sensors and actuators to control torque flow, sending more power to the wheel that can best use it.

What’s the difference between Torque Vectoring and LSD?
Unlike an LSD, which passively limits slip, torque vectoring actively manages torque using electronic controls for faster response and precision.

What are the benefits of Torque Vectoring?
It enhances cornering performance, improves grip, reduces understeer or oversteer, and increases driving stability.

Is Torque Vectoring only for sports cars?
No, it’s also used in SUVs and performance sedans to improve handling and safety in various driving conditions.

Does Torque Vectoring improve acceleration?
Yes, by directing torque to the wheels with the most grip, it helps maintain traction and faster corner exits.

How is Torque Vectoring controlled?
It’s typically managed by the vehicle’s ECU, using data from sensors like steering angle, yaw rate, and wheel speed.

Is Torque Vectoring available in both AWD and FWD cars?
Yes, it’s used in both systems, though it’s more common in AWD vehicles for optimal power distribution.

Does Torque Vectoring require maintenance?
It generally requires minimal maintenance, but periodic fluid checks and software updates may be needed.

Can Torque Vectoring be retrofitted to older vehicles?
Not easily — it’s an integrated system requiring advanced electronics and drivetrain components designed into the vehicle.

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