Wheel Torque To Crank Torque Calculator

Wheel Torque To Crank Torque Formula:

\[ T_{crank} = \frac{T_{wheel}}{(gear\_ratio \times final\_drive \times efficiency)} \]

Wheel Torque (T_wheel):

Gear Ratio:

dimensionless

Final Drive:

dimensionless

Efficiency (eff):

dimensionless

Crank Torque (T_crank):

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1. What Is Wheel Torque To Crank Torque Calculation?

The wheel torque to crank torque calculation determines the torque at the engine's crankshaft based on the measured wheel torque, taking into account gear ratios, final drive ratio, and drivetrain efficiency.

2. How Does The Calculator Work?

The calculator uses the formula:

\[ T_{crank} = \frac{T_{wheel}}{(gear\_ratio \times final\_drive \times efficiency)} \]

Where:

\( T_{crank} \) — Crank torque (Nm)
\( T_{wheel} \) — Wheel torque (Nm)
\( gear\_ratio \) — Current gear ratio (dimensionless)
\( final\_drive \) — Final drive ratio (dimensionless)
\( efficiency \) — Drivetrain efficiency (dimensionless, typically 0.85-0.95)

Explanation: The formula accounts for torque multiplication through the transmission and final drive, while considering energy losses in the drivetrain system.

3. Importance Of Crank Torque Calculation

Details: Calculating crank torque from wheel torque is essential for engine performance analysis, transmission design, and understanding the actual torque output at the engine level.

4. Using The Calculator

Tips: Enter wheel torque in Nm, gear ratio, final drive ratio, and drivetrain efficiency (typically between 0.85-0.95). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is drivetrain efficiency important in this calculation?
A: Drivetrain efficiency accounts for energy losses due to friction, heat, and other factors in the transmission, differential, and drive shafts.

Q2: What are typical efficiency values for different drivetrain types?
A: Manual transmissions: 0.93-0.97, Automatic transmissions: 0.85-0.92, CVT: 0.88-0.92, depending on design and condition.

Q3: How does gear ratio affect crank torque calculation?
A: Higher gear ratios result in lower crank torque values for the same wheel torque, as the transmission provides more torque multiplication.

Q4: Can this calculation be used for electric vehicles?
A: Yes, the same principle applies to electric vehicles, though efficiency values may differ due to different drivetrain characteristics.

Q5: What are common applications of this calculation?
A: This calculation is used in automotive engineering, performance tuning, dyno testing, and vehicle dynamics analysis.