1. What is Portal Gears Ratio?

The Portal Gears Ratio is the final drive ratio achieved when combining axle gearing with portal axle reduction. It determines the torque multiplication and speed reduction in vehicles equipped with portal axles.

2. How Does the Calculator Work?

The calculator uses the Portal Gears Ratio formula:

Where:

• Axle Gear Teeth — Number of teeth on the ring gear
• Pinion Gear Teeth — Number of teeth on the pinion gear
• Portal Reduction Ratio — The reduction ratio of the portal box (e.g., 1.5:1, 2.0:1)

Explanation: The equation first calculates the standard axle ratio, then multiplies it by the portal reduction to get the final drive ratio.

3. Importance of Gear Ratio Calculation

Details: Proper gear ratio selection is crucial for vehicle performance, affecting torque, top speed, fuel efficiency, and drivetrain stress.

4. Using the Calculator

Tips: Enter the number of teeth for both gears and the portal reduction ratio. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical portal reduction ratios?
A: Common ratios are 1.5:1, 1.7:1, and 2.0:1, depending on the portal axle manufacturer.

Q2: How does portal ratio affect tire size?
A: Higher ratios allow for larger tires without losing too much torque, as they compensate for the increased leverage.

Q3: What's the difference between this and standard axle ratio?
A: Standard ratio only considers ring and pinion gears, while portal ratio includes the additional reduction from the portal boxes.

Q4: When would I need to calculate this?
A: When planning drivetrain modifications, changing tire sizes, or selecting gear ratios for optimal performance.

Q5: How does this affect fuel economy?
A: Higher final ratios generally decrease fuel economy at highway speeds but improve low-speed torque.