1. What is Pedal Ratio?

Pedal ratio is a mechanical advantage calculation that determines the force multiplication in a brake pedal system. It represents the ratio between the pedal arm length and the master cylinder pushrod length, indicating how much force is amplified from the driver's foot to the brake system.

2. How Does the Calculator Work?

The calculator uses the pedal ratio formula:

Where:

• Pedal Arm Length — Distance from pedal pivot point to foot pad (inches)
• Master Cylinder Pushrod Length — Distance from pedal pivot point to master cylinder pushrod attachment (inches)

Explanation: A higher pedal ratio provides more mechanical advantage, requiring less pedal effort but more pedal travel. A lower ratio requires more effort but less travel.

3. Importance of Pedal Ratio

Details: Proper pedal ratio is crucial for optimal brake performance. It affects pedal feel, braking force, and overall vehicle safety. Most vehicles use ratios between 4:1 and 6:1 for balanced performance.

4. Using the Calculator

Tips: Measure both lengths accurately in inches. Pedal arm length is typically measured from the pivot center to the center of the foot pad. Pushrod length is measured from the pivot center to the pushrod attachment point.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical pedal ratio for passenger vehicles?
A: Most passenger vehicles use pedal ratios between 4:1 and 6:1, with 5:1 being common for balanced pedal effort and travel.

Q2: How does pedal ratio affect brake performance?
A: Higher ratios reduce pedal effort but increase travel distance. Lower ratios increase effort but decrease travel. The ratio must be balanced with master cylinder size for optimal performance.

Q3: Can I change my vehicle's pedal ratio?
A: Yes, but it requires careful engineering. Changing the pushrod attachment point or pedal arm design can alter the ratio, but this affects the entire brake system balance.

Q4: What happens if the pedal ratio is too high?
A: Excessive pedal ratio can cause too much pedal travel, potential bottoming out, and reduced brake feel and modulation.

Q5: How does pedal ratio relate to brake bias?
A: While pedal ratio affects overall force multiplication, brake bias is primarily determined by the master cylinder bore sizes and caliper piston areas in proportion to front/rear weight distribution.