1. What is the Exhaust Diameter Formula?

The exhaust diameter formula calculates the optimal diameter for an exhaust system based on engine volume, RPM, maximum exhaust gas speed, and a constant that accounts for various factors in exhaust flow dynamics.

2. How Does the Calculator Work?

The calculator uses the exhaust diameter equation:

Where:

• \( V \) — Volume of exhaust gases (m³)
• \( RPM \) — Engine revolutions per minute
• \( max\ speed \) — Maximum exhaust gas speed (m/s)
• \( constant \) — Empirical constant (typically 88.4)

Explanation: The equation balances exhaust gas volume flow rate with desired velocity to determine optimal pipe diameter.

3. Importance of Proper Exhaust Sizing

Details: Correct exhaust diameter is crucial for engine performance, affecting backpressure, scavenging efficiency, and overall engine power output.

4. Using the Calculator

Tips: Enter volume in cubic meters, RPM in revolutions per minute, maximum speed in meters per second, and the appropriate constant. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical value for the constant?
A: The constant typically ranges from 88.4 to 100, depending on the specific application and desired exhaust gas velocity.

Q2: How does exhaust diameter affect performance?
A: Too small diameter increases backpressure, reducing power. Too large diameter reduces exhaust velocity, hurting scavenging.

Q3: What is a typical max exhaust gas speed?
A: Typically between 90-120 m/s for naturally aspirated engines, up to 150 m/s for high-performance applications.

Q4: Should I use the same diameter for the entire exhaust?
A: Often a stepped system works best, with diameter increasing after the header to maintain proper velocity as gases cool.

Q5: How does this apply to turbocharged engines?
A: Turbocharged systems have different requirements due to the turbine's effect on exhaust flow dynamics.