1. What is a Fuel Injector Flow Calculator?

Definition: This calculator estimates the required fuel injector flow rate based on engine horsepower, brake specific fuel consumption (BSFC), number of injectors, and duty cycle.

Purpose: It helps automotive professionals and enthusiasts determine the proper fuel injector size for engine modifications or upgrades.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Flow \) — Fuel injector flow rate (pounds per hour)
• \( HP \) — Engine horsepower
• \( BSFC \) — Brake specific fuel consumption (lb/HP·hr)
• \( N \) — Number of fuel injectors
• \( DC \) — Duty cycle (0-1, typically 0.8 for 80%)

Explanation: The formula calculates how much fuel each injector needs to deliver based on total engine requirements and operating parameters.

3. Importance of Fuel Injector Flow Calculation

Details: Proper fuel injector sizing ensures optimal engine performance, prevents lean conditions, and maintains fuel efficiency.

4. Using the Calculator

Tips: Enter engine horsepower, BSFC (default 0.5 lb/HP·hr for NA gasoline), number of injectors (default 4), and duty cycle (default 0.8). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is BSFC and how do I determine it?
A: Brake Specific Fuel Consumption measures fuel efficiency. Typical values: 0.45-0.55 for NA gasoline, 0.55-0.65 for turbo gasoline, 0.35-0.45 for diesel.

Q2: Why is duty cycle important?
A: It represents the percentage of time injectors are open. Running above 80% can cause overheating and inconsistent fuel delivery.

Q3: What if I have a different number of injectors?
A: Adjust the "N" value accordingly. Some engines use 6, 8, or more injectors.

Q4: How do I convert lb/hr to cc/min?
A: Multiply lb/hr by 10.5 to get cc/min (approximately).

Q5: Should I add a safety margin?
A: Yes, consider selecting injectors 10-20% larger than calculated to allow for future upgrades.