1. What is a Fuel Injector Pulse Width Calculator?

Definition: This calculator determines the injector pulse width (duration) needed based on fuel flow rate, duty cycle, and engine speed.

Purpose: It helps automotive technicians and tuners optimize fuel delivery for engine performance and efficiency.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( PW \) — Pulse width (milliseconds)
• \( Flow \) — Injector flow rate (lb/hr)
• \( DC \) — Duty cycle (0-1, typically 0.8-0.9 max)
• \( RPM \) — Engine speed (revolutions per minute)

Explanation: The formula calculates how long the injector needs to stay open to deliver the required fuel amount at a given engine speed.

3. Importance of Pulse Width Calculation

Details: Proper pulse width calculation ensures correct air-fuel mixture, prevents lean/rich conditions, and helps avoid injector overuse.

4. Using the Calculator

Tips: Enter injector flow rate in lb/hr, duty cycle (default 0.8), and engine RPM. All values must be > 0, with duty cycle between 0-1.

5. Frequently Asked Questions (FAQ)

Q1: What is injector duty cycle?
A: The percentage of time the injector is open during an engine cycle (0 = always closed, 1 = always open).

Q2: Why is the 2/60 factor used?
A: It converts RPM to revolutions per millisecond and accounts for 4-stroke engines (inject once every 2 revolutions).

Q3: What's a typical injector flow rate?
A: Stock injectors range 15-30 lb/hr, while performance injectors can be 50-200+ lb/hr.

Q4: When would pulse width be too long?
A: If calculated PW exceeds available time at given RPM (duty cycle > 1), you need larger injectors.

Q5: How does RPM affect pulse width?
A: Higher RPM means less time available per cycle, requiring shorter pulse widths for same fuel delivery.