1. What is the Turbo Map Formula?

The Turbo Map formula calculates the appropriate turbocharger size by multiplying airflow (in pounds per minute) by the pressure ratio. This helps determine the optimal turbocharger for a given engine setup.

2. How Does the Calculator Work?

The calculator uses the Turbo Map equation:

Where:

• \( Airflow \) — Air mass flow rate in pounds per minute (lbs/min)
• \( Pressure\ Ratio \) — Absolute outlet pressure divided by absolute inlet pressure (decimal)

Explanation: The equation provides a simple way to match turbocharger size to engine requirements based on airflow and desired boost pressure.

3. Importance of Turbo Size Calculation

Details: Proper turbo sizing is crucial for achieving desired performance characteristics while avoiding turbo lag (too large) or overspeeding (too small).

4. Using the Calculator

Tips: Enter airflow in lbs/min (typically 10-100 for most applications) and pressure ratio (typically 1.5-3.5 for street applications). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my engine's airflow?
A: Airflow can be estimated from engine displacement, RPM, and volumetric efficiency, or measured with a mass airflow sensor.

Q2: What is a typical pressure ratio for street cars?
A: Most street applications use pressure ratios between 1.5 and 2.5 (approximately 7-22 psi of boost).

Q3: How does this relate to turbo selection?
A: The calculated value helps identify where your requirements fall on a compressor map when selecting a turbo.

Q4: Are there other factors to consider?
A: Yes, including exhaust flow characteristics, desired spool time, and intended use (street, track, drag, etc.).

Q5: What about turbo efficiency?
A: This calculator provides a basic size estimate. Actual selection should consider the turbo's efficiency island on its compressor map.