Turbo Sizing Calculator

Calculate required turbocharger mass flow (lb/min) and pressure ratio for a given horsepower target.

How It Works

Enter target horsepower, BSFC, air-fuel ratio, and volumetric efficiency. The calculator determines compressor mass flow rate and pressure ratio to help select an appropriately sized turbocharger.

Formula

Mass Flow (lb/min) = (HP x BSFC) / (AFR x 60)

Frequently Asked Questions

How do I read a turbo compressor map?

A compressor map plots pressure ratio (y-axis) against mass flow (x-axis). Your operating point should fall within the efficiency island, away from the surge line (left) and choke line (right).

What is the difference between a T3 and T4 turbo?

T3/T4 refer to turbine housing inlet flange sizes. T3 housings flow less exhaust and spool faster; T4 housings flow more for higher power but spool more slowly. Match the turbine to your power and RPM target.