How does boost pressure relate to power?

Boost pressure increases the air charge in the cylinders, allowing more fuel to be burned. Theoretically, doubling the air (14.7 PSI boost) would double the power, but real-world gains are less due to intercooler efficiency, exhaust backpressure, and engine management.

What is typical turbo efficiency?

Modern turbochargers achieve 70-80% efficiency. This means about 70-80% of the theoretical power gain is actually realized. Intercooler efficiency, exhaust restrictions, and engine tuning all affect the final figure.

What is a safe boost level?

This depends entirely on the engine internals. Stock turbocharged engines are typically safe at factory boost levels. Adding 2-3 PSI above stock is usually safe with supporting modifications. Higher boost requires stronger internals, better fueling, and proper tuning.

How much power does a turbo add?

A turbo can increase engine power by 30-50% or more. The exact gain depends on boost pressure, intercooler efficiency, fuelling, and the engine strength. A 1.0-litre turbo engine can produce as much power as a 1.5-1.6 naturally aspirated engine.

Turbo lag is the delay between pressing the accelerator and the turbo delivering full boost. It occurs because the exhaust gases need time to spin the turbine up to speed. Modern twin-scroll turbos and variable geometry turbines have reduced lag significantly compared to older designs.

CarCalcs

Turbo Boost Calculator

Estimate power gains from turbo boost pressure.

Base NA Power

Naturally aspirated power or current power

Boost Pressure

Turbo Efficiency

Typical: 70-80%

How We Calculate This

Power gain is proportional to the pressure ratio (boost + atmospheric / atmospheric) multiplied by turbo efficiency. This gives a theoretical estimate that is generally close to real-world results with proper tuning.

Frequently Asked Questions

Related Calculators

BHP to KW Converter

Convert between brake horsepower and kilowatts.

Torque Converter

Convert torque between Nm, lb-ft, and kgf-m.

0-60 Calculator

Estimate 0-60 mph time from power, weight, and drivetrain.

Power to Weight Calculator

Calculate your car's power-to-weight ratio in BHP per tonne.

Quarter Mile Calculator

Estimate quarter mile time and trap speed from power and weight.

Last updated: February 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.