Turbo Size Calculator

Calculate optimal turbocharger size for your engine build

Turbo Size Calculator

Engine displacement in liters

Current naturally aspirated horsepower

Desired horsepower with turbo

Engine redline RPM

Desired boost pressure in PSI

Turbocharger Basics

A turbocharger uses exhaust gases to drive a turbine that compresses intake air, allowing more fuel to be burned and increasing engine power. Understanding the key components helps in proper sizing:

  • Compressor Wheel: Compresses intake air to increase density
  • Turbine Wheel: Driven by exhaust gases to power the compressor
  • Bearing System: Supports the rotating assembly (shaft)
  • Housing: Contains and directs airflow through the turbo
  • Wastegate: Controls boost pressure by bypassing exhaust flow

Turbo Sizing Factors

Several factors influence turbocharger sizing for optimal performance:

  • Engine Displacement: Larger engines typically need larger turbos
  • Power Goals: Higher power targets require more airflow capacity
  • RPM Range: Operating range affects spool characteristics
  • Boost Pressure: Higher boost requires more compressor efficiency
  • Application: Street vs. track use affects size requirements
  • Response vs. Peak Power: Balance between lag and maximum output

Our calculator considers these factors to recommend appropriate turbo sizing for your specific application.

Turbocharger Frame Sizes

Turbochargers are categorized by frame sizes that indicate their overall capacity:

T25/T28 (Small Frame): 1.0-2.5L engines, up to 300hp, quick spool
T3/T34 (Medium Frame): 2.0-3.5L engines, up to 450hp, balanced performance
T4/T04 (Large Frame): 3.0-5.0L engines, up to 600hp, high-end power
T6/T88 (Extra Large): 4.0L+ engines, 600hp+, race applications

Frame size selection depends on your engine size, power goals, and desired characteristics.

Installation Tips

Successful turbocharger installation requires careful planning and proper execution:

  • Ensure adequate oil supply and return lines for turbo lubrication
  • Install proper heat shielding to protect surrounding components
  • Use quality gaskets and fasteners rated for high temperatures
  • Plan for intercooler placement and piping routing
  • Upgrade fuel system to match increased power requirements
  • Install boost and exhaust gas temperature gauges for monitoring
  • Consider engine management upgrades for proper tuning
  • Allow for proper break-in procedures and oil changes
  • Plan exhaust system modifications for optimal flow

Frequently Asked Questions

What's the difference between compressor and turbine wheel sizes?

The compressor wheel compresses intake air, while the turbine wheel is driven by exhaust gases. Generally, the turbine wheel is slightly larger than the compressor wheel to ensure proper exhaust flow and spool characteristics.

How does turbo lag relate to turbo size?

Larger turbos typically have more lag but can produce more power at high RPM. Smaller turbos spool faster with less lag but may not sustain high power levels. The key is finding the right balance for your application.

What supporting modifications are needed for turbocharging?

Turbocharging typically requires upgraded fuel system, engine management, intercooler, exhaust system, and potentially internal engine components depending on boost levels and power goals.

How accurate are these calculations?

These calculations provide good starting estimates based on industry standards. Final turbo selection should consider specific engine characteristics, intended use, and be verified with a qualified tuner or engineer.