Cylinder Head Flow Calculator

Estimate horsepower potential from flow bench data and analyze port efficiency.

Peak flow at max lift
For E/I ratio analysis

Flow Bench Guidelines

ApplicationIntake CFM~HP/Cyl
Stock Street170-200 CFM45-55 HP
Mild Performance220-260 CFM60-70 HP
Street/Strip270-310 CFM70-85 HP
Race Ported320-380 CFM85-100 HP
Pro Stock400+ CFM100+ HP

*At 28" H2O test pressure, naturally aspirated, optimized combo

E/I Ratio Guidelines

Exhaust/Intake flow ratio target:

  • Street: 70-75%
  • Performance: 75-80%
  • Race: 80-85%