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Performance Calculators

A collection of performance calculators we use every day.
Click a calculator to expand it and enter your values.

Engine & Power

Trap-speed horsepower, boost gains, and track-time projections.

Horsepower Calculator
Boost Horsepower Gain Estimator
Accounts for heat, intercooler losses, fueling, and timing. Typical street setups run 75–90% efficient; a well-cooled race setup can run higher.
1/8 Mile to 1/4 Mile Calculator
Estimate only, using widely used correlation factors from eighth-mile to quarter-mile data. Real results depend on gearing, aero, and how hard the car keeps pulling past the eighth-mile mark.
Fuel System

Injector sizing and pump capacity for your target power level.

Fuel System Capacity Calculator
Boost is used to estimate rail pressure and pump/injector pressure effects, not fuel demand.
Drivetrain & Gearing

Converter slip, gear selection, and RPM-to-speed relationships.

Converter Slip Calculator
Optimal Rear Gear Calculator
RPM at Speed Calculator
No converter slip factored in — this is theoretical RPM at that gear and tire combination. Pair with the Converter Slip Calculator above for a real-world number.
Wheels & Tires

Convert sidewall markings into the numbers the gearing calculators need.

Tire Size to Diameter Calculator
Read straight off the sidewall, e.g. 275/60R15 = 275mm width, 60% aspect ratio, 15" rim.
Accessory Drive

Belt length for your pulley setup.

Belt Size Calculator

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