Engine & Performance

Horsepower and torque, displacement, compression, fuelling, boost and the empirical 0–60 and quarter-mile estimates.

• 0–60 Time Calculator An empirical 0–60 mph and 0–100 km/h estimate from power and weight. Within about a second for most road cars; it is a fit to data, not a simulation.
• Air-Fuel Ratio Calculator Converts between air-fuel ratio and lambda for any fuel, and says whether a mixture is rich or lean and what that means.
• Boost Pressure Calculator Pressure ratio, absolute manifold pressure and a rough power estimate for a given boost, with the psi, bar and kPa conversions.
• Compression Ratio Calculator Static compression ratio from bore, stroke, chamber volume, gasket, deck height and piston dish or dome — the full calculation, not the rule of thumb.
• Engine Displacement Calculator Engine displacement from bore, stroke and cylinder count — in cc, litres and cubic inches — plus the effect of a rebore or stroker crank.
• Fuel Injector Size and Duty Cycle Calculator The injector flow rate an engine needs for a target power, and the duty cycle your current injectors would run at.
• Horsepower and Torque Calculator Converts between horsepower and torque at a given rpm, in both metric and imperial units — the 5,252 rule and its metric equivalent.
• Power-to-Weight Ratio Calculator Power-to-weight ratio in kW per tonne, hp per ton, W/kg and kg per hp — the figure that predicts acceleration better than power alone.
• Quarter Mile Calculator Estimated quarter-mile elapsed time and trap speed from power and weight, using the standard empirical formulas.
• Volumetric Efficiency Calculator Volumetric efficiency from measured airflow, displacement and rpm — or the airflow an engine needs at a given VE, for sizing intakes and carburettors.