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Ideal Boost-Pressure Power Ratio Estimate

Explore a simple pressure-ratio power estimate with a fixed 14.7 psi ambient reference.

Formula & worked example
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How to use this calculator

Enter the known values in the units shown. Results update as you type.
Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
Use the worked example to check the method. Reset restores the starting fields.

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Formula and method

The ideal model doubles a baseline of 200 mechanical hp to 400 hp at 14.7 psi gauge boost. Actual engine output also depends on temperature, airflow, efficiency and many other conditions.

Estimated power = baseline power × (14.7 psi + gauge boost) / 14.7 psi

Worked example

Enter these known values and leave the other values blank.

Baseline power before the modeled boost: 200 hp(l)
Gauge boost above the fixed ambient reference: 14.7 psi

Ideal pressure-scaled power: 400 hp(l)

Assumptions and limitations

This is a proportional pressure-ratio illustration. It is not an engine simulation, dyno prediction, tuning recommendation or a safe boost limit.
The reference ambient pressure is fixed at 14.7 psi absolute. It is a rounded reference, not an altitude-dependent reading or exactly 101,325 Pa.
The model omits intake heating, volumetric efficiency, intercooler behavior, compressor maps, fuel limits, detonation, backpressure and mechanical losses.
The baseline must correspond to operation before the modeled boost increase. Applying the full ratio to an already boosted baseline can double-count boost.
The retained input range is 0–100 psi gauge boost and baseline power strictly between 1 and 10,000 mechanical hp. These numeric bounds do not certify that a real engine can operate there.

Common questions

Does doubling absolute intake pressure guarantee double power?

No. This simplified model holds other factors constant. Real air temperature, airflow, fueling, losses and engine limits can change the result substantially.

Is the boost field absolute pressure?

No. It is gauge pressure above the fixed 14.7 psi ambient reference. The formula adds that reference before taking the pressure ratio.

References

Pounds-force per square inch use the exact international pound and inch with standard gravity, replacing the rounded captured factor. Mechanical horsepower uses exactly 550 foot-pounds-force per second instead of a rounded factor.

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