Boost to HP Calculator – Calculate Horsepower from Boost PSI

HP_Boosted = HP_NA × (1 + (Boost_PSI / 14.7)), this boost to hp calculator is created to estimate the increase in horsepower (HP) based on the amount of boost pressure applied to an engine

For Boost = 2 psi, Efficiency Factor = 0.8:
HP Increase = 200 × (2 /14.7) ×0.8 ≈ 22 HP
Total HP = 200 +22 = 222 HP

For Boost = 6 psi, Efficiency Factor = 0.75:
HP Increase = 200 × (6 /14.7) ×0.75 ≈ 57 HP
Total HP = 200 +57 = 257 HP

Boost to HP Calculator

Boost (psi)	Efficiency Factor	HP Increase	Total HP
2	0.8	22.0	222
5	0.7	47.6	247.6
6	0.75	57.1	257.1
8	0.7	76.2	276.2
10	0.7	95.2	295.2
12	0.65	106.1	306.1
15	0.6	122.4	322.4
18	0.55	138.7	338.7
20	0.5	152.5	352.5
25	0.45	179.8	379.8
30	0.4	203.3	403.3

Boost to Horsepower Conversion Formula

The conversion formula often used is:

HP Increase = Base HP × (Boost Pressure / 14.7) × Efficiency Factor

Where:

• Base HP is the engine’s horsepower without boost
• Boost Pressure is measured in psi (pounds per square inch)
• 14.7 represents atmospheric pressure at sea level (in psi)
• Efficiency Factor accounts for system losses (typically 0.6 to 0.8)

A 200 HP engine with 10 psi boost and 0.7 efficiency factor

HP Increase = 200 × (10 / 14.7) × 0.7 ≈ 95 HP

Total HP = 200 + 95 = 295 HP

How to Convert Boost to HP?

To convert boost to HP:

• Determine your engine’s base horsepower
• Measure the boost pressure in psi
• Choose an appropriate efficiency factor
• Apply the formula mentioned above

180 HP engine, 8 psi boost, 0.65 efficiency

HP Increase = 180 × (8 / 14.7) × 0.65 ≈ 63.7 HP

Total HP = 180 + 63.7 ≈ 244 HP

How much HP does a boost add?

Generally, each psi of boost can add 4-8% of the base horsepower.

The HP added by boost varies significantly based on factors like engine displacement, fuel system, and intercooler efficiency.

A 250 HP engine with 6 psi boost Estimated HP gain: 250 × 0.06 × 6 = 90 HP Total HP: 250 + 90 = 340 HP

How much HP is 1 psi of boost?

One psi of boost typically adds 4-8% of the base horsepower.

A 300 HP engine with 1 psi boost (using 6% estimate) HP gain: 300 × 0.06 = 18 HP Total HP: 300 + 18 = 318 HP

How much HP is 5 psi of boost?

A 5 psi of boost could add 20-40% of the base horsepower.

A 220 HP engine with 5 psi boost (using 7% per psi estimate) HP gain: 220 × 0.07 × 5 = 77 HP Total HP: 220 + 77 = 297 HP

What is boost for horsepower?

Boost refers to the increase in air pressure above atmospheric pressure in an engine’s intake system. This increased pressure, typically provided by turbochargers or superchargers, allows more air and fuel to enter the combustion chamber, resulting in higher power output.

A turbocharger spinning at 100,000 RPM might generate 12 psi of boost, potentially increasing a 180 HP engine to over 250 HP, depending on other factors.

References

• CarThrottle: The Pros And Cons Of Turbocharging Vs Supercharging

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