How Much Do Superchargers Increase Horsepower?

Adding a supercharger typically increases a stock engine’s horsepower by about 30–50% at 6–8 psi of boost, while well-supported builds running 10–14 psi can see 50–100% gains. The exact increase depends on boost level, supercharger type, engine strength, fuel quality, intercooling, and tuning. Below, we explain how those variables interact, what typical gains look like in the real world, and what to consider before you bolt one on.

What Determines the Horsepower Gain

Several technical and environmental factors control how much additional power a supercharger can safely and reliably deliver on a given engine. Understanding these helps set realistic expectations.

• Boost pressure: More boost packs in more air. Power scales roughly with the pressure ratio: (14.7 + boost psi) / 14.7, before losses.
• Engine strength and compression: Stock “bottom ends” often tolerate 6–8 psi; higher boost may require forged internals and lower compression.
• Intercooling and intake air temperature: Cooler, denser air makes more power and resists knock; heat soak reduces gains.
• Fuel quality and octane: 93-octane or E85 supports more timing and boost than 91-octane; poor fuel limits power.
• Supercharger type and efficiency: Centrifugal units are often more thermally efficient at high rpm; roots/twin-screw deliver more low-end torque.
• Parasitic drive loss: Belt-driven blowers consume power to make power, typically 6–12% of crank output or 20–60 hp depending on size and speed.
• Altitude: Higher elevation lowers absolute manifold pressure; expect smaller gains unless you pulley for more boost.
• Tuning quality: Conservative tunes protect the engine but may sacrifice peak numbers; aggressive tunes can make more power at higher risk.
• Intake/exhaust flow: Restrictive intake, cats, or exhaust will cap gains; freer-flowing systems help realize boost potential.
• Crank vs wheel horsepower: Drivetrain losses (10–20%) mean dyno wheel hp gains are smaller than crank hp claims.

Taken together, these variables explain why the same supercharger kit can net very different results across engines and climates, and why careful calibration matters as much as hardware.

Typical Gains by Boost Level

The following ranges reflect intercooled street setups on healthy engines using appropriate fuel and a safe tune. They incorporate typical efficiency and parasitic losses and are expressed as approximate crank horsepower increases.

• About 5 psi: roughly 20–30% increase.
• 6–8 psi: roughly 30–50% increase (common for stock internals).
• 9–10 psi: roughly 45–65% increase (often requires upgraded fueling and careful tuning).
• 12–14 psi: roughly 60–100% increase (generally for built engines with robust cooling and fueling).

These are guideposts, not promises; exact results vary with engine displacement, octane, intercooling, ambient temperature, and blower size/speed.

How to Estimate the Gain

A quick way to ballpark crank horsepower is: Estimated HP ≈ Stock HP × [(14.7 + boost psi) / 14.7] × efficiency factor − parasitic loss. For an intercooled street setup, an overall efficiency factor of 0.85–0.95 is typical; parasitic loss can range from 20–60 hp on modest systems to higher on big blowers. Example: a 300 hp engine at 7 psi with 0.9 efficiency and 30 hp parasitic loss yields ≈ 300 × 1.476 × 0.9 − 30 ≈ 368 hp, a ~23% gain. Many V8 kits exceed this because they spin larger, more efficient units and can run more timing on good fuel.

Real-World Kit Examples

Manufacturers’ published ratings and common dyno results provide useful context for what you might see from a mainstream, intercooled supercharger kit on pump gas.

• Ford 5.0L Coyote (2024–2025 Mustang GT): Whipple and Roush 50‑state kits on 91–93 octane are typically rated around 700–750 hp from a 480 hp base, a ~45–55% increase at 7–9 psi.
• Chevy 6.2L LT1 (Camaro SS): Magnuson TVS2650 or ProCharger P‑1SC intercooled systems at ~7–8 psi commonly deliver 630–650+ hp from ~455 hp stock, about 35–45% more.
• Toyota GR86/Subaru BRZ (2.4L FA24): Centrifugal or twin‑screw kits at 6–9 psi often raise output from ~228 hp to ~300–340 hp, roughly 30–50% gains with intercooling and 93 octane.
• Mazda MX‑5 Miata ND (2.0L): Intercooled roots/twin‑screw kits typically move from ~181 hp to ~240–260 hp on pump gas, a ~30–45% increase.

These examples illustrate the pattern: modest boost on modern, efficient engines reliably yields 30–50% more power, with higher gains possible as supporting modifications and octane improve.

Roots vs. Twin‑Screw vs. Centrifugal

Different supercharger architectures change how and where power is added, affecting the driving feel as much as the peak number.

• Roots: Delivers near‑instant boost and strong midrange; simple packaging on V engines. Can run warmer IATs at higher rpm, which may limit sustained top‑end power without excellent cooling.
• Twin‑screw: Positive displacement like roots but generally higher adiabatic efficiency; strong low‑to‑mid torque and better high‑rpm than traditional roots units.
• Centrifugal: Boost rises with rpm; often the coolest charge temps and lowest parasitic losses for high‑rpm power. Feels turbo‑like, with less low‑rpm surge but strong top‑end.

At the same safe manifold pressure, peak horsepower potential is similar, but charge temperature, efficiency, and boost curve shape influence real‑world results and heat management.

Reliability, Fuel, and Legal Considerations

To make the added power safely and keep it, most builds need more than a blower head unit. The following supporting items are commonly required or recommended.

• High‑flow fueling: Bigger injectors, upgraded pump(s), and proper fuel pressure control.
• Intercooling and cooling: Air‑to‑air or air‑to‑water intercoolers, heat exchangers, and sometimes radiator or oil cooler upgrades.
• Ignition and tune: Quality ECU calibration matched to your fuel (91/93/E85) and hardware, with knock control and safe timing.
• Exhaust and intake: Reduced restriction to manage backpressure and temperature.
• Engine and drivetrain: For higher boost, forged pistons/rods, clutch/converter, and stronger transmissions/axles may be needed.
• Emissions and compliance: In emissions‑regulated regions, look for kits with a CARB EO number for street legality.

Planning these elements alongside the blower choice prevents expensive mistakes and maximizes reliable, repeatable performance.

Crank vs. Wheel Horsepower

Manufacturers usually quote crank horsepower (engine dyno or calculated), while enthusiasts often talk in wheel horsepower (chassis dyno). Expect 10–20% drivetrain loss depending on transmission, differential, and tires. A 40% crank increase might look like a 30–35% wheel increase on a chassis dyno, which is normal.

Bottom Line

On pump gas with an intercooled, well‑tuned setup, superchargers commonly add 30–50% more horsepower at 6–8 psi on stock engines and 50–100% at higher boost with the right supporting mods. The precise gain hinges on boost, blower type, engine health, fuel, intercooling, and tuning quality.

How much horsepower does a whipple supercharger add to a 5.0 F-150?

A Whipple supercharger can add between approximately 725 to over 800 horsepower to a 5.0L F-150, depending on the specific kit and model year. The exact amount of horsepower and torque varies by stage and features, with Stage 1 kits typically yielding around 725 HP and Stage 2 kits producing upwards of 805 HP, using 93 octane fuel. 
Whipple Supercharger Power Gains by Stage (for recent models like 2024-2025)

• Stage 1: Delivers up to 725 HP and 650 lb-ft of torque. 
• Stage 2: Delivers up to 805 HP and 685 lb-ft of torque. 

Factors Influencing Horsepower

• Kit Stage: Higher stages, like Stage 2, include more components such as a larger throttle body and injectors, resulting in greater power gains. 
• Octane Fuel: The power figures provided are typically based on the use of 93 octane (premium) fuel. 
• Intercooler Technology: Whipple’s advanced, patented dual-pass intercooler systems significantly improve thermal efficiency, helping to maintain consistent power. 
• PCM Calibration: The kits include optimized engine calibrations to manage the increased power and ensure drivability. 
• Upgrades for More Power: For even higher output, additional pulleys and supporting hardware can boost power even further, potentially reaching 900 HP. 

How much horsepower will a supercharger add to a 5.7 L Hemi?

The 5.7L HEMI Dodge Charger Supercharger Kit
Dyno testing showed that a stock 5.7 HEMI Dodge Charger produced 320 rear-wheel WHP. After we installed a RIPP Supercharger, we safely made 528 WHP! and 504 ft/lbs torque. This is the most powerful bolt-on supercharger kit on the market and the most cost-effective.

How much HP is 5 psi of boost?

Adding 5 PSI of boost to atmospheric 14.7 PSI, you get about a 34% increase in oxygen (19.7 PSI vs 14.7 PSI), or you would do roughly 260 HP in an engine that made 200 HP beforehand. Boost + increased compression ratio is a bad, BAD thing.

How much does a supercharger increase HP?

A supercharger can increase an engine’s horsepower by 30% to 50% or more, depending on the vehicle’s stock output, the type of supercharger, and whether other engine components have been upgraded to handle the added power. While it forces more air into the engine to burn more fuel and create more power, it also consumes some power from the engine’s crankshaft to operate.
 
Key Factors Affecting HP Gains

• Stock Engine Output: Opens in new tabThe original horsepower of the engine sets the baseline. A supercharger will add a percentage of this original power. 
• Supercharger Type and Boost: Opens in new tabDifferent supercharger types (like Roots, twin-screw, or centrifugal) produce different levels of “boost” (compressed air pressure) and have varying efficiencies. 
• Other Engine Modifications: Opens in new tabTo maximize potential and ensure reliability, other engine components often need upgrades, such as improved exhaust systems, intercoolers, or even more robust engine internals. 
• Parasitic Power Loss: Opens in new tabBecause the supercharger is belt-driven, it draws power directly from the engine’s crankshaft, which reduces the net horsepower gain. 

Examples of Power Gains

• A supercharger kit can add anywhere from 35% to over 50% more horsepower and torque. 
• For some engines, such as a stock 5.7L HEMI, power gains of over 160 HP are achievable. 
• Aftermarket systems can provide a significant boost, with examples showing gains of 200 or more horsepower on cars like a Mustang GT.