A centrifugal supercharger is a belt-driven compressor that works like the compressor side of a turbocharger: an impeller spinning at very high speed flings air outward and pressurizes it before it goes to the engine. Because the impeller is geared up from the crankshaft pulley, boost rises with engine speed, building smoothly to its peak near redline. That makes centrifugal superchargers efficient and strong at high RPM, and easy to fit with an intercooler.
How a centrifugal supercharger works
- Drive: a belt from the crankshaft turns the supercharger, and internal gearing steps that speed up many times for the impeller.
- Compression: the impeller accelerates air outward into a scroll-shaped housing, which converts the speed into pressure.
- Intercooling: the pressurized air usually passes through an intercooler before the throttle body; see what does an intercooler do?
- Boost curve: boost climbs with engine speed, so the engine pulls harder the higher it revs.
Centrifugal vs Roots vs twin-screw
| Centrifugal | Roots | Twin-screw | |
|---|---|---|---|
| Type | Dynamic compressor, like a turbo | Positive displacement | Positive displacement with internal compression |
| Boost delivery | Rises with engine speed | Strong from low speed | Strong from low speed |
| Mounting | Front of the engine, on brackets | On top of the engine, in place of the intake | On top of the engine, in place of the intake |
| Intercooling | Usually air-to-air or air-to-water ahead of the throttle body | Often an air-to-water core under the blower | Often an air-to-water core under the blower |
| Character | Smooth, builds to a strong top end | Instant low-end torque | Low-end torque with good efficiency |
Pros and cons of a centrifugal supercharger
- Pros: efficient at high RPM, keeps intake air temperatures manageable, mounts without replacing the intake manifold on many kits, and lets boost be changed with pulley sizes.
- Cons: less boost at low engine speed than a Roots or twin-screw unit, and the characteristic whine some owners love and others do not; see whining noise when accelerating.
Pulleys and boost
Boost on a centrifugal supercharger is set mainly by how fast it spins, which depends on the crank and supercharger pulley sizes. A larger crank pulley or a smaller supercharger pulley raises boost. Overdrive crank dampers do this from the crank side; see what does a harmonic balancer do? More boost needs the fuel system and engine calibration to match.
Centrifugal supercharger kits we carry
We carry East Coast Supercharging kits built around Paxton NOVI centrifugal head units, the NOVI 1200, 1500 and 2200 families, for the C5, C6 and C7 Corvette and the Camaro. ECS describes the NOVI 1500 as having self-contained oiling and quiet operation, and each kit listing states its head unit, intercooler and ECS’s quoted gains. Browse them on our centrifugal supercharger kits by platform page or by engine: LS1, LS3, LS7 and LT1. Read how much horsepower does a supercharger add? and supercharger vs turbo for the bigger picture.
More guides: supercharger belt slip · supercharger maintenance · twin-screw vs Roots · supercharger whine · how long a supercharger lasts · Paxton Novi 1200 vs 1500 vs 2200.
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