Dyno Tuning Melbourne - Superchargers

The difference between centrifugal and positive displacement blowers, is that basically a centrifugal is similar to a turbo charger. It doesn't rely on exhaust to push it around, but it relies on the engine RPM to spin it up.

The more you spin it up, the more boost you get.

Generally you find a centrifugal supercharger mounted off the side of an engine. They're generally made to be mounted on the side of engines, away from the top of the manifold. One of the advantages to a centrifugal blower (over a positive displacement blower), is that you can mount an intercooler fairly easily, so you can get more performance out of it.

The other advantage is that generally they are a lot quieter than a positive displacement blower. And, placement of them is fairly easy. You can place them above, below, in front, behind. So, there are many places they can go, so long as they line up with whatever is driving them.

Positive displacement superchargers generally have to go on top of the motor, or at least on top of the intake manifold. So, fitting an intercooler can still be done, but it is often more difficult than when fitting an intercooler to a centrifugal supercharger. There is a lot more engineering and pipework needed to fit up an intercooler to this type of supercharger.

The main positive for a positive displacement supercharger is that the minute you crack the throttle you have boost, where with a centrifugal one, often you have to build up the revs before you start seeing boost, and you often won't see boost straight away.

There are two main types of positive displacement superchargers. There is the roots type, and the screw type. Generally you find the roots superchargers to be more noisy, and less efficient unless you put some type of intercooler on it.

The screw type, positive displacement, they are very good, but they are generally a long unit, so room has to be allocated for it.