While the concept of turbo-changeovers is usually presented to address the forced-induction craving of most force-fed Pulsar drivers, there are other options available which are less-often considered.
This is where supercharging gets its fifteen minutes of fame.
There has been precedent for an E15ET Pulsar being ram-fed with a very non-standard and non-Nissan component; a Toyota ex-4AZGE engine supercharger. A supercharger, for those uninitiated, is a device used to feed high volumes of compressed air to an engine for efficient powerful combustion. Where this device differs is in its use of a belt drive run off the host engine’s drive belt gear as opposed to a turbine placed in the exhaust system.
A supercharger is a different animal to a turbo, and has its own advantages and disadvantages. The primary advantage of a supercharger is that throttle response is instant in a supercharged car. In a turbo effective compression is not achieved until exhaust form the engine has a cumulative effect on the turbo’s turbine, which in turn drives a commonly-shafted compressor. This spool-up process takes time. In a supercharger, however, as soon as engine revolutions increase the supercharger compressor responds directly under the control of a belt driven by the revolution of the engine. This means immediate and proportionate power delivery – no lag and normally-aspirated drivability is achievable.
Another benefit is that no matter how efficient a turbocharger the turbine in the exhaust train will always present a restriction to smooth exhaust flow. In a supercharged car the exhaust system is clear, allowing the use of a set of nice extractors and a straight-thru exhaust from the cylinder head to the exhaust tip.
Inversely, a supercharger also has a downfall – which, ironically, springs from its greatest benefit. That is, by utilising a direct engine drive belt, a supercharger places an additional load upon an engine to drive another component in addition to the crank, camshaft, drivetrain, etc. etc. A turbo avoids causing this drag by harnessing its driving power from spent exhaust. On the whole, however, a supercharger’s benefit from high-flowing and pressurising inlet air outweighs its cost on engine drag…naturally, or else no one you’d use them, right?
The choice between turbo and supercharger seems to be one of personal preference in terms of driving characteristics rather than one which can be summarised by a line such as ‘choose turbo ’cause it’s best’ or ‘vote-one supercharger.’ Having said that, I know of many turboed N12 Pulsars, yet only one supercharged example – and that’s a work-in-progress. You can contact the owner, Stu, for more details.
* Just a thought; does it then become an E15ES engine?