1. Tell me the difference between the 2 and why you think one is better then the other.



2. What is the cost advantage of building a kit with either or...
2a) what are long term cost for maintaining a S/C vs Turbo.

 

At the most basic level they're the same thing. The main difference is what drives the "blower" unit.

A supercharger is generally driven by a belt that is run off the engine itself.

A turbocharger is generally run off waste exhaust gases.

The benefit of the SC is that it's "always" on providing some power, and it requires less parts and plumbing overall. The drawback is it takes a little bit of hp to turn that belt.

The benefit of the Turbo is it's powered by "waste" so it's essentially "free" power. The drawbacks are that you might have some lag before it spools up (though nowadays there's many ways to mitigate that) and it requires a more complex setup and install.


For cars that came with a turbo, or some close relative did (ie an SC300 which shares a motor with the mk4 supra) a turbo kit is often fairly easy to cobble together from "stock" parts off the turbo version of the engine...which are often available cheap from folks upgrading their stock systems.

For cars that were never designed for a turbo system (say the SC400) then a supercharger is usually a bit easier.


In either case you ideally want a low compression engine and an ECU you can manage in some way.

The 2IS has neither of those and is a very poor candidate for forced induction. The couple of kits that exist (both superchargers) add relatively little power for a relatively high cost.