If you've tried the bolt-on big-power makers like a solid roller cam with monster lift and you're tired of an engine that won't idle and only makes power at high rpm, then listen up. A forced-induction arrangement might be just what you need. Superchargers are mechanically driven while a turbo-charger is exhaust driven, but both do the same thing: force more air/fuel mixture into the combustion chamber. This makes for more power in a big way.
Our atmospheric pressure is approximately 14 psi, and it is this pressure that feeds our normally-aspirated engine. If we use a supercharger producing one atmosphere of boost, then the blower is adding 14 psi of induction pressure at the intake. That's a lot of boost, and a more streetable figure would be one half an atmosphere or about 7 psi. If we take a 300ci engine and add a blower running at 7 psi, then we have an engine functioning about the same as one with 450 ci normally aspirated. In practice, output would be somewhat less because blowers are not 100 percent efficient. Using one atmosphere of boost on a 300ci mill is like having almost 600 cubes underhood. It's easy to understand why forced induction is so popular because a small addition in size and weight means a huge power addition.
Turbochargers produce boost just like a mechanically-driven blower but usually take longer to respond to the throttle and are a little more complicated to install. They do offer the advantage of having no parasitic power loss because they run on exhaust gases that are already on their way out of the engine.
Nitrous oxide is easy to install and doesn't require a mechanical device to push the gas into the engine because it's already under high pressure inside the bottle. Introduced into the fuel and air slipstream, it has the same function as a blower in that it adds more oxygen to the combustion chamber. As the nitrous is introduced, extra gasoline is added simultaneously. Let's take a look at some of the forced-induction products out there. There are many that would make a nice performance upgrade for your classic Ford.