Huw Evans
February 1, 2009
Photos By: Keith Keplinger

If you're looking to make sizeable gains in horsepower on your Mustang or Ford vehicle, one of the best things you can do is invest in a supercharging system.

Although the entry price may initially seem steeper compared to some other bolt-on upgrades, the long-term benefits, especially on street-bound vehicles, often far outweigh the entry price. Since the early '90s, aftermarket supercharger kits have proved wildly popular on Ford engines, due in part to the introduction of sequential fuel injection on the 302 V-8, first introduced for 1986. But if you go back into the archives, you'll discover that supercharging internal combustion engines is nothing new, and in fact dates back to the '20s.

On Ford vehicles, the first recognized supercharger application was developed by Robert Paxton-McCulloch for use on Flathead Ford V-8s, the first examples of which were introduced in 1937. Prior to the outbreak of World War II, Paxton-McCulloch managed to sell 5,000 of its supercharger kits, which gave the already relatively fast Ford V-8s an extra shot of oats. During World War II, supercharging really came into its own, particularly in aviation circles. Because an engine in many respects works like a giant air pump, the greater the volume of air you can force into it, the more power you can make. At higher altitudes, piston engines suffer from a loss in power and throttle response due to the reduction in air density. Through the use of superchargers to increase the air volume entering the engine via a crankshaft-driven turbine, the power loss problem was effectively eliminated.

In the post-war years, the concept of a relatively low-cost, self-contained supercharger, designed for quiet operation and optimized for low-end boost in passenger cars, really took off. By the early '50s McCulloch had introduced a ball-drive supercharger that used an internal planetary gear system and incorporated a 4.4:1 step-up ratio from the input shaft at the front of the supercharger to the impeller. A mechanical oil pump and reservoir provided lubrication for the drive mechanism (using transmission fluid). By the mid-'50s, Ford and Studebaker were offering supercharged engines on passenger cars, utilizing the Paxton-McCulloch on offerings such as the 312 F-code Ford Y-block V-8s fitted to select Thunderbirds and lightweight sedans. Supercharger development continued through the '50s and '60s, but fell from favor a decade later as emissions requirements and fuel economy concerns began to bite.

However, supercharging began to enjoy a renaissance in the late '80s that continues to this writing via electronic, sequential fuel injection. Engineers discovered that by separating the air and fuel paths in an internal combustion engine, they were able to more precisely control the air/fuel ratio and delivery, which combined with increasingly advanced electronic engine controls, enabled power, emissions, and fuel economy to work more or less in harmony. It also proved the perfect foundation for a new generation of superchargers. By increasing the airflow into the engine, using advanced controls to retard spark timing, and compensating for the increased air by a more aggressive fuel system, with higher flow rates, bigger fuel pumps, and larger injections, it was possible to double the horsepower of an electronically port-injected engine by bolting on a supercharger kit. An added bonus was that by introducing adjustable fuel pressure regulators and later fuel management units, these new supercharger kits were fully emissions legal. The supercharger phenomena has reached new heights today, thanks in part to the popularity of the 5.0L Ford Mustang. A huge range of supercharger applications is available from a wide variety of different manufacturers, which is why we put this guide together.