Future of the power adder

The new Corvette ZR1 uses it. So does the BMW 3-series. Ford is working on Ecoboost, and, well, automakers such as Saab have always relied on it.

"It" happens to be forced induction, whereby power is added to small engine -- via a supercharger or turbocharger -- to help maintain a good mix of fuel economy and performance. It's the way of the future, at least as far as internal combustion engines are concerned and it's not necessarily the domain of high-end sports cars such as the 638-horsepower Corvette ZR1.

Just look at recent history. What do a pickup truck, a cute little two-place roadster and a tepid four-door compact sedan have in common?

The late, great Ford Lightning SVT, MazdaSpeed Miata and Dodge SRT4 couldn't have been any different in their approach to a common goal: to spice up life for performance enthusiasts with the help of a little pressurized air.

In simple terms, an engine's power is dictated by its displacement, or the amount of air it can breathe. Short of adding on a couple more cylinders, how can an engine have more displacement to make more power? Make it think it's bigger by adding a supercharger or turbocharger.

How does it work? "Boost" the pressure of the air available to the engine by, say, double (about 15 pounds per square inch) and a 5.4-liter engine will think it's twice as big: 10.8 liters. Since physics is involved, it's not quite that simple, but you get the general idea.

2004 MazdaSpeed Miata

Zero-60 mph: 6.7 seconds

Quarter mile: 15.2 seconds @ 92 mph

Cute, cuddly ... and, well, cute ... is how most people would describe the Miata (MX-5 for the 2005 model year), which is unfortunate since this little rear-drive wonder made for a great hot rod. In fact, Miatas are still usually the cars to beat at parking-lot autocross events. All that's needed is more power for a new attitude. By adding a small turbocharger to the largely stock 1.8-liter engine, horsepower increased by about 35 -- about 25 percent (to 178 from 142) -- which transformed the Miata into a car that was regularly quicker to 60 mph than our RX-8 test car. The reason is the Miata's light weight. It didn't take much horsepower to make it scoot. Add an upgraded suspension, bigger wheels and brakes and you had the MazdaSpeed Miata. And while you could have found an extra 35 horsepower by tearing apart the engine, reworking the cylinder head to flow more air and dropping a new camshaft into the mix, it was still just a 1.8-liter engine.

2000 Ford Lightning SVT

Zero-60 mph: 5.4 seconds

Quarter mile: 13.7 seconds @ 108 mph

Horsepower is just a number derived from the torque produced at a given engine speed. Torque, twisting force, just like your older brother proved when he nearly popped your wrist when you last arm-wrestled him, is what gets large and heavy objects such as Ford's F150 moving: Torque puts the snap in the gas pedal. The now-out-of-production Lightning SVT adds a small belt-driven supercharger to increase torque output of the 5.4-liter V-8 to some 440 pound-feet, more than 100 over stock. The factory horsepower rating of the 2000 Lightning used in this test is 360. The advantage of a supercharger over the turbocharger in this case is that the boost, and thus the extra torque, is instant because the supercharger is driven by a belt. A turbocharger is run by pressurized exhaust gas, which is unable to build immediate boost. That translates into a less throttle response and a somewhat lazy engine at lower speeds. At very high engine speeds and high levels of boost, a turbocharger is generally preferred, although there are exceptions to every rule. A supercharged 5.4-liter engine has been used in the Ford GT supercar (550 horsepower) as well as the Shelby GT500 Mustang.

2004 Dodge SRT-4

Zero-60 mph: 5.9 seconds

Quarter mile: 14.6 seconds @ 96 mph

On one hand, you might see a little old lady driving a Neon to the grocery store. Stuff in a turbocharged 2.4-liter four-cylinder with 235 horsepower and you had the SRT4, Chrysler's entry point into the SRT line of high-performance Crossfires, 300's, Dodge Chargers and V10-powered Ram trucks and Vipers. Matched to a five-speed manual transmission, Recaro seats that required some gymnastics to get in and out of, big sticky tires and better brakes, and the SRT-4 was a far cry from the base Neon. Without the turbocharger, most have considered it nothing more than a pretender with zero street credibility. If you've driven an SRT-4, you know that that's just not the case. Again, the extra torque helps push the car without having to keep the engine pegged at the redline. The modern extension of this is the Dodge-Caliber-based SRT-4 that makes 280 horsepower.

What else did these three seemingly unrelated vehicles have in common? They were all built by performance divisions of their parent company. Although the vehicles are no longer in production, rest assured there will be more supercharged and turbocharged wonders to "boost" the image of their base-vehicle counterparts and provide endless grins when the gas pedal is given a workout.