Looking for a boost?

2005 Dodge SRT-4 (Photo: DaimlerChrysler Canada)

One of the oldest and most common ways to make a little engine do big things is to use boost from a turbocharger or supercharger. Why bother? Why not use a big V8 instead? Well....V8's need a lot of room to fit. You'll never get a V8 under the hood of a WRX or a small Volkswagen. No, that's like trying to park a Hummer in a grocery cart return- both fun ideas but unlikely to work. To fit a V8, the car itself needs to be larger- and we all know that little cars with big power are huge fun.

Boost involves forcing the air and fuel mixture your engine feeds off of into the combustion chamber under pressure, allowing more of the mixture to be forced into the same space. In doing so, a four cylinder engine can perform like a six cylinder, a six cylinder like an 8 cylinder, and so on. So what does it mean when you see a car wearing a "Turbo" badge?

Ill tell you, and in doing so, free you from the masses of adults who drive turbocharged cars and don't know how they work.

"Dad, how does the turbo work?"
"Well, it kind of...uh...go ask your mother."
Sound familiar?

A turbocharger consists of a turbine placed in your engines exhaust system, close to the engine where the exhaust gasses are still expanding

2005 Dodge SRT-4 (Photo: DaimlerChrysler Canada)

and very hot. The exhaust gasses are forced through this turbine, causing it to spin at a very high rate of speed. This turbine is attached to another separate turbine which sits on the other side of the turbocharger. The two are sealed off from one another. The second rotating turbine spins at the same speed as the turbine in the exhaust system, but acts as a pump to force extra air into the engines intake. The end result: the more you open the throttle, the more exhaust gas is produced. This drives the pump faster, forcing more air in, and creating more power. If it sounds like a turbo provides a quickly building surge of power, you're exactly right.

"But the mileage!" you say. "A car with a quickly building snap of power almost certainly uses more fuel than a car without one." Well, the nice thing about turbocharged engines is that you can just cruise around gently- only using about as much gas as a normal four banger. Hit the throttle and the turbo comes on, making a high pitched whine as it "spools" to life and almost instantly sends the car rocketing along

The Dodge SRT-4 is a good example. Its 2.4 liter turbo engine creates 230 horsepower. That's more horsepower than two Kia Rio's, under the hood

2005 Dodge SRT-4 (Photo: DaimlerChrysler Canada)

of a Neon! (It isn't really a Neon...and don't ever call it one to its owner, because if you do, He will show up at your place at 3 am to autograph your driveway with his tires.)

I spent a little bit of time driving one of these monsters the other day. Pin the accelerator, wait a split second for the turbo to come on, and it feels like you've been rear-ended by a speeding dump truck. It's a lightning fast little car, and I can't think of anything faster for the money. It's fairly economical if you never use the turbo, which really comes down to a matter of self-control (good luck). The SRT-4 starts under $29,000, while the Jekyll and Hyde personality makes it worth every penny.