What is Turbocharging?
So most of you would have seen the term “turbocharged”, “Turbo” or Turbodiesel on and around cars but what does it mean? Well to understand the turbo’s purpose you first have to understand the basic concept on how an engine works. Most modern combustion engines work on a four-stroke cycle, Suck, Squeeze, Bang and blow. First, it sucks in the air and fuel mixture, then it compresses it then ignites it (this explosion in the cylinder forces the piston down creating the power) then expels it out the exhaust. The more air and fuel you can put in the cylinder means greater the explosion which equals more power.
So where does the turbo come into play?
Well understanding that an engine requires air to produce power and that the more of it means more power. The turbo’s job is to force more air into the combustion chamber although not complicated a turbo does it in a clever way. A Turbo uses the exhaust gasses leaving the engine to spin a turbine wheel which is connected via a shaft to the compressor wheel as in the image above. The great thing about this is that it uses the exhaust gasses that would usually just exit the car, so no wasted energy. So to sum up the exhaust gasses exiting the engine spin the turbine which in turn spins up the compressor forcing more air into the engine.
Turbocharging is not a new concept and has actually been around for quite a while now. Back in the ’80s, it was fairly popular but it was mainly used on performance cars and the big problem then was “Turbo Lag”. Turbo lag is the difference in time between when you put your foot down and the turbo kicking in. This happens because the turbo uses the exhaust to spin up and provide boost, if there are not sufficient gasses the turbo won’t be spinning fast enough to provide enough boost. This was quite noticeable on high boost cars like the Ferrari F40.
Today though turbos serve mostly an efficiency role allowing manufactures to downscale on engine sizes without sacrificing performance. Let’s take the Ford Fiesta as an example in 2009 the Titanium model was powered by a naturally aspirated 1.6l petrol with average outputs of 88kw and 149nm of torque. The new Fiesta equipped with the award-winning 1.0l EcoBoost engine has 92kw and 170nm showing significant performance increase. The other upside with downsizing is a notable decrease in fuel consumption, using the same engines above, the claimed figures where 5.9l/100km and 4.3l/100km respectively.
With the growing environmental concern more and more manufacturers are going the turbocharged route and soon all cars will either be powered by small turbo engines or fully electric or a combination of the two.