All of us see in games, and sometimes around us cars with turbo specs, don’t you feel like knowing what turbo means?? Lets see what lies behind that beautiful name and much more beautiful sound..
TURBOCHARGER is a type of forced induction system used in automobiles to increase their performance, horsepower I mean. That may sound rocket science, but believe me, the basic behind this is all but complex..
Lets go down to the basic of an internal combustion (I.C.) engine, it has an
intake valve
an exhaust valve
spark plug
piston
cylinder
camshaft
flywheel etc etc..
What happens is fuel and air mixture goes in, its ignited with the spark plug and bang!! down goes the piston and that through crankshaft and power train and transmission and the axle goes to the wheels. For more info on how I.C. engines work watch this
Now that we know what is the basic thing inside and engine, lets talk about human nature. It is basic human nature to take what he has to the next level, to be always unsatisfied with it, and to always look for a better option. So there was this unsatisfied swiss engineer Alfred Büchi who said in 1905, lets push some more gas in there!!
Engines are high pressure devices, the force of explosion produces a good amount of pressure that throws the piston out. But it’s a natural law that only a certain amount of air can be in a certain space, as is permitted by the atmospheric pressure. So accordingly only some specific amount of air can be inside the engine cylinder, due to that only a specific amount of fuel can be there because there is a definite amount of fuel air mixture to be fed. This automatically places a limit over the size of the explosion.
What turbo does is so simple yet so elegant, it simply sends air at a HIGHER PRESSURE so that more of it can go inside the cylinder so there will be a bigger explosion and more power!!
COMPONENTS OF A TURBOCHARGER
A basic turbocharger has two components, a turbine and a compressor. Turbo has one more distinguishing feature, it draws its energy from the exhaust gases. The outgoing exhaust gases move the turbo which moves the compressor as they are on a common shaft which then sends compressed air into the cylinder. This is the reason for the turbo lag, and this is what separates it from a supercharger.
I feels simple enough, doesn’t it?? But it’s a mighty more complex than that. Imagine you have a turbo car, you accelerate, the exhaust gases increase, so does the turbo speed, it again sends more high pressure air into the cylinder, which when burns sends more exhaust gases and so on the process grows exponentially until we get a blown engine. To fix this we have the concept of a wastegate. 2nd thing, imagine you have a turbo car and you accelerate, now there must be a threshold at which the compressor starts working, so when the threshold comes, there is a sudden push. So it would be very difficult to control such a beast on indian roads. These are some of the problems that come with this thing, not to mention others like air surge, cooling etc.. So, in short, you cant make one yourself!!
Turbos are seen all around us today, but it is a very complex technology, dealing with physics, chemistry, mechanics, aerodynamics etc..
Again, as I said, man is a very unsatisfied thing. Once you have a turbo, the obvious next thing is, lets put a hell load of them on!! So now we have multiple turbos. Twin turbo, sequential turbo and what not.
Its now time to discuss a related thing, intercoolers.
You must have seen it on one of the endeavours, or on those modified vehicles that have ugly stickers all over them. What is an intercooler?
It is a device used in between the two stages of a sequential turbo. When compressed air comes out of a turbo, its too hot for obvious reasons known to everyone who has read chemistry. When air is hot, its volume is less, so lesser air will be going to the next stage of turbo and hence to the engine which we don’t want.
An intercooler cools the air from one stage to the next. There is also an aftercooler that cools the air form the last turbo stage to the engine.
Now lets discuss that big thing with holes that pops out of the hoods of those mighty muscle cars that wheelie the moment you push the throttle, supercharger.
SUPERCHARGERS
Turbo is form of supercharger. Again, man is unsatisfied with everything. So he says why make the turbo work on exhaust? Lets give it its own power!
A supercharger, unlike a turbo, has its own power source, from the crankshaft. Rest it does all the same.
A well set turbo can add as much as 50% more power to the engine.
Just as a passing remark, the world’s biggest truck, caterpillar 797 series, has a 117000cc V-24 quad turbo 3400hp 12170 lb-ft diesel engine. It can carry 380 tonnes and still go at 67 kmph.
aK
Hey..great info..really interesting!
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