Have you ever wondered how does an F1 Engine generate so much power? Be it a road car or a formula 1 car the basics of the working of an engine are the same. So, let’s see how do engines generate that power. Also, while talking about engines especially in a context of racing cars it’s better to discuss the turbocharger simultaneously.
Every now and then you must be hearing the word turbo, especially if you are a big fan of race cars. So, what do they actually mean by the word Turbo? What they are actually referring to is the Turbocharger. So, let’s see how it works.
Before I get into the working of a turbocharger it is essential to know certain basics about working with an engine and the reasons as to why turbocharger is needed to produce more boost.
The Engine consists of :
- 1.Intake valve
- 2.Exhaust valve
- .Spark Plug
- 4.Cam Shaft
- 5.Engine Cylinder
- 8.Fuel Injectors
- 9.Timing belt
So, how do these components interact with each other?
Engine Working Steps:
1. At first, air is drawn into the engine through the intake manifold by the downward movement of the piston in the engine cylinder which creates a negative pressure and draws in air, this air is then fed into the engine cylinder through the intake valve. The intake manifold also has a throttle valve, so what basically happens when you press the throttle is that more air is fed into the engine cylinder.
2.Next, Fuel is injected into the engine cylinder by the fuel injectors. In old cars this job was done by the carburettors which fed fuel mixed with air into the cylinder but these days the air is directly fed into the engine cylinder and the fuel is then sprayed on by the injectors bypassing the role of carburettors.
3.Once we have the air-fuel mixture in the engine cylinder, the piston again moves up and this compresses the air inside the cylinder.
4. Now, a spark is generated by the spark plug and this ignites the highly compressed air-fuel mixture leading to the power stroke of the piston.
5. The piston inturn is connected to a crankshaft which due to the power stroke of the piston starts rotating and this rotation is what is known as “torque”. This rotatory force is then transmitted via a flywheel and clutch mechanism to the transmission or the gearbox.
6. According to the gear selected the rotatory force is then transmitted to the driveshaft.
7. Depending on the configuration of the car, say it’s a 2 wheel rear drive; the rotatory force generated will be transmitted by the driveshaft to the rear differential which is connected to the wheels by the axle. If on the other hand we have 4 wheel drives the rotatory force coming out of the transmission will be transferred by both the rear and the front driveshaft to the rear and the front differential, thus giving all four wheels the rotatory power initially generated in the engine.
8. Coming back to the engine cylinder the gases generated during the power stroke of the piston is now taken up by the exhaust valve and these gases are then released via the exhaust into the atmosphere.
So, I hope now you have an idea as to how an engine generates power and how this power is subsequently converted into rotatory motion and then its transmission to the wheels.
At this moment, we are in an ideal situation to discuss the turbocharger.
Why do we need a Turbocharger? A turbocharger is a device which uses the exhaust gas to draw in more air and then compresses it before feeding it into the engine. So, as more of compressed air is fed into the engine there is more of oxygen which leads to more combustion and in turn a greater explosion which corresponds to a stronger power stroke and thus more torque.
Turbo Charger Components:
- Turbine Wheel
1. As the exhaust gases exit the car they are fed into the turbocharger assembly.
2. The high speed of the exiting gases inturn rotates the turbine wheel, which creates a negative pressure.
3. This negative pressure inturn leads to intake of more air.
4. The air is then fed into the compressor where its converted into a high-pressure low-velocity air stream.
5. This highly compressed air cannot be directly fed into the engine as it has a very high temperature and so has less volume.
6. The air is then passed through an intercooler which cools down the air and this air is then fed via the intake manifold into the engine.
7. Thus, more of highly compressed air is supplied to the engine and as a result, there is better combustion leading to increase in power.
These were the basics of the working of a turbocharger. Now, let’s discuss wastegate.
A wastegate is a clever mechanism which is used in a turbocharger to prevent damage to the engine components. If there is no wastegate, as more of the exhaust gases rotate the turbine there will be an exponential increase in the air fed into the engine and this can damage the engine components. So, the wastegate is set at a particular pressure, say 8 psi, so when the air coming in exceeds 8 psi the exhaust gases are directed through this wastegate bypassing the turbine wheel thus limiting the air pressure to 8 psi.
Being a racing fan or a fan of sports cars you must definitely have heard of the word “Turbo Lag”. So, what is it?
Turbo lag in simple terms is the time difference between pressing the throttle and feeling the torque in case of a turbocharged engine. That is as soon as you press the throttle you don’t get the rush of torque immediately instead there’s a time lag after which there is a sudden increase in power delivery.
The reason as to why there is turbo lag in a turbocharged engine is that when the driver goes off throttle the amount of exhaust gases generated decrease and so there is a decrease in the turbine spin thus less of air is taken in by the turbocharger. So, when the driver again gets on the throttle there is a time lag which basically is the time needed to generate sufficient amount of exhaust gas to spin the turbine at a higher velocity and deliver the same level of compressed air into the engine cylinder.
How can we overcome Turbo lag? There are some very innovative mechanisms to overcome turbo lag but that’s something which will be discussed in a separate article. Another term which you may have frequently come across is the “Supercharger”. Ever wondered as to what is the difference between a supercharger and a turbocharger?
A supercharger is connected directly to the crankshaft and as the crankshaft rotates the turbine wheel of supercharger rotates drawing in air and the processes therein are similar to a turbocharger. So, the basic difference is that a supercharger takes power to spin the turbine from the crankshaft while a turbocharger uses exhaust gases to do the same.
That sums up Engine and Turbocharger. Hope you had fun reading it. If you have questions feel free to ask in the comments.