ow a lot of cars are with the engine of the T word, T word proved that it is a turbocharged engine. As we all know, turbo engine in the engine on the basis of the original increase the turbine device, in the operation, the turbine itself to run out of excess energy must be reasonably conducted out, which requires a device with the "energy and", which is the cold.

In the cooler will increase air resistance, so that the pressure of the air pressure drop, resulting in a decrease in the effect of the engine, the engine response to slow, but this effect is more important than the engine to enhance the role of the engine, it is insignificant.

Air cooling or water cooling?
To cool the air, nothing more than two kinds of methods. One is through the vehicle traveling by the head of the cold air to cool down, the other is the use of water cooling. The principle of the former and our household refrigerator, air conditioning radiator is the same, is to let the air through a root pipe, increase the contact area of the pipeline and the surrounding air, and then through the air around the cooling. Air cooling in the air above the engine.

Water cooling is just the opposite of air cooling. Is to put a cooler into the intake pipe, so that the hot air flow after the booster. While the cooler has a continuous flow of cooling water, so as to take the pressure of the air pressure.

The solid line shows the flow of air the dotted line, the flow of cooling water
First of all, the subject, when the air is compressed, the temperature will rise, this is a basic physical principle. What will the gas temperature rise after the pressure? This depends on the work of the turbocharger, the higher the speed, the higher the pressure, the higher the temperature rise, generally speaking, can rise 40-60 degrees Celsius, plus the original temperature of the air, the gas has been very hot.

High temperature gas on the engine effect mainly in two points: one is the volume of air, equivalent to the air sucked into the engine and fewer; and second more important, high temperature air for combustion engine particularly adverse, the power will reduce, emissions will go bad. Under the same conditions of combustion, the temperature of the air pressure increased by 10 degrees Celsius, and the engine power will be reduced by about 3% to 5%. This problem is very serious, and managed to increase the power will be high air temperature counteracted by in order to solve these problems, we need to put the pressurized air again cooling sending into the engine. And the part that takes on the important task is the medium cooler. In the middle of the cold is cool, in fact, the principle and structure of our household refrigerators and air conditioning radiator no difference.

Side effect: the engine response speed slow down the turbo lag becomes serious.
In general, the greater the middle cooler, the smaller the internal air flow loss and the higher the cooling efficiency, while the air flow in the internal cooling device, the longer the cooling effect is better. However, the cooler is like an increase in the volume of the intake duct, the compressed air generated by the booster must first fill the volume, and then to produce a boost effect. If you use the turbo boost, the direct performance is that the turbo lag is severe; even the mechanical pressure of the machine will cause the engine to slow down.

On the other hand, because the pressure air must flow through a variety of pipes, so the resistance increases, and the pressure will certainly be part of the pressure. However, this weakening is only after a very short period of time on the accelerator, because the air pressure is weakened after the pressure will be in the middle of the valve to enter the valve seal the space to build enough pressure, until the relief valve opens. As a result, the final performance is still slow, the engine response is slow, and the phenomenon of the turbo charge will become serious.

In order to make the turbo lag more obvious, but it can not be installed, so how to balance the cooling efficiency and pressure maintenance is the most difficult problem for engineers. One of the most fundamental approach is to reduce the volume of the entire intake pipe, reducing pipe resistance, shorten the pipeline, so we see the middle of the cooling device is often close to the engine, and not as far away from the engine cooling water tank. High pressure, large displacement of the engine due to the large intake of large, high temperature, often need a large and medium. Large cold we tend to see is placed on top of the engine, so you can through the engine compartment cover to open a port, use face crashed into the cold air cooling, this way in a lot of cars can see, such as the Impreza STI, minicoopers. On the top of the engine is the advantage of compact structure, pipeline is short, very suitable for car and car use. But this arrangement is too close to the engine, the engine will be affected by the heat of the engine.

MINICOOPERS and STI are in the Impreza cooling in the engine cover open
There is also a layout is cooler on the front part of the car under the net. This way to make full use of the face of the cold air cooling, but the pipeline is too long, more complex layout. The closer to the ground, by the possibility of failure is greater sand ground.

For these two cooling methods, it belongs to the external type of air cooling, suitable for large medium cooling device. And now the trend is a low pressure engine, do not need too much in the middle of the cold, but also in order to make the engine more compact, at present, many engines are using water cooling way, a cooler into the intake pipe, when the air is cooled, the structure is very compact.