The intake type exhaust pipe usually means that the entire exhaust process can be shortened, and even purification devices such as car mufflers can be removed. It is hoped that after modifying the middle and front ends of the exhaust, the car will accelerate faster, the power will become sufficient, and the dynamic auditory effect during engine operation will be improved, avoiding street explosions.
If you want to change the exhaust, I have some suggestions here. Firstly, it is necessary to determine one's psychological expectations and budget. What do you want, how much do you want to spend, how much more is acceptable, and so on. Just want to hear a simple voice, or want to change the appearance, or compete, or something.
2. Learn more about product information,
Experience various aspects of the product, as well as the aspects you are concerned about, such as sound, appearance, and so on.
3. Try to choose exhausts with valves and brands.
4. Don't choose the beast like roar of hundreds of dollars.
5. Please do not let your exhaust gas affect others' rest.
What is the structure of the entire exhaust pipe? What is the principle behind the change in exhaust pipe sound? And why does the master say that the improved exhaust will lose low torque?
1. The composition of automobile exhaust pipes.
It is used to collect exhaust gas, which is the exhaust pipe of a car. Its main components include the exhaust manifold, exhaust pipe, exhaust temperature sensor, catalytic converter, car muffler, and exhaust pipe.
1.1 Exhaust pipe.
The position connected to the exhaust ports of each cylinder of the engine. The main function of this system is to collect exhaust gas passing through the cylinder head exhaust port and transfer it to the exhaust manifold, which is equivalent to the beginning of inhalation and exhalation. It is necessary to minimize the resistance to exhaust during this process, reduce the mutual influence between cylinders, and ensure smooth exhaust emissions. (Some people have mentioned variable intake technology before, but in fact, this is mainly done here. By controlling the opening and closing of the valves in the air chamber and adjusting the length of the intake manifold, at high speeds, the length of the intake manifold can be adjusted according to the engine's operating conditions, the amplitude of stepping on the accelerator, and the engine's torque requirements, making intake smoother, torque, etc.)
1.2 Exhaust corrugated hose.
Also known as exhaust hose, it is positioned in three parts: three-way catalytic converter, automobile muffler equipment, and engine exhaust manifold. The connection method is flexible connection. Its function is to reduce vibration, provide buffering, facilitate installation, extend usage time, reduce noise, etc.
1.3 Three way catalytic converter.
After being placed in the car exhaust pipe, its function is to purify the exhaust gas. The working principle of a three-way catalyst is to convert various harmful gases generated by insufficient combustion, such as CO, HC, NOX, etc., into water, carbon dioxide, nitrogen, etc., and discharge them into the air.
1.4 Car muffler.
Its function is to reduce engine noise. The noise reduction device used in cars has two pipes of different lengths, and the difference between the two is exactly equal to half of the wavelength of the exhaust sound wave. This way, the sound waves will interfere when stacked, reducing noise or canceling each other out. For example, the original car's exhaust pipe may have an additional muffler than the sports exhaust pipe you want to add. When the exhaust gas is discharged to the muffler position, the original car's exhaust will have a swirling process, buffering the exhaust emissions and affecting the sound wave. And adopt a straight through exhaust system, with exhaust gas flowing directly towards the exhaust end. That's the difference in the middle part. So there was another modification plan, which was to cut off the muffler in the middle of the original car and weld a section of the exhaust pipe. However, this was a test of welding technology, and if there was even a slight air leak, it would not be as good as the original car's exhaust.
1.5 If the exhaust pipe tail throat has already occurred.
Put it into the original exhaust tail. Its function has two aspects: firstly, it can effectively convert the sound of the exhaust tailpipe into a softer one, reducing noise; The second is for decorative purposes. For example, changing the tail throat from two exits of 03 to four exits.
2. Design principles for exhaust system renovation.
Reducing the exhaust back pressure of the engine exhaust pipe is the main principle of exhaust system modification. Exhaust gas backpressure refers to the situation where the force of the exhaust pulse is obstructed by the pressure from the exhaust pipe during normal exhaust of a car's engine, resulting in poor exhaust flow. To reduce exhaust back pressure, it is necessary to make the engine alternate between intake and exhaust as smoothly as possible, increasing the time it takes to enter the exhaust valve. Generally speaking, modification refers to changing the structure of a car muffler to increase the airflow area during engine exhaust, making the exhaust smoother.
3. Why do we say low twist?
In terms of exhaust system modification, it usually starts from the middle section. The key to improving the drum to tail design lies in the tube design. There are two forms of pipe design: "thin" and "short thick". The former refers to changing only the material of the exhaust pipe body when the bending shape of the exhaust pipe remains unchanged. The advantage of this utility model is that it can be quickly discharged in the high-pressure exhaust pipe, and the engine is significantly improved under low and medium torque, making it suitable for daily urban driving. Short and coarse modification refers to reducing the length of the pipe body and increasing the diameter of the pipe. The advantage of this modification method is that it is denser when the engine speed is high, resulting in a greater increase in engine horsepower and smoother exhaust; The disadvantage of this modification method is that the exhaust pipe is low and the exhaust gas flow rate is slow at low to medium speeds. The mixed gas is forcibly discharged before it is completely burned in the cylinder, resulting in slightly lower torque of the engine at medium and low speeds, known as low loss torque.
4. Regarding the modification of ternary catalysis.
A three-way catalyst is an essential environmental protection device. But it slows down the flow rate of exhaust gas and generates a certain resistance effect, which will interfere with the efficiency of exhaust, so some modifications are needed. The general method of replacement is to directly remove or replace the existing catalytic converter to improve exhaust efficiency. But these methods cannot convert exhaust gas into exhaust gas, which may result in engine emissions not meeting standards during testing.
5. The straight and back pressure types of exhaust tailpipes.
The exhaust modification involves the middle part of the vehicle, the oil outlet of the engine, the tail injection section, and the catalytic converter silencing part. In general, the modification of the exhaust pipe tailpipe is divided into two types: back pressure and straight exhaust. The modification method should be selected according to the characteristics of the vehicle model and itself. In the backpressure type structure, there are a large number of artificial baffles in the tail throat, which increase the pressure of the cylinder and increase the combustion ratio of the engine to improve its exhaust pressure. The characteristics of backpressure are high engine torque and loud exhaust pipe noise. Direct exhaust type, with a large inner diameter of the tail throat and a smooth and shiny pipe wall, can ensure smooth exhaust. Due to the high engine speed and relatively high power, the corresponding sound is also relatively loud. In addition, the difference between backpressure and direct discharge sound waves is generally that the sound produced by backpressure is lower and richer. The sound of going straight is louder and higher.
