Car exhaust system modification requires professional parts manufacturers
Car exhaust system modification requires professional parts manufacturers
SNW today talks in depth about what automotive systems can bring to automotive power? For the auto parts industry, all auto parts are not developed and manufactured by car brands. Each accessory system is developed and produced by the manufacturer for the brand manufacturer. Therefore, SNW is a R&D and manufacturer of automobile exhaust systems, providing high-quality services. Performance Automotive Dynamics offers comprehensive solutions.
When it comes to power system modifications, exhaust modifications are inevitable. By replacing and upgrading the exhaust system of the vehicle with a higher performance, the engine can be sucked more smoothly, thereby improving the power performance. This can be said to be one of the simplest and most direct ways. Regarding the domestic modification status, exhaust modification is very common. The most important thing is that modified exhaust can not only improve performance, but also a better-looking exhaust and sound can attract the attention of passers-by, or a car. The louder the exhaust sound, the easier it is for others to think that this is a modified car. Therefore, when it comes to exhaust modification players, perhaps what they pay more attention to is not how much this set of exhaust can improve the vehicle, but how much attention it can attract from passers-by.
In fact, this is incorrect. First of all, the purpose of modification is incorrect. In addition, there are many common misunderstandings among non-DIY modification players. When it comes to exhaust knowledge, I think we have to start with the misunderstandings.
1. The original exhaust performance is poor and must be modified!
Before a vehicle leaves the factory, the exhaust system must be repeatedly tested by the manufacturer. It is a product designed and produced based on multi-dimensional considerations such as the vehicle's power performance, environmental protection, fuel economy, cost, laws and regulations, etc. Therefore, the original exhaust is limited by various reasons, and its performance is balanced. It cannot be said to be the most suitable for a certain car, but its performance is definitely not bad. A set of original exhaust is more reasonable for all aspects of the vehicle, especially in small-displacement models. Small-displacement models have a common feature, the exhaust is not smooth, and this design is optimized In order to overcome the inherent low-torque characteristics of small-displacement engines, appropriate back-pressure design causes the exhaust to produce a resonance effect, which can make the exhaust efficiency of the vehicle engine better at medium and low speeds. It can be seen from this that the original exhaust is developed and produced taking into account the car needs of most people, that is, the working conditions of vehicle driving on urban roads.
Why do we say that the original exhaust performance is not bad? Because we must remember one sentence: the car manufacturer considers the needs of most consumers, not the needs of a small group of people. In high-performance models, the original exhaust design will be completely different from that of urban economy cars. For example, an exhaust system with lower back pressure, various exhaust manifold designs, and large-diameter pipes will be used. Road, etc. to increase the output power of the engine. Once again, the exhaust performance of the original car is not bad! It’s just that the positioning and needs of your car are different or have changed. The original exhaust design cannot satisfy you in order to compromise the mid-low speed!
2. The louder the noise, the better it sounds, the more horsepower it has, and the better the car is.
Although this concept does not exist in the eyes of people who know cars, it is inevitable that some people will think so, so let me talk about it. First of all, this is not true. I can easily make the exhaust sound of any car sound better and louder. If I am in a good mood, I can even make it for free. There is one part in the entire exhaust system that is responsible for muffling sound, which is the muffler. There are two mufflers in an ordinary exhaust system, which are respectively distributed in the tail section and the middle section of the exhaust. As long as any one of the mufflers is removed, the exhaust sound will become louder. Is it not loud enough? Then remove both, and you are satisfied. Yet? As for the better sound? It's also very simple. You don't need to spend money to replace the exhaust. You only need to give me a can and I can make you have dense sound. Do you believe it? But if you do this, you will increase unnecessary fuel consumption, lose low torque and even lose power. So horsepower doesn't depend on exhaust sound.
3. Only changing the exhaust tail section can significantly improve the power output.
I don’t know which unscrupulous exhaust manufacturer’s marketing ploy this sentence comes from. But I have seen more than one car do this. It can be said that there are many cars modified in this way. I haven't really tested whether changing only the tail section can improve it, so I can only say that even if there is an improvement, it can be ignored, and there will definitely not be a significant improvement. So what if the entire exhaust section is modified at the same time? It stands to reason that the entire exhaust section has been replaced with a high-performance exhaust. Logically speaking, the smoothness of the exhaust should be greatly improved. Strictly speaking, this view is wrong. Exhaust modification must be accompanied by intake modification. These two things complement each other. why would you say so? It’s very simple. Think of a car as a person. The air intake and exhaust represent the person’s breathing. If this person inhales less air but exhales more air, what does it look like? I don’t need to say more. I believe everyone can imagine it. If it doesn’t work, you can try it yourself. There is a saying that "there is air going out and air entering." So I can definitely say that it is useless to just change the exhaust. Regardless of the entire section or the head section and the tail section, it must match the air intake system. (Don’t believe the claim on X Bao that the S drum can increase power without losing low torque. Now that horsepower machines have become popular, any modification shop can confirm that this is a fallacy!!)
4. The thicker the exhaust pipe diameter, the better, and the lower the exhaust back pressure, the better.
The exhaust pipe diameters of all performance cars and even supercars are much thicker than those of ordinary family cars, which leads some people to mistakenly believe that the thicker the exhaust pipe diameter, the better, and the exhaust will be smoother, which sounds like there is nothing wrong with it. In fact, anyone who has a certain understanding of the exhaust system will know that the most important factor restricting exhaust is back pressure. The level of exhaust back pressure is directly related to the maximum power output and power output characteristics of the engine. Therefore, no matter how thick the exhaust is, the extra pipe diameter is unused and unnecessary. It will only add unnecessary weight to the vehicle and take up more space. (Generally, the exhaust pipe diameter of a 2.0 engine is preferably 50mm-80mm).
But low back pressure is not a good thing. For Honda S2000, it goes without saying. For those who don’t understand, you only need to understand the output characteristics of this car. This is a high-speed car. Engine performance car. Let me drive this car. Since I know the torque characteristics of this car very well and I know the power point of this car, I can drive this car very smoothly and briskly. But what would happen if my dad drove this car? Due to the low exhaust back pressure, this car has a lack of low-end torque (powerless at low revs). In addition, my dad has to shift gears at about 2000 rpm. He will feel that this car is very difficult to drive and does not drive at all. You would think this is a performance car. (Although I don’t have an S2000, my dad scolded me after driving my BRZ...the reason is the same).
The power output characteristics of a vehicle are related to many factors, and exhaust is only one of them. The lower the exhaust back pressure, the smoother the exhaust, which makes the exhaust gas flow rate in the pipe become very slow at low speeds. This is also the reason why high-speed engines lack low torque (the exhaust is not smooth at low speeds and smooth at high speeds, so the engine The focus is on high speed) so the modified exhaust should be selected according to your own car needs and environment.
5. Exhaust sound.
I believe that half of the people reading this article don’t understand where the exhaust sound comes from? Some people may think it comes from the engine, some people may think it comes from the gas itself, and some people have even never considered this issue at all. In fact, the sound of the exhaust comes from the vibration of the gas. Another function of the exhaust pipe is shock absorption. If it is unobstructed, the shock-absorbing effect will be weakened, and the sound will be louder.
Okay, the misunderstandings I can think of are the above five points. If you have any questions about exhaust, please feel free to add them. Now let’s talk formally about the car’s exhaust system.
How does the exhaust system improve performance?
General modification technicians will tell you that the smoother the exhaust, the better the power will be. This is the only thing that many junior modification players and technicians can say.
Then more advanced technicians will say that it is to make the exhaust gas discharged from the cylinder more unobstructed. If the exhaust gas is unobstructed and the exhaust gas is discharged cleaner, the combustion will be better and the power will be stronger. (There seems to be no difference....)
If you are still not satisfied or even confused, this is normal, because this is just a one-sided feeling, not a scientific explanation. There are several methods for car exhaust modification:
- To change the muffler to a smaller size or remove the muffler, usually the middle exhaust muffler is removed so that the exhaust becomes a straight pipe.
- Change the muffler structure. The original factory uses a pipe to guide the exhaust gas into the complex metal asbestos noise reduction and shock-absorbing material, fully muffle it, and then export it from the other end, so the original car exhaust is very quiet. Modified exhaust generally uses a pipe to go straight through, with many holes punched in the pipe wall. The outside of the holes is the silencer material, which only performs indirect partial silencer.
C. Increase the pipe diameter.
D. Remove the three yuan. The ternary element is a component that filters exhaust gas. Although this component can greatly reduce harmful gases in the exhaust, it also greatly hinders the exhaust. Although this is the most efficient method, it is not environmentally friendly...
These modification methods are undoubtedly to make the exhaust more unobstructed, that is, to reduce the exhaust back pressure. What impact will the reduction of back pressure have on the exhaust? First of all, taking a four-stroke engine as an example, it is divided into four steps: intake, compression, ignition and exhaust, that is, four strokes. Driven by the camshaft, the intake valve is first opened, and fresh gas is sucked into the cylinder from the intake valve as the cylinder moves downward. Then the intake valve is closed, compression and ignition are started, and finally the exhaust valve is opened, the cylinder moves upward, and the exhaust gas is discharged from the exhaust valve, thus completing a cycle. Then the intake valve opens again, starting the next cycle, and repeats.
Back to the exhaust, after the exhaust modification, the exhaust is smoother, which means the exhaust back pressure is reduced. The exhaust back pressure is small, and the engine exhaust gas can be more easily forced into the exhaust channel, while the valve overlap effect To reduce the pressure, less air will be pressed into the intake duct during the overlap process. There is no need to understand the concept of valve overlap here. Just remember what was said before. At this time, the intake air will become less at low speeds, and the exhaust pipe will The exhaust gas flow rate will slow down and the exhaust will not be smooth. But once the speed increases, earth-shaking changes will occur. The valve overlap effect will become stronger. Not only will more air be forced into the intake pipe, but the flow rate of the exhaust gas in the exhaust pipe will also become faster and smoother. The most direct feeling is power. Big improvement!
Exhaust modification is not 100% beneficial to performance. Again, it depends on the crowd. Modifying the exhaust will more or less lose low torque. For me, low torque is useless, which is the fleeting low speed. moment, but for a family car, it may be essential. If the exhaust is too smooth, it will be more difficult to drive in the city, and the more traffic jams, the more uncomfortable it will be. This is one of the reasons why supercars are very difficult to drive on urban roads. In this regard, what I want to say is that if you are going to modify the exhaust, you should understand the above conclusions and principles!
How to modify the exhaust?
Pursuing sound: The relationship between exhaust modification and sound is generally that the closer to the engine, the greater the change in sound and the greater the increase in volume. Based on my many years of experience, in addition to the impact of the rear silencer on the sound, generally speaking, replacing only the rear exhaust will increase the exhaust volume by three times compared to the original car. Although it looks like 3 times, the actual effect is not as obvious as you think. After replacing the middle and rear exhaust sections, the sound can be increased by about 2 times, which is about 6 times that of the original one. At this time, such a sound is enough for ordinary people, and it is very likely that when you drive your car back to the community at night, you will be hated. If you go one step further, it is to remove the three-way catalytic converter (I personally recommend not to do this unless you go to the track), or better yet, replace it with an expensive competitive three-way catalytic converter. Then your volume will increase by another 2-3 times. , reaching a volume more than 10 times that of the original car. At this time, you can already "hear the sound of the car before you see it". You can know that you are coming from a hundred meters away... This is just me Personal advice, so for those car owners who ask me how to make the sound better but are reluctant to spend money, stop asking.
Performance issues: The impact of exhaust back pressure on vehicle power output characteristics has been mentioned above. One thing to remember here is that as long as the exhaust sound is loud, the back pressure must be small! The back pressure is small, fuel is consumed at low speeds, and low torque is lost, but the high-rev power and torque will be improved. It is impossible to have both at the same time. If you gain something, you will inevitably lose something...General modifications Players, I suggest that only changing the middle section and tail section or the middle section and front section is enough. The whole section is better, but considering the daily driving conditions, the increase in fuel consumption is a problem that cannot be underestimated.
How to choose an exhaust? What kind of exhaust is a good exhaust?
The most important thing about exhaust is welding and sealing to prevent air leakage. For ordinary exhausts, just remember that if the appearance is complete, the welding process is good, and it is firmly integrated with the original car, it is a good exhaust. As for performance, regardless of what I have said in detail earlier, the exhaust is actually a very common component, not as high-tech as you think. (But let me write at a deeper level, I can write more, of course it will involve a lot of concepts and vocabulary that you have not been exposed to, for the sake of simplicity...)
For more expensive brand exhausts and custom exhausts, there is nothing more than a difference in materials and technology. Expensive high-end brand exhausts are made of better titanium alloy materials, with prices ranging from 15,000 to hundreds of thousands.
So what does it say about custom exhaust? This is why many people have asked me about valve exhaust. It can be done by installing an electronic control system in the car, or more advanced, there is an internal damper in the exhaust pipe that can be automatically adjusted according to the engine speed, that is, a valve. Take the bilateral four-outlet exhaust as an example. At low speeds, the valve is controlled electronically or hydraulically to close one tail port, that is, when the valve is closed. At this time, the exhaust becomes bilateral and double-outlet, and the exhaust back pressure increases, which improves the low-end exhaust. Torque and fuel consumption are reduced, and noise is also reduced. The tail port can also be opened electronically or hydraulically, that is, the valve is opened. At this time, the exhaust becomes bilateral and four-out. The exhaust back pressure weakens, low torque is lost, fuel consumption increases, and the sound is enhanced, but the high-speed output becomes larger.
The advantage of this exhaust is that it has the best of both worlds. But the disadvantage is that it is relatively expensive, because this exhaust needs to be customized for the actual car and then tested on the DYNO machine. Generally, it is customized. The price is around $3,000, and big brands are more expensive.
My opinion on exhaust is that as long as you adhere to the concepts I mentioned above, no matter it is a brand from a major Chinese, American or European manufacturer, they are all the same. The exhaust itself is not very technical, and the focus is on the welding process. If you have money, you can use big-brand titanium alloys. If you have a small budget, low-grade stainless steel can also be used! Be sure to remember: when you really understand the principle and truly understand this article I wrote, why do you need to modify it, and what are the effects after modification? And after you have the basis for your own judgment and understanding, you will completely understand that although exhaust is different from what you think, it is not as complicated as you think.
About SNW
SNW is mainly engaged in the Manufacturing and Wholesale of automobile exhaust system parts,The exhaust system parts mainly includes exhaust manifolds, headers, downpipes, cat-back systems,aluminum alloy intake pipes, T-pipe, Y pipe, X pipe, H pipe and other performance parts。
