#New Year Hot Sale# Exhaust System and Modified Exhaust， GRWA2022 starts, and the series of products are on sale!（1）

In the modification involving the power section, modifying the intake and exhaust is often referred to as a designated action. By replacing the high-performance intake and exhaust system of the vehicle, the engine can be sucked in multiple rows smoothly, thereby improving the power performance. This is also the simplest and most effective modification method. Relatively speaking, simple modified exhaust is more common in China. The important reason is not only the improvement in performance, but also the beautiful exhaust pipe and the beautiful exhaust sound can attract the attention of passers-by, which is the main purpose of modifying the exhaust. The more complex modification and modification of the complete system are relatively common in the world. After all, the different laws and regulations of various countries are also a problem that car modification has to face.

As you hearing the blood-boiling exhaust sound, you are reminiscent of car modification, or many people's understanding of modified cars is that there must be exaggerated noise (of course, this understanding is one-sided). It can be seen that the modified exhaust system is common in car modification. This time we will talk about the common misunderstandings in the modified exhaust system.

ONE、Common Mistakes in Retrofitting Exhaust Systems

Mistakes1：Poor performance of the original exhaust system

The exhaust system used in the original factory has been repeatedly tested by the manufacturer, and it is a product designed for the dynamic performance, environmental performance, fuel economy and production cost of the vehicle. It is a more reasonable match with the powertrain of the vehicle, especially for small-displacement models with weak power, the original exhaust is usually not too smooth, but this design optimizes the low-torque characteristics of the small-displacement engine itself, and proper back pressure will The exhaust resonance effect (described in detail later) can be produced, which can improve the exhaust efficiency at low and medium speeds, and is more suitable for urban road use.

For some high-performance models, an exhaust system with lower back pressure is used in the original design to improve the maximum power output of the engine. Usually, the optimized exhaust manifold design, straight large-diameter pipes, and more tail throats are used. And the loud exhaust sound is their common feature.

For some performance models, the original exhaust system will use an exhaust design with lower back pressure, and even use an equal-length exhaust manifold.

Mistakes2：The louder the sound, the greater the horsepower. Only changing the tail section can significantly increase the power output.

The concept that the louder the sound, the greater the horsepower, is wrong. For the exhaust system, the exhaust tail section and the middle section are mainly responsible for the muffler effect, especially the tail section muffler (also known as the muffler drum) is more important. In fact, just by modifying the in-line tail section, you can get a lot of exhaust sound, but at this time, the power output of the engine will hardly change much. The reason is very simple, the exhaust gas from the engine needs to pass through the exhaust manifold (the part closest to the engine, connected to the exhaust hole of each cylinder), the three-way catalyst (after the exhaust manifold, responsible for the conversion of harmful gases) ), followed by the middle exhaust section (reducing resonance and reducing noise), and finally the exhaust tail section (responsible for noise reduction) that we can see at the rear of the car, and before the exhaust tail section, each part will Exhaust creates resistance, so loud sound doesn't mean big horsepower.

Just modifying the exhaust tail section will not increase the horsepower of the car (even if the increase is small and negligible), and if the entire exhaust pipe is replaced with a high-performance model, it will help a lot in horsepower (especially It is the intake system that has also been modified). The high-performance exhaust pipe is thicker than the original one, with a smoother inner wall and less curvature. These designs allow a large amount of exhaust gas generated by the engine to pass through smoothly at high speed at high speeds, which can significantly improve exhaust efficiency.

Don't believe the claims of mufflers produced by unknown small workshops that increase power without sacrificing low torque. In China, where horsepower machines are relatively popular, such deceptive modified products have long been confirmed (a 1.8-liter family car is greedy to replace an unknown brand of mufflers cheaply, and the highest power measured on the horsepower machine is higher than the original factory, worse).

In fact, the above two questions have already been answered when the original accessories are good, why do they need to be modified?

In layman's terms, original parts are only the most rational choice for city cars; and modified parts are the most cost-effective choice for cars; in simple terms, original parts make the car achieve a balance in all aspects through calculation formulas, which can be understood as satisfying all aspects of the car. The demand can also be said to be the most "moderate" way; and the modified accessories can enhance the "practical value" of the car through the most intuitive and effective means, which is the longing choice of many groups who are keen on driving fun.

Mistakes3：The thicker the exhaust pipe, the better, and the lower the exhaust back pressure, the better.

Friends who have a certain understanding of the exhaust system will know that the most important factor affecting the exhaust performance is the back pressure. The level of the back pressure can directly change the power output characteristics and maximum power of the engine. But does the lower the back pressure, the better the power performance?

Of course not, first of all we have to figure out the indicators to measure dynamic performance. For example, a performance model that is good at high rpm output such as the Honda S2000, drivers who understand the power output characteristics of this car can drive it quickly and smoothly, but for ordinary people, the output characteristics of low torque and lack of output are very uncomfortable. It feels good to drive (not suitable for congested city roads), and at the same time, it does not feel how excellent the dynamic performance of this car is. This principle also applies to the modification of the exhaust system. If the back pressure is too low, the exhaust will be too smooth in the low-speed state, and the airflow speed will be slowed down, which will affect the exhaust efficiency at low speed. Torque output drops. The modified exhaust system must be modified according to your driving habits and needs.

Note: When modifying the exhaust, you must modify it according to your driving habits and needs

When modifying the exhaust system, you need to consider the power output characteristics of the vehicle and your own driving habits. For car owners who feel that the low-speed torque output is not ideal, modifying the exhaust is not a good choice. Because the modified exhaust is basically optimized for performance in the mid-to-high speed area, this modification is usually at the expense of losing some low torque. Of course, some professional refit factories have now introduced variable valve exhaust, which takes into account the back pressure requirements at low speeds, and can control the valve to make the exhaust smoother at high speeds. The only downside may be that the price is a little expensive.

Two、Fundamentals of Retrofit Exhaust

Factors such as manufacturing costs aside, usually the original model will be designed with the engine output characteristics suitable for daily use. Especially when driving on urban roads, the full low-speed torque output can take into account the advantages of driving well and saving fuel. Appropriate high exhaust back pressure design can ensure the output characteristics of the engine at low speed and high torque, but the exhaust system of this design will form resistance at high speed, resulting in the obstruction of maximum power.The modified exhaust reduces the exhaust back pressure through different designs and materials, and at the same time can improve the intake efficiency of the engine, so as to achieve the purpose of increasing the maximum power output and changing the torque output characteristics.

At the current stage of the development of modified exhaust, most countries in the world have very clear requirements for materials and environmental protection. Therefore, when choosing brands and products, there should be no chance of luck. Taking three-way catalytic converters as an example, many brands cannot provide products that truly meet the quality requirements. The lack of precious metals and the immaturity of carrier technology will affect the product sales market. The annual inspection will really bring losses to yourself.

GRWA，CHINA’S #1PERFORMANCE EXHAUST BRAND，with strict quality inspection standards and detailed quality inspection certificates, the product has been in the market for many years and is a very well-known brand；

The products are diverse and the technology is mature. Construction will start in the new year of 2022, and a full range of brand products of its exhaust system will be on sale, including not only carriers, tail pipes, bellows, etc. that can be mass-produced, but also various manifolds with a certain production process. Mufflers, elbows and other products.

As the first brand of high-performance exhaust gas in China, GRWA is willing to carry out new cooperation with you in 2022, with high-quality service, guaranteed orders, stable supply, and reasonable price~~

More surprises are waiting for you to unlock!