The exhaust manifold is an important component that collects the exhaust gases from each cylinder of the engine and discharges them out of the car. The efficiency of the entire exhaust system depends on the design of the exhaust manifold.
The exhaust manifold consists of an exhaust port mounting seat, a manifold pipeline, a manifold joint and a joint mounting seat. The exhaust manifold of general vehicle models is made of cast iron. The biggest disadvantages are its heavy weight and poor durability. , The exhaust interference phenomenon of pipelines with unequal lengths is serious, which greatly reduces the efficiency of the exhaust system.
Secondly, the most important step to improve the efficiency of the exhaust system is to replace the high-performance exhaust manifold. The so-called high-performance exhaust manifold is an exhaust manifold made of stainless steel with good heat resistance and corrosion resistance. First of all, high performance exhaust manifold The exhaust port mounting seat of the high-quality exhaust manifold is cut with a CNC lathe with extremely high precision to prevent air leakage.
There are two methods for pipeline processing. Generally, the whole vehicle model is made by bending the entire pipe, and then the pipeline is welded on the mounting base. The advantage is that the inner wall is smooth, the exhaust resistance is low, and the weight is light. The disadvantage is that the pipe diameter is easy to Dead knots are generated during the bending process, making it difficult to design a purely equal-length exhaust manifold with multiple lengths and multiple bends. The welded pipeline uses the pre-designed mold as a reference to cut pipelines at different angles and lengths, weld each pipeline one by one, and highly polish the weld marks and the inner wall of the pipeline. Although the welded exhaust manifold can be designed with pure equal lengths, it requires high welding technology and pipeline location design, and requires comprehensive inner wall polishing to achieve the smooth inner wall finish of the bent pipeline. Therefore, high-quality welded pipe exhaust manifolds will be much more expensive than bent exhaust manifolds.
The manifold joint is divided into two designs: multi-in-1 and multi-in 2-in-1. The former is a design that focuses on high-speed power output, and the latter is a design that focuses on low-speed torque output. The all-in-one design has the highest exhaust efficiency. Generally, the joint part of all-in-one products is a simple funnel shape. The disadvantage is that the exhaust gases discharged from each manifold cannot be evenly mixed and discharged, which may easily cause exhaust interference. The joint part of the exhaust manifold developed based on the racing exhaust system is a spherical expansion chamber structure, which can make the exhaust gas discharged from each manifold evenly and stably, prevent the occurrence of exhaust interference, and greatly improve the exhaust efficiency.
In recent years, there have also been high-performance exhaust manifolds made of titanium alloy materials. The biggest advantages of titanium alloy materials are high strength and light weight. With a very thin thickness, they can achieve greater strength and lighter weight than stainless steel materials. Moreover, titanium alloy materials have stronger heat resistance and can achieve better thermal expansion properties, which can further increase the exhaust temperature and greatly improve the exhaust efficiency.