The following key factors should be considered when selecting the rigid pipe of automobile intake manifold:

1. Material: The material of the hard pipe of the intake manifold directly affects its durability and performance. Generally, stainless steel, aluminum alloy and carbon fiber have high corrosion resistance and high temperature resistance, and are suitable for automobile air intake system. Choosing durable materials can ensure the stability of hard pipes in high temperature and high pressure environment.

2. Diameter and length: The diameter and length of the hard pipe of the intake manifold will affect the airflow velocity and flow rate, thus affecting the intake efficiency and performance of the engine. According to the specific needs and performance requirements of the vehicle, selecting a rigid pipe with appropriate diameter and length can improve the efficiency and performance of the air intake system.

3. Design and structure: The design and structure of the intake manifold rigid pipe are also important considerations. Some rigid pipes have streamlined design and internal coating, which can reduce airflow resistance and improve air intake efficiency. In addition, some rigid pipes also have noise reduction and shock absorption functions, which can improve the driving comfort of vehicles.

4. Installation and adaptability: When selecting the hard pipe of the intake manifold, its adaptability to the original air intake system of the vehicle and the convenience of installation should be considered. Some rigid pipes are designed to directly replace the original parts, which can simplify the installation process and ensure perfect matching with the vehicle system.

5. Brand and reputation: Choosing well-known brands and intake manifold rigid pipes with good reputation can improve product quality assurance and after-sales service. Well-known brands usually have rich production experience and technical strength, and can provide high-quality products and professional technical support.

To sum up, factors such as material, diameter and length, design and structure, installation and adaptability, brand and reputation should be considered when selecting the rigid pipe of automobile intake manifold. By comprehensively considering these key factors, high-quality intake manifold rigid pipe suitable for vehicle demand can be selected to improve the intake efficiency and performance of the vehicle.