The intake pipe of the internal combustion engine refers to the gas pipe that introduces the gas required for combustion of the internal combustion engine device into the machine. The intake pipe must have enough flow area, avoid turning sudden change of section, improve the smoothness of pipe surface, etc., to reduce resistance. For this reason, linear intake system is used in high performance gasoline engine. In order to achieve the goal of high speed high power, we should design the throttle of air passage the length of intake pipe reasonably, arrange the appropriate volume of pressure stabilization chamber.

Intake pipe is one of the most different structural parts between electronic fuel injection engine carburetor engine. Because only air flows through the intake pipe of EFI engine, the dynamic effect (inertia effect fluctuation effect) of intake pipe should be fully considered in the design of intake pipe structure to improve the charging efficiency, the intake uniformity must also be considered. The intake system is dynamically matched with the engine, so the torque characteristics of the engine can be greatly improved in a wider speed range. In practical application, there are intake pipes with specific length designed according to specific speed range by using inertia effect fluctuation effect during intake, there are also intake pipes with variable length.