Do you know the gibson exhaust systems?What the gibson exhaust systems it is?And have you heard the gibson exhaust systems?Or do you have some knowledge about gibson exhaust systems.Well ,put the gibson exhaust systems aside,let's talk about the exhaust systems.
Air intake system
The air intake system is composed of air filter, air flow meter, air inlet pressure sensor, throttle body, additional air valve, idle speed control valve, resonant cavity, power cavity, intake manifold and so on.
What is a variable valve timing?
First of all, talk about the general engine valve mechanism, we all know that the valve is driven by the crankshaft of the engine through the camshaft, valve timing depends on the angle of the cam shaft. When the engine is running, we need to make more fresh air into the combustion chamber,then the waste gas can be as much as possible the discharge chamber, the best solution is to let intake valve in advance to open, let the exhaust gate delay closing. In this way, in the intake stroke and exhaust stroke, the intake valve and exhaust valve will occur at the same time open the case, the overlap between the intake and exhaust valve is called valve overlap angle.
In an ordinary engine, an intake valve and an exhaust valve opening and closing time is fixed, valve overlap angle is fixed,it is according to the test and obtain the optimal gas distribution timing, in the process of engine running,it is can not be changed. However, the high and low speed of the engine, the exhaust flow and the combustion process in the cylinder are affected. When the speed is high, the intake air flow rate is high, the inertia energy is big, so I hope to open the valve early, late to close, so that the fresh gas smoothly into the cylinder, as far as possible some mixture of gas or air.
Whereas in at low engine speed, intake of low velocity, flow inertia energy is also small, if premature valve open, because at this time the piston is upstream of the exhaust, it is easy to push fresh air out of the cylinder, the air inlet but it is less, engine instability. Therefore, there is no any kind of fixed valve overlap angle set can make the engine at high and low speed can perfect output. If there is no variable valve timing technology, the engine can only be according to the needs of its matching models, optimize the choice of fixed valve overlap angle.
For example, racing engines generally use a smaller valve overlap angle, which is conducive to the power output at high speed. The common civil car is using a moderate valve angle, while taking into account the high speed and low speed is the power output, but at low speed and high speed will lose a lot of power.