car engine fuel supply system modified Principle

Supply system is divided into two carburetors and fuel injection systems, but the power output, fuel efficiency, air pollution, reliability. . . . All the parties concerned, the carburetor fuel injection system than can be said nothing, so you can say: carburetor era has passed, it has become a historical term, value-free discussion. So, we are talking about is a single engine fuel supply system means the fuel injection system. Fuel injection system is composed of conveyor systems, sensor systems, computer control system components. It works in simple terms is the use of pressurized gasoline pump gasoline later sent to the high pressure from the tank through the regulation of the pressure regulator, oil pressure in the system is maintained at 2.0 to 2.5, that is, to maintain the pressure in the fuel injector of 2.0 to 2.5. At the same time by the sensor and the operating state of the engine intake air in the form of a transmission voltage signal to supply the computer (ECU: Electronic Control Unit), ECU voltage signal to be analyzed according to the calculated desired fuel injection amount, that is, after the calculated injector fuel injection time, and then the signal transmitted to the nozzle of the injector coil, fuel injection nozzle accept signals the fuel injection valve is opened, then sprayed gasoline into the intake inlet in front of the party the manifold, and then open the door with the inlet into the cylinder （bmw turbocharger）.

Classification injection system

First, according to the nozzle position classification:

1, after the throttle body injection, also known as a single point, use only one or two branched nozzle, mounted on the top of the throttle valve to the lower pressure of the discharge gas, gasoline and air flowing through the throttle valve to form a mixed gas , you must first tube and then from the cylinder through the intake valve into the intake manifold. However, when the oil and gas flowing through the intake manifold, some oil and gas in the manifold wall attachment, and will vary depending on the shape of the intake manifold, the length of each cylinder caused by the uneven distribution of the mixture. Because oil and gas from the throttle valve to the cylinder an inherent time delay, so the reaction will slow the engine during acceleration.

2, intake port injection, also known as multi-point injection, each with a nozzle inlet door before each cylinder, inlet valve alignment to the high pressure of 2 to 5 gasoline spray, while the intake manifold together with air into the cylinder tube to form a mixture. As a result of oil and gas into the mixing ratio of each cylinder to be average （vw turbo）.

Second, according to the injection mode Category:

A continuous jet, also known as mechanical jet, nozzle when the engine is running at constant fuel injection, and injection quantity is controlled by varying the supplied pressure is reached.

2, jet program, the use of electronic fuel injector, the injector fuel injection when needed coil is energized, the plunger because the role of magnetic force and raise up the injector nozzle can. Fuel injection quantity is controlled by the length of the fuel injection time, in microseconds (ms). Due to mechanical injection is an outdated design, so far almost all types of vehicles on the market use efficiency and economy better procedures jet. The single point of injection in addition to lower prices, simple structure, but also without any comparable multi-point injection of the Department, and the carburetor Moreover, it also has a lot of the same disadvantages (low efficiency, each cylinder uneven distribution of oil and gas), so multi-point injection (MPI) can be said to be the mainstream of modern jet fuel supply system.

Third, according to air flow detection mode Category: intake air into direct and indirect detection methods into two categories, one is the intake manifold absolute pressure sensor (MAP Sensor: Manifold Absolute Pressure Sensor) measured intake manifold pressure and engine speed indirect calculable. Another is based on the air flow meter measured directly. The more common air flow meter has three kinds: wing plate, hot wire, Kalu Man vortex. Ó species currently on the market is based on MAP and hot wire air flow meter for the bulk.

Calculate the amount of oil

The amount of supply of fuel injector is the length of time to calculate the fuel injection, fuel computer (ECU) according to the compensation signal of air flow, engine speed, and the various sensors are provided, the use of pre-set programs calculating oil the time required for oil, the oil program, we can use a graphical approach to performance. The ECU calculates the fuel injection time (basic injection time), (compensated injection time), and the sum of (inactive injection time), in units of microseconds (ms), 1ms = 0.001 seconds. Wherein the amount of gasoline injectors in unit time is determined by the spray nozzle itself bore size and the size of injection pressure.

First, the basic injection time basic injection time is determined by the intake air (here refers to the weight) and the engine speed of the decision. When you depress the accelerator pedal controls the throttle valve opening angle is, the greater the degree of opening of the larger air intake, fuel computer according to the air flow meter measured intake air to the engine speed and the time and pre-established after comparing a given supply program calculates the required fuel supply and injection time relative.

Second, the compensation compensation jet injection time is generally referred to (speed), which is composed of various sensors detect the engine was operating conditions and load, the signals passed after the computer (ECU), calculate the required additional fuel supply to the engine to maintain a stable and smooth running. Jet set compensation program is a complex task, but also vary by car.

Adapted oil supply system

Optimum air-fuel ratio to the engine is 14.7: 1, but if the engine To require output to be high at high speed, high load, generally to improve the air-fuel ratio to 12: 1 to 13: 1. Adapted oil supply system is to (raise the right amount of fuel supply at the appropriate time), so that air-fuel ratio moderately large, this (timely) and (in moderation) is to determine the merits of oil supply system, smart enough basis. Jet fuel supply system can be modified to change the hardware and changed into two major categories of software, hardware mesh change is to increase the amount of oil per unit of time. Software major change is to change its oil program, since the original car's oil program is considered the emission control, fuel economy, the stability of a given operation, engine durability of the resulting material is set, so the horsepower output performance, often unable to achieve performance-oriented users' needs, such as high-speed all the most ardent demand, high load performance, often showing insufficient amount of oil predicament, then it depends on the modification of software to achieve. Below we will supply systems for the conversion project, setting them （vw turbocharger）.