One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8?

2020/08/2117:28:05 car 2130

The much-anticipated Golf 8 will finally be introduced in China. As the cornerstone of the Volkswagen Group's traditional cars, the Golf 8 is not only a benchmark model in Europe, but also has a very high degree of attention in China. However, the power system of the domestic Golf 8 has caused many people to complain. The current EA211 1.4T engine is still retained. The new 1.5T Evo engine will not be available until 2023. Why does Volkswagen postpone the introduction of the 1.5T Evo engine? Today we will analyze:

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

1. What are the black technologies of Volkswagen 1.5T Evo

Volkswagen EA211 1.5T Evo engine is the latest generation engine of the EA211 series, which is actually in 2016 It has been listed in Europe, but has not been introduced into the country for a long time. The EA211 1.5T Evo generation engine is divided into high and low power versions. The two versions are as follows:

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

(1) The low-power 96kw version is the most innovative product of this engine With the two advanced technologies of Miller cycle and VGT supercharger, the compression ratio can reach 12.5:1, which is definitely a very high value in supercharged engines. The goal of the development of this engine is high efficiency, so performance is sacrificed.

(2) The high-power 110kw version does not use the Miller cycle combustion system and does not have a VTG supercharger. Only the 350bar direct injection system is upgraded, and the cylinder bore adopts APS atmospheric plasma spraying process with a compression ratio of 10.5. The performance is the same as the current domestically produced 1.4T, no improvement.

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

Let’s briefly talk about the representative technology used on the EA211 1.5TEvo most technically representative low-power Miller cycle engine:

1. Miller cycle combustion system

Miller cycle combustion system is simply to use the intake valve to close early to achieve combustion with an expansion ratio greater than the compression ratio, thereby reducing pumping loss and improving thermal efficiency. Early closing of the intake valve means that a lower intake valve lift and a shorter valve opening time are used to complete the closing of the intake valve before the piston reaches bottom dead center in the intake stroke. At this time, the air can no longer be sucked into the cylinder, but the piston is still descending. At this time, the air in the cylinder begins to expand and the pressure decreases. Wait for the piston to move to bottom dead center and then return to start compression. It can be imagined that due to the expansion effect of the air in the cylinder caused by the early closing of the valve, the actual pressure generated by the piston when the air is compressed to the top dead center during the compression stroke is much lower than that of the traditional engine. This means that the Miller cycle engine can use a relatively high compression ratio. Therefore, the compression ratio of the low-power version of EA211 1.5Tevo has reached a level of 12.5:1.

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

In order to realize the Miller cycle, EA211 1.5T evo redesigned the valve angle and designed a special low-lift intake camshaft. The use of a new airway design can achieve greater tumble movement in the cylinder and improve the oil and gas mixture state under the condition of early closing of the Miller cycle intake valve.

Miller cycle can greatly reduce fuel consumption, but at the same time, because the Miller cycle adopts the strategy of early closing of the intake valve to limit the maximum intake, engine performance will be limited. The following figure shows that the rated power of the Miller cycle version of the EA211 1.5T Evo generation engine is only 96Kw and the peak torque is only 200Nm, which is much lower than the performance of the current EA211 1.4T engine. However, under all engine operating conditions, the efficiency of the EA211 1.5T Evo-generation engine is 5%-15% higher than that of the 1.4T low-power version of the engine, and individual areas can even increase by about 30%.

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

2.VTG variable area turbocharger

VTG variable area turbocharger is widely used in diesel engines, but due to exhaust temperature, it has not been used in gasoline engines. breakthrough. Previously, Porsche tried to overproduce VTG variable interface turbochargers, but it did not continue due to the high cost.. With breakthroughs in turbocharger technology and material technology in recent years, gasoline engine VTG technology has returned. Volkswagen EA211 1.5T Evo can be said to be the world's first mass-produced gasoline engine with VTG variable interface turbocharger. The VTG variable interface turbocharger can keep the turbine high efficiency by adjusting the turbine blades under different working conditions, which can effectively reduce fuel consumption, improve the dynamic response of the turbocharger, and reduce the turbo lag effect (according to the comparative data published by Volkswagen It is shown that the response speed of the VTG supercharger is 35% higher than that of the traditional supercharger). At the same time, the high efficiency and low back pressure of VTG can make up for part of the power loss caused by the Miller cycle combustion system. Therefore, VTG technology and the Miller cycle combustion system are a very good technical combination.

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

2. Volkswagen plans to introduce the second-generation EA211 1.5T Evo2

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

Because the VTG supercharger can withstand temperature limitations, the current 1.5T Evo-generation Miller The power of the cycle version is only 96kW and the torque is only 200Nm, which is much lower than the current 1.4T. Volkswagen believes that direct introduction to the market is not acceptable, and the 1.5T Evo generation has entered the end of its life cycle, so Volkswagen plans to directly introduce the 1.5T Evo second-generation engine in China. Let’s take a look at the second-generation 1.5T Evo2 upgrades.

1, performance improvement

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

The second-generation 1.5T Evo2 continues to use the Miller cycle, but the power is increased to 118kW and the torque is 250Nm, which exceeds the current 1.4T performance. At the same time, the compression ratio is appropriately reduced from 12.5 to 11.5 in the first-generation Miller cycle version. This is also a compromise for performance improvement and domestic oil conditions.

2. The newly developed VTG variable area turbocharger

1.5T Evo2 has a significant improvement over the first-generation 1.5T Evo. The performance in the Miller cycle is increased from 96kW to 118kW. Due to the exhaust temperature control, the VTG turbocharger needs to be re-developed, and the withstand temperature of the turbocharger turbine will be increased from the original 880 degrees to 980 degrees, which can completely avoid the supercharger temperature limitation during engine operation. The use of the enriched injection strategy is beneficial to improve the engine efficiency under high-speed and high-load operation, and it can also reduce the particulate emissions caused by the enrichment at this time. This upgrade is based on the latest VTG turbocharger structure and material design. The previous VTG technology was mainly derived from the application experience of diesel engines, so the temperature tolerance could not be increased.

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

3. Post-processing adds GPF particle trap

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

In 2023, the country will implement the RDE actual road driving emission requirements in the country 6 emissions. Volkswagen plans to equip the 1.5T Evo second-generation engine with a particle trap GPF as standard to meet the requirements of RDE actual road driving emissions regulations. In this case, the 1.5T Evo2 second-generation engine will use a traditional three-way catalytic converter plus a four-way catalytic converter with GPF particle trap after treatment.

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

The following figure lists the relevant requirements for RDE actual road driving emissions in the country 6 emissions:

4, the introduction of a new APS cylinder bore coating process

The use of APS (atmospheric plasma spray) coating process on aluminum cylinders is a technological trend in recent years. The APS coating process forms a layer of iron alloy coating of only about 0.3mm on the surface of the cylinder bore to replace the original iron cylinder liner. This can reduce the weight, reduce the friction and wear of the piston plug ring, increase heat dissipation, and reduce the tendency of knocking. The APS coating on the 1.5T Evo generation engine has been applied to the high-power version. This time, the power of the 1.5T Evo second generation engine introduced in China has exceeded the 1.5T Evo generation engine, so the APS process has become a must. According to the information leaked by Volkswagen, Volkswagen has started building A in China since last year.The dedicated workshop of PS technology prepares for mass production of 1.5T Evo second-generation engine.

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

5, introduction of 48V light hybrid

1.5T Evo second-generation engine Another major change is the introduction of 48V light hybrid technology. The addition of 48V light mixing technology will further improve fuel consumption together with the Miller cycle efficient combustion system adopted by the 1.5T Evo.

One knife said: Why is the introduction of the EA211 1.5T EVO engine delayed for the Golf 8? - DayDayNews

To sum up, when GOLF was launched in China this year, the EA211 1.5T Evo generation engine has been on the market for 4 years and gradually entered the end of the life cycle. Volkswagen believes that the introduction of this engine at this time has no strategic value. Moreover, the core technology of the first 1.5T Evo is all on the low-power version. Volkswagen believes that the introduction of a new generation engine will reduce the power instead of domestic users. The final result is that Volkswagen decided to directly introduce the next-generation EA211 1.5T Evo2 second-generation engine that has been upgraded in terms of performance, emissions, and fuel consumption.

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