As a component that directly determines the power of the fuel vehicle, a good engine can even bring huge sales and profits to the entire brand. For example, Volkswagen's EA888 and GM's 2.0T variable cylinder engine have given many of its models a powerful selling point. In contrast, Japanese brands, in addition to some small-displacement turbines, are currently naturally aspirated engines oriented by fuel saving. But in fact, these Japanese brands have a lot of high-performance turbines for sale overseas! If these engines can be introduced into The Country, it will undoubtedly be a feast for car fans! Let's talk about the Japanese high-performance engines that should be introduced into The country!
As a Japanese brand that has a deep sense of sportsmanship in the marrow, you can find three things in common in every Mazda model, that is, excellent steering feel, excellent driving quality and first-class power response. However, this brand that flaunts the joy of driving, there is currently no car in China that can make people drive to the blood. The 2.0L Unxella accelerates nearly 10 seconds per 100 kilometers, and the 2.5L CX-5 and Atez 100 kilometers accelerate 8 seconds away, so it can be said that Mazda's power has dragged down their outstanding chassis. But friends who know Mazda should know that the Overseas Market's Unxella, CX-5, and Artez have long since become the same level of horsepower kings, because Mazda has equipped them with a "god machine", that is, mazda Chuangchi Blue Sky series SkyActiv-G 2.5T engine.
Back in 2016, Mazda released this 2.5T four-cylinder engine with a maximum power of 253 horsepower and a peak torque of 432 Nm. Although the power is not impressive, the torque of more than 400 Nm can even be comparable to the 4.0L V8 self-priming engine! After switching to the 2.5T engine, the 100 km/h acceleration of artez was shortened from 8 seconds to 6.2 seconds from 2.5 liters! CX-5 100 km/h acceleration is reduced from 8.3 seconds to 6.1 seconds for the 2.5L model! The 100-kilometer acceleration of Unxella has been shortened from 9.4 seconds to 5.6 seconds in 2.0L! A 2.5T engine directly brings Mazda's flagship models into the ranks of performance cars. In addition to the strong power, the 2.5T turbine hysteresis is also very low, while the fuel consumption is also very good, at some speeds the fuel saving performance even exceeds its own 2.5L self-priming. And with the advent of this engine, it also proves that Mazda-built supercharged engines can still achieve the industry's first-class level.
VTG variable section turbine
So where is the "first-class" of this engine? I think all fans have heard of Porsche's VTG variable section turbine, which adjusts the change of turbine cross-section angle so that the turbine can have good boost performance and response speed at high/low speeds. But in addition to Porsche, there are few ordinary family cars using VTG technology, this is because the exhaust temperature of the gasoline engine is as high as 1000 ° C, VTG in order to withstand the ultra-high temperature, it must use expensive high-temperature resistant materials, which will undoubtedly greatly increase the manufacturing cost of the engine.
2.5T spiral variable flow turbine
The Mazda 2.5T takes a different path and achieves the same effect through a technology called a spiral variable flow turbine. As shown in the figure above, Mazda's variable flow turbine intake duct is separated into two lines, one thick and one narrow, and the thicker pipe also adds a variable valve (yellow circle in the picture above). At engine speeds below 1650 rpm, the turbine's variable valves (yellow circle above) close, equivalent to exhausting the turbine only through narrower lines. According to the law of fluid mechanics, the smaller the pipe diameter and the greater the pressure when the gas flow is constant, so the turbine can be blown to a higher speed at low speeds, thus providing a higher boost value for the intake end. Compared with single-turbo solutions including twin-scroll tubes, Mazda's variable flow turbines can increase their low-rotational torque by 20-25%, and they can output 350 Nm of torque at 1250 rpm, with a power response comparable to large displacement self-priming!
As the speed exceeds 1650 rpm and the amount of exhaust gas discharged by the engine increases, this variable valve opens to provide a channel for more exhaust gases to flow into the turbine, ensuring that the engine can still produce power stably at high speeds. Because both high and low speeds are taken into account, Mazda's 2.5T combines the smoothness and responsiveness of a self-priming engine, as well as the high power and torque of a turbocharged engine. Seeing this may be a friend worried, this 2.5T engine is so powerful, will it be very fuel-intensive? In fact, compared with the performance of the 2.5L self-priming engine, the increase in fuel consumption of this 2.5T is not much.
After the actual measurement of the EPA fuel consumption in the United States, on the Artez, the fuel consumption of the 2.5T version is 9L/100km, while the fuel consumption of the 2.5L version is 8.1L/100km; on the CX-5, the fuel consumption of the 2.5T version is 9.8L/100km, and the fuel consumption of the 2.5L version is 9L/100km. It can be seen that this 2.5T in the power than 2.5L self-priming increased by 25%, torque increased by 70%, the comprehensive fuel consumption increased by only 10%, this deal is not cost-effective?
In terms of price, the 2.5T Atez in the US market is about $3,100 more expensive than the 2.5L self-priming version, which is close to 20,000 yuan. To be honest, if you can make the domestic 2.5L Artez users plus 20,000 pieces of upgrade 2.5T, I believe everyone must be very willing! Not to mention that 2.5T can also raise the positioning of the entire brand, Mazda is ready to take the luxury brand route after that, it is certainly indispensable to have a high-horsepower engine that can support the table! More importantly, if Mazda's 2.5T is introduced into China, Mazda will suddenly become a benchmark for Japanese performance cars, and from now on, no one will say mazda "bare roar and don't go"!
When you think of Subaru, the first thing that comes to mind is the horizontally opposed engine and the excellent all-wheel drive system, and then it is taken for granted that Subaru's models are very sporty. But in fact, Subaru is like Mazda, although the chassis quality is outstanding, but there is no excellent performance engine in the country. At present, in the Subaru models on sale in China, in addition to the sports car BRZ, the rest of the cars, crossovers, SUVs, all use the old 2.0L, 2.5L self-priming engines, and none of the models can run into 10 seconds with 0-100km/h acceleration! Not only that, in addition to the acceleration can not catch up with the mainstream level, the domestic active Subaru 2.0L, 2.5L engines are already developed 10 years ago, so the fuel consumption performance is not ideal.
For example, the Subaru XV, a crossover SUV equipped with a 2.0L engine, consumes 7.2L/100km of NEDC fuel. The Toyota's larger, heavier, and 2.0L four-wheel drive RAV4 also consumes only 6.3L/100km of NEDC fuel consumption, a difference of nearly 1L. If the weak power only affects the user's experience, then the high fuel consumption is directly related to the survival of enterprises in the context of energy conservation and emission reduction.
Faced with the severe global situation of energy conservation and emission reduction, Subaru urgently needs to develop a high thermal efficiency engine to balance fuel consumption and power. So in 2020, Subaru introduced a 1.8T engine with a thermal efficiency of 40%, code-named CB18. In terms of parameters, Subaru's new 1.8T engine has a maximum power of 177 hp and a peak torque of 300 Nm. The power is better than the current domestic Aohu's old 2.5L self-priming engine with a maximum of 168 horsepower and 252 Nm. In terms of fuel consumption, the overseas replacement of 1.8T engines, WLTC working conditions 100 km fuel consumption of 7.7L, compared to the 2.5L model of 8.6L/ 100km is nearly 1L lower! Therefore, if the domestic foresters and Aohu can also be replaced by the latest 1.8T engine, it will not only be improved in power, but also the cost of the car used by the owner, as well as the fuel consumption of Subaru's enterprises, which is simply a good thing!
Toyota Dynamic Force engine
At the technical level, I believe that everyone will be surprised at first glance to see the thermal efficiency of 40% of subaru's 1.8T engine, after all, Toyota's current dynamic Force series 2.0L and 2.5L engines have a thermal efficiency of 40% in its non-hybrid version. It should be known that the self-priming engine will be easier to achieve high thermal efficiency due to the low intake temperature. Turbocharged engines have to reduce the compression ratio to prevent knocking due to the high intake air temperature, so the thermal efficiency is inherently inferior to self-priming. It can be seen that Subaru's 1.8T as a turbocharged engine, in order to achieve the same 40% thermal efficiency as Toyota's self-priming, it is bound to use more advanced technology than Toyota's 2.0L and 2.5L engines.
First, Subaru used the extremely rare and costly "thin burn" technology on the new 1.8T engine for the first time. What is thin burning? It actually refers to the ratio of air in the cylinder to gasoline, and the amount of air is greater than the standard level. In the standard case, the engine's gas mixture will be matched by 14.7 kg of air and 1 kg of gasoline, which means that the ratio of air to fuel is 14.7:1. If the ratio of air to gasoline is increased to 14.8:1, it belongs to more air and less gasoline, which is equivalent to the thinner gasoline in the gas mixture, which is the so-called "thin combustion".
From a thermodynamic point of view, thin combustion can reduce the combustion temperature and pump air resistance, thereby improving the thermal efficiency of the engine. But it is well known that if the content of air in the cylinder is much higher than the standard value, there will be a situation where the gas mixture cannot be ignited by the spark plug. But Subaru did not believe in evil, and directly increased the air content by nearly 1 times, so that the air-fuel ratio of this 1.8T engine reached 29.4:1 that could not be ignited under normal circumstances... So what magic did Subaru cast to make this 1.8T engine ignite normally at an ultra-high altitude fuel ratio?
Due to cost considerations, the injectors of the general in-cylinder direct injection engine are arranged obliquely on one side of the cylinder. However, due to the thin combustion technology of Subaru's 1.8T engine, the oil and gas mixture is not easy to ignite, so Subaru placed the fuel injector on the top of the combustion chamber, next to the spark plug. In this way, as soon as the injector is injected with fuel, the spark plug can ignite it at the highest concentration of gasoline. At this point, after ensuring that the oil-gas mixture can be ignited, the next step is to consider how to conduct the flame to the entire cylinder and ignite the remaining thin oil-gas mixture.
Left: Small rolling / Right: Large rolling
In order to speed up the conduction speed of the flame, this 1.8T engine uses an 80.6mm bore x 88mm stroke, which is more inclined to a long stroke design than the 78.8mm bore x 82mm stroke of Subaru's previous 1.6T engine. In the case of the same volume and speed, the longer the cylinder stroke, the faster the piston runs, and as the piston speed increases, the air velocity in the cylinder will also become faster. Therefore, the long stroke increases the rolling flow in the cylinder, thereby increasing the conduction velocity of the small flame that is ignited by the spark plug. This design idea of compensating for low gasoline concentrations by speeding up combustion was already validated by Toyota when it launched the TNGA Dynamic Force series engine in 2016.
After solving the combustion problem of thin combustion, another problem ensued, because the air-fuel ratio became larger than the gasoline burned per unit time, so when the engine was in thin combustion, the output power naturally became very low. In order not to affect the absolute power experience of the vehicle, the 1.8T engine is set to use a thin combustion operating logic only when the speed is below 2400 rpm. Fortunately, thanks to the presence of a turbocharger, the engine can output a maximum torque of 300 N·m from 1600 rpm, so that the low-speed power of the vehicle is guaranteed. For daily driving, because the speed of the engine usually does not exceed 3000 rpm, the engine will be in a highly efficient thin combustion state for most of the time to reduce the cost of use of the owner. When the owner needs to call absolute power to overtake, once the speed exceeds 2400rpm, the air-fuel ratio of this 1.8T engine will switch from 29.4:1 to the normal 14.7:1, thereby ensuring the power output at high speeds.
In summary, although this 1.8T engine is not particularly exaggerated in terms of parameters, this ability to significantly reduce fuel consumption under the premise of slightly stronger power than the current 2.5L self-priming is obviously very suitable for the current era of energy saving and emission reduction.
In addition to the more long stroke of the cylinders, the spacing between each cylinder of the new 1.8T engine has been shortened from 113mm of the old 1.6T to 98.6mm, which finally makes the length of the new 1.8T engine 40.3mm shorter than the old 1.6T, and the weight is also reduced by 14.6kg. The shorter engine also means that the engine position in the cabin will be more backward, plus lighter weight, so the center of gravity of this 1.8T engine will be more backward, which can help the vehicle achieve a more balanced front and rear counterweight, further improving the dynamic performance of the vehicle.
As for the price, taking the Japanese version of the Forester as an example, the 1.8T model is 121,000 yen more expensive than the 2.0L version, which is about 6340 yuan. According to the domestic 2.0L forester starting price of 223,800, after the replacement of the 1.8T engine is still less than 230,000, I believe that you are not so sensitive to the price of forester owners are willing to spend more than these thousands of dollars, right? It is a pity that at present, Subaru has no plans to introduce the new 1.8T into the country, if it can be introduced in the future and installed on the Forester, Auror tiger, XV models on sale, then Subaru's competitiveness in China is bound to be improved.
Since the Tule Y62 cannot be listed because of the national 6 emissions, Nissan's current hardcore off-road vehicles in China are only Tuda and the pickup truck Navarre on the same platform. However, both cars only provide 2.5L self-priming gasoline engines, with a maximum power of 193 horsepower and a maximum torque of 245N·m, which is obviously not enough for a hardcore off-road vehicle weighing more than 1.8 tons. It should be known that Nissan Tuda / Navarre has a 2.3T twin-turbo diesel engine in overseas markets, although the maximum power of 190 horsepower is not a bright spot, but the maximum torque has reached a strong 450N·m, which is very suitable for off-road climbing and pulling goods, which is quite suitable for the positioning of Tuda / Navarre. More importantly, Nissan's 2.3T diesel engine also has many highlights at the technical level.
Nissan 2.3T twin-turbo diesel engine
Friends who have a certain understanding of diesel engines should know that diesel engines with a displacement of 2.5L and below will usually use the form of single turbocharging, while Nissan rarely carries two turbines for this 2.3T diesel engine. Not only that, but the two turbines also use a combination of one large and one small, which will greatly help the vehicle's power response as well as the low torque output.
At low rpm, due to the small exhaust volume of the engine, as shown in the figure above, the ECU closes the bypass valve at the intake and exhaust ends, allowing the exhaust gases to preferentially drive the small turbo to supercharge. At this time, due to the low inertia of the small turbine, the hysteresis of the turbine will be smaller, which can help the vehicle obtain strong power at low speed while ensuring the response speed of the power.
In the case of rapid acceleration, heavy lifting, climbing and other working conditions, the engine speed will increase, the exhaust volume will also increase, at this time the ECU will open the bypass valve at the intake and exhaust ends, so that most of the exhaust gas directly into the large turbine, and push the large turbine for pressure. In this way, as the two turbines of the large and small are switched between high and low speeds, the peak torque platform of the engine can be covered in the range of 1250-3500 rpm.
In addition, because the diesel engine is inherently high thermal efficiency and low fuel consumption, nissan's 2.3T diesel engine can also form a dimensionality reduction blow to the current 2.5L self-priming gasoline engine in terms of fuel consumption. The 100-kilometer comprehensive fuel consumption of the overseas version of Navarre 2.3T diesel version is only 6L, while the domestic Navarra 2.5L comprehensive fuel consumption is 9.6L/100km, which is equivalent to nearly 1 times the engine torque, and the fuel consumption can be lower by one-third.
Power has always been the short board of domestic Toyota models, a number of 2.0L, 2.5L self-priming engines by the opponent's turbo pressure is overwhelmed, and the North American market large-displacement V6 engine is not introduced. In fact, with the release of the new generation of Lexus NX last year, a new 2.4T four-cylinder engine was born, which is currently only used in the overseas version of the NX 350. This engine, code-named T24A-FTS, will replace the 2GR 3.5L V6 engine on the previous Highlander, RX, American Version of The Asian Dragon, Camry and other models, becoming the main model of the Toyota Group.
In terms of parameters, the new 2.4T has a maximum power of 279 hp and a peak torque of 430 Nm, which is equipped on the NX 350 and accelerates from 0-100km/h measured overseas in only 6.3 seconds. In contrast, the previous generation of the NX 300, equipped with a 238-horsepower, 350N·m 2.0T engine, has a 0-100km/h acceleration measured at 7.6 seconds, and there is a significant difference in performance between the two engines.
More importantly, the new 2.4T engine, although more powerful, has not increased fuel consumption. For example, the NX 350 with a 2.4T engine has a combined fuel consumption of 9.4L/100km under the U.S. EPA condition, and the previous generation NX 300 with a 2.0T engine has the same fuel consumption as 9.4L/100km under the same operating conditions. This is equivalent to a 17% increase in horsepower, a 23% increase in torque, and an acceleration of more than 1 second to 100 kilometers, but the comprehensive fuel consumption has not changed. In addition, compared with the 306 hp and 362N·m of the current 2GR 3.5L engine, the new 2.4T engine is slightly lower in horsepower by 27 horses, but the torque is nearly 70N·m greater, and the fuel consumption tested on the bench is also reduced by 10.5%. The reason is that this engine uses many new technologies, so that the thermal efficiency has reached 38%, compared with the previous generation of 2.0T 8AR 36% has been significantly improved.
Just like the new Subaru 1.8T engine mentioned above, Toyota's 2.4T also uses a mid-mounted fuel injector design, which is also toyota's first engine to use a mid-injection fuel injection. Compared with the side injection, the intermediate injection will be more conducive to the ignition of the spark plug because it is closer to the spark plug, which can make the gas mixture burn more fully and reduce pollutant emissions. But in order to ensure that the new 2.4T engine can be comparable to the power level of the old 3.5L V6 engine, Toyota did not reduce the air-fuel ratio for this 2.4T engine like the Subaru 1.8T. In addition, this 2.4T engine also retains the D-4ST dual injection technology, and the ECU can choose intake manifold injection or direct injection in the cylinder according to different working conditions to maximize power and emissions.
The reason why the thermal efficiency of this 2.4T can reach 38% is mainly due to the high compression ratio of 11:1. After all, in general, the higher the compression ratio means the higher the thermal efficiency, and the higher the thermal efficiency means the more fuel efficient. At present, most of the high-power engines on the market have a compression ratio of about 10:1, and toyota's 2.4T 11:1 compression ratio has reached the top level in the supercharged engine. Like the Subaru 1.8T, Toyota's 2.4T also adopts a long-stroke cylinder design, with a bore x stroke of 87.5mm x 99.5mm, a stroke/bore ratio of 1.13, even larger than subaru's 1.8T of 1.09, which can increase the rolling flow, improve the combustion speed, and effectively improve the thermal efficiency.
Variable displacement oil pump
Like all TNGA engines, this 2.4T is also equipped with a variable displacement oil pump. As we all know, the oil pump is connected to the engine crankshaft, which will consume engine power to a certain extent. The variable displacement oil pump can actively adjust the flow and pressure of the oil pump according to the different loads of the engine under different working conditions, so as to meet the needs of engine lubrication while minimizing the consumption of engine power. Not only that, in order to ensure the stable output of engine power, Toyota also equipped this 2.4T with an uncommon water-cooled intercooler, which can reduce the intake air temperature and improve performance and efficiency.
If this 2.4T engine can be introduced into China and assembled on the same platform as NX ES, at least the number of people who use "mobile barricades" to ridicule ES should be much less, right? In addition, the T24A engine will also be equipped with new cars to be released in the future, such as the next-generation Lexus RX and the 16th-generation Toyota Crown, and the performance is very worth looking forward to. As for the price, taking the AMERICAN version of Lexus NX as an example, its 2.4T four-wheel drive model is 3600 US dollars more expensive than the 2.5L front-drive model, which is about 23,000 yuan. And the domestic 2.5L front-drive NX starting price of 318,800, according to the price difference in the United States to calculate, the domestic 2.4T four-wheel drive NX price should be about 340,000, I believe that all NX owners are willing to add money to make their NX into a 0-100km/h acceleration only 6.3 seconds of express car, right?
It is not difficult to see from the above that Japanese car companies have a lot of good things overseas, but they do not introduce high-performance engines into The country, in fact, it is not a difference. More because China pays more attention to fuel consumption and emissions, Japanese car companies will give priority to bringing their most "environmentally friendly" technologies to the domestic debut. For example, China is the first country in the world to enjoy toyota's M20A engine, and Nissan also debuted the e-POWER hybrid Xuanyi in China. So it's not that Japanese car companies don't give us good things, it's just that their high-performance products are really not suitable for China. If these four engines can be introduced into China today, I believe that it will greatly reverse everyone's impression of the poor performance of Japanese cars. Unfortunately, at present, the major Japanese manufacturers do not seem to have the intention of introducing these engines into The country, as fans, we can only look at the photos and parameters of overseas models...