The first performance test of Zhiji L7, what Porsche is this level？

Zhiji L7 Angel Wheel will be delivered in the first quarter of next year at the earliest, and the interior of Zhiji L7 will be officially made public at the upcoming Guangzhou Auto Show. This new electric luxury brand, which was established only one year ago, is accelerating its way to people with a speed that exceeds that of any previous car companies.

This time, we got a close look at the excellent performance of Zhiji L7. Although it is still an engineering vehicle, the mechanical hardware and adjustment of the vehicle have been locked. In a word, it is a product with performance comparable to that of a million-level high-end luxury car, and it is the most fun car in the history of SAIC.

In a test field, the ground was printed with black marks left by the friction between the tire and the ground after drifting in circles. A senior technician said that this is the first time that a performance car has left its mark since the test site was put into use, and this mark was left by Zhiji L7.

What kind of performance car has Zhiji built? The authoritative data measured by this group of national motor vehicle product quality inspection and testing centers can make you better understand.

The acceleration of 3.87 seconds, the braking performance of 32.69 meters and the steady-state maximum lateral acceleration of 0.968G can be seen in the video at the beginning of the article.

In addition to the official measured data, there are also excellent performance, such as more than 10 consecutive full-power ejection starts, 50: 50 front and rear car body weight ratio, 0-100% real-time dynamic intelligent adjustment of front and rear axle torque, 100% kinetic energy recovery efficiency and 10.8m turning diameter. Any one of these achievements is worth talking about a lot, and the space problem is only briefly discussed from two hardware modules: motor and brake.

Heat dissipation is a systematic project for electric drive, and it is also one of the most difficult problems to solve. At present, the common practices in the industry are oil cooling heat dissipation, flat wire winding and motor thermal management system. Zhiji L7 has brought in a "Ao Bai" family bucket, and collected these mainstream schemes.

Compared with Tesla’s winding end oil cooling scheme, Zhiji L7′ s straight waterfall oil cooling structure can cool the winding end and core at the same time, which improves the sustainability by 46% compared with the current mainstream water cooling scheme. This innovative motor cooling structure has been applied for an international patent.

In addition, this motor also uses 8 layers of Hair-pin flat wire winding, which is simply to change the original round winding wire into a winding wire with a flat rectangular cross section. This has many advantages, for example, lines can be closely attached to each other, which improves the slot full rate and brings about the improvement of the overall power density of the motor. It can be understood that in the same refrigerator, you must pack more Wangzai milk in square cartons than in round cans, so that your refrigerator utilization rate will be higher.

For heat dissipation, the larger the cross-sectional area of the flat wire in the same space, the smaller the resistance, and the less the heat generated. In addition, the flat wire has a larger heat dissipation contact surface, which can achieve excellent heat dissipation effect with oil cooling. This is easier to understand, and your cooking is also cut into squares as much as possible, rather than columns, because the contact area is larger, which is conducive to heat conduction.

In addition to the hardware, Zhiji L7′ s motor cooling is also equipped with a thermal management system, which intelligently controls the electronic oil pump through algorithms, and sprays wherever it is too hot. Because the local temperature of the motor will be different under different working conditions, with the algorithm blessing, the heat dissipation can be done more accurately.

Why does Zhiji L7 have to work hard to maximize heat dissipation? Because Zhiji wants too much, he wants small size, high power, good performance, good HVH and low energy consumption.

Fortunately, although the design requirements are harsh, the engineers still meet them one by one. The high-efficiency and high-power permanent magnet synchronous motor mounted on the rear axle of Zhiji L7 solves the heat dissipation problem, achieves the same high performance as asynchronous induction motor, and gives full play to the advantages of small size, good NVH and low energy consumption of permanent magnet synchronous motor.

Thanks to this design, Zhiji L7 can not only achieve dual-motor four-wheel drive, but also break 100 in 3.87 seconds. It can also keep the front of the car in a low posture, and achieve an ultra-low drag coefficient of 0.21Cd. At the same time, with the mute design, the mute level is 3~6dB ahead of the industry.

The braking distance of 32.69 meters is largely due to the customized bembo braking system, including high-performance four-piston all-aluminum calipers and customized large-size high-performance brake discs. Many models only use brembo’s calipers and don’t buy brake discs. They also use brembo to support the scene, and there is little "Ao Bai" like Zhiji L7.

The size of the high-performance ventilation disc of Zhiji L7 is 365mm before and 356mm after, which has reached the level of a million-class performance vehicle. The larger braking friction area can bring better braking response and extremely low thermal attenuation.

In addition to performance, Zhiji L7 also gives consideration to energy efficiency. Zhiji L7 also uses the Onebox fully decoupled brake control system provided by Continental. At present, the mainstream scheme on the market is Twobox system, and the mechanical braking and regenerative braking can’t be decoupled. The intuitive feeling is that when the assisted driving is enabled, the ACC system controls the acceleration and deceleration, and your brake pedal will follow. If the AEB system is enabled, it just happens that your foot is under the brake pedal, and you will probably go to the hospital to hang the orthopedics.

The influence of Twobox system on energy consumption lies in that when you step on the brake, mechanical braking will definitely step in and consume part of kinetic energy, while the rest will flow into the kinetic energy recovery system, and the recovery efficiency is only 60%-70%. Onebox fully decoupled braking control system, when stepping on the brake, can completely rely on kinetic energy recovery to achieve deceleration when the deceleration is less than 0.3 g, and the mechanical braking part will only intervene when it exceeds 0.3 g, so that 100% kinetic energy can be recovered, and it can be called Lu Hua peanut oil-squeezing expert in kinetic energy recovery field. In addition, the Onebox fully decoupled brake control system can realize more flexible adjustment of the brake pedal and provide redundant braking for high-level intelligent driving.

As said in the video, Zhiji L7 reveals an ultimate pursuit of perfection, which is very difficult for such a complex product as intelligent electric vehicle.

The high-level assisted driving realized by the large computing chip and lidar, the liftable screen and 22 speakers create an intelligent cockpit with the ultimate sense of science and technology, and the driving performance that can be rushed out, braked firmly and manipulated flexibly. Zhiji’s pursuit for the ultimate is far more than that.

The paranoid pursuit of perfect quality can promote the perfect integration of scientific and technological progress and user experience. Perfection is difficult, but we can see that Zhizhi is already on the way to perfection.