Text: Xu Caiyu
Editor|Li Qin
In the decision to buy a car, the chassis seems to be the most inconspicuous factor, and the space/appearance/sound/configuration are more attractive to consumers. But on the other hand, the chassis is an important criterion for whether the affordable car can stand the test of time, the Volkswagen old Jetta listed in China in the 90s, because of the characteristics of stable driving and control, strong adaptability to road conditions and other characteristics to the top of the word of mouth, these driving advantages are closely related to the quality of the chassis.
German cars have always been the face of chassis quality, Volkswagen is known for its robustness, and Mercedes-Benz is known for its orderliness. Observing its various levels of cars, you will find that the chassis flatness and thermal insulation design can be called a textbook operation, but Mercedes-Benz never "heaps configuration": the A and B-class front overhangs use MacPherson structure, the C-class adopts multi-link type, and the E-class uses a double wishbone type, which is the standard material in the product rating. In the case of almost "no cost performance", the experience is not reduced, and the tuning method is the source of its confidence.
The poor texture of the chassis has always been the shortcoming of domestic cars, and very few domestic cars can get the evaluation of "good driving" after years of use by car owners, and more often they are eliminated and replaced with joint ventures or imported cars. From fuel vehicles to new energy vehicles, the situation has improved, but it has not changed.
Tesla vehicle word-of-mouth score
Although the evergreens Tesla Model 3 and Model Y on the tram list are called "rough houses", they still dominate the list for several years, and domestic cars with volume configuration and volume performance have failed to move their share. In addition to "simple", the most received evaluation is that the chassis is well tuned, powerful, well handled, and responsive. The use of vehicles is inseparable from driving, and the level of chassis directly affects the reputation of the vehicle, and the reputation of the vehicle is closely related to the sales volume, and the AVATR 11 with full configuration is a typical case.
AVATR 11's materials overflow the luxury of the screen, similar to the Mercedes-Benz E-class, the double-ball wishbone front overhang and four-link rear overhang, the front and rear subframes are all aluminum full-frame structure, but the final effect is not satisfactory, the main technology is comfortable and luxurious, but the vehicle shock absorption effect is unsatisfactory, the driver's seat has a strong sense of road, the rear ride experience has a "bumpy feeling", and there are high-speed fluttering, cornering and other problems. The monthly sales of vehicles of the same level of friends have exceeded 5,000 or even 10,000, while the monthly sales data of AVATR 11 has been hovering at 1,000-2,000 units.
The chassis with more than 90 points will be praised as long as you step on the pedal, but most car buyers have a perception of the chassis and are not so delicate, as long as it is not too bad, there is no gap between the 60-90 points chassis on the consumer side. But how to quickly perceive the quality of the chassis?
Schematic diagram of the car
The support should be stable and the shock should be well filtered
Stability is one of the core indicators to measure the quality of a vehicle. A car with a compact chassis will have a very strong grip and will give the driver a lot of confidence when crossing high-speed ramps and making a quick U-turn. ZEEKR's 001 model is a typical top student.
The width of the car is 1999mm, the tire width is 255mm, and the wider ground contact area than the same level of sedan brings stronger lateral support. On the track, the steering angle and speed are larger, and the centripetal force is full, and the driver's experience will be more obvious.
SUV models, on the other hand, are inherently more challenging due to their high body attitude, high ground clearance, and heavy body weight. In an SUV with poor chassis tuning, in a big bend that goes downhill at high speed, a slight acceleration will feel that the right tire is about to leave the ground, and the vigilance of overturning arises spontaneously.
But in fact, as long as the support is not too weak, it can be accepted by consumers. In urban car scenarios, consumers are more concerned about shock filtration, i.e., the comfort and noise level of speed bumps.
ZEEKR 007 real picture
007, which is the same as the 001 division, has made a krypton level of support. In the all-wheel drive version with CDC electromagnetic suspension, bumps caused by speed bumps or smaller uneven road surfaces are filtered cleanly, and the interior comfort is good. Equipped with Huawei Touring chassis Zhijie S7,When frequently passing over speed bumps,What you feel in the car is not "grunt",It's "grunt",It's also eye-catching in sports cars,However, the existence of high-speed throwing and jumping,It also leaves some room for improvement。
The main source of shock filtering comes from the suspension, with air suspension being the best, followed by electromagnetic suspension, and mechanical suspension being weaker. But the material is only the material, many domestic manufacturers are concerned about the shock filtering, forget the feel, blindly filter the road information, so that the driver can not feel the road condition, ups and downs and foreign objects, which explains why some vehicles equipped with air suspension are not easy to drive.
The Mercedes-Benz E-class sedan that only uses the electromagnetic adjustment system is even higher than these models in terms of ride comfort, and in the final analysis, it depends on the manufacturer's methods. While air suspension can absorb more vibrations and is more compatible, the electromagnetic damping system is more responsive to adjustment. The right damping coefficient, combined with a highly matched spring elasticity coefficient, can indeed produce a shock absorption effect comparable to that of an air suspension.
The selection, matching, and feedback of these coefficients to the driver is the reason why the Mercedes-Benz E-Class has a comfortable ride but a sense of handling.
Schematic diagram of a car passing over a speed bump
The steering should be accurate and the brakes should be fierce
Steering is one of the most important sources of driving pleasure, and drivers crave a go-kart-like steering experience. Tesla's Model 3 and Model Y have almost zero negative steering performance, and the sensitive steering is conducive to the driver's grasp of the road and vehicle conditions. On the other hand, a car with a vacant steering position is not "fun" to drive. Generally speaking, a car with a softer chassis will have a slower steering response and is more likely to be out of position, while a car with a hard chassis will be more responsive.
The ordinance stipulates that a steering position within 15 degrees is reasonable, but the driver needs to have a "proper" false position when actually using it. Part of the praise received by the Model 3 facelift comes from the steering, which adds a moderately empty steering to reduce the dizziness of the occupants. Some domestic electric cars, especially SUV models, often receive the evaluation of "driving like driving a boat", taking into account the shock filtering effect and losing the steering feel.
In addition to steering, braking and acceleration are the directions that consumers pay great attention to when test driving electric cars. In the development of electric vehicles, the rapid power response is a major attraction that is different from that of gasoline vehicles, however, the "value" of 000 acceleration is rapidly depreciating today, and it seems that it is not difficult to step into the 3-second club. However, the acceleration time is not equal to the acceleration experience, and at the same level of 3 seconds, the Tesla Model 3 Performance is still the benchmark work of the tram pushing back feeling.
The AVATR 11 with a 0-100km/h time of 3.98s, the ZEEKR 007 with 3.8s, and the Zhijie S7 with 3.3s are observed by PowerOn in the 000 acceleration experience of different models, the instantaneous power/torque and acceleration curves are different. The Model 3 Performance accelerator pedal is responsive and explosive, and the feeling of pushing back is largely derived from the acceleration results in the first second, whether it can accelerate to 30 km/h or 40 km/h in one second. Domestic vehicles of the same class accelerate quickly and are more linear as a whole.
The principle of braking and acceleration is similar, the braking distance is only a reference index in a specific test environment, and the factors that affect the driver's braking confidence are quite comprehensive, such as the friction of the tires and the compactness of the chassis. There are many different ways to accelerate, but the requirements for braking are highly similar:
The basis is that the braking can be stopped, and the instantaneous burst of braking force when the brake pedal is deeply pressed is sufficient; secondly, it is comfortable to pedal, the pedal area is moderate, the braking foot feeling brought by the pedal leverage ratio is in line with human factors engineering, and the brake nod is seriously light or none, which directly affects the daily driving comfort. The car that doesn't stop braking can't be driven, and no one wants to drive the brake if it's uncomfortable, and the braking is one of the few that car companies must have the ability to adjust.
Schematic diagram of a car cornering
Regardless of the change of technology, the driver's expectations for the chassis are highly similar: they want to keep the "feel" from the road to the steering wheel while the shock filtration makes the "butt" comfortable, they want the steering support to be strong without zero roll, the high-speed swing is small but the urban area is not empty, and they want the power to be strong but smooth, and the braking is comfortable and powerful. In this way, consumers' requirements for chassis are actually "unconsciously high", but in the era of fuel vehicles, the average score of the chassis of imported joint venture cars is too high, and the score difference is too small.
Refrigerator color TV sofa is too easy to copy, car companies have begun to emphasize the investment in the chassis, Huawei's self-developed Tuling chassis has been mass-produced, and even the main user of NIO has released an intelligent chassis system. Relying on the high cost performance of stacking materials is only temporary, the price war continues, and some Mercedes-Benz models have begun to reduce the configuration, but the excellent tuning techniques allow it to ensure the car experience. And how will domestic brands deal with it? Solid chassis and serious technology will become the main tone again.