[YesAuto chassis analysis] Dongfeng Nissan LANNIA Bluebird will be officially launched on October 26. This new car has attracted the attention of many young consumers with its unique and individual appearance. The data of competing cars in the backstage of Autohome shows that netizens who follow LANNIA Bluebird will also pay close attention to FAW Toyota Corolla and Mazda 3 Axela. Today we are not going to compare the appearance, interior and power performance of these three cars. What we want to see is the difference between the three cars in terms of chassis structure and materials? Without further ado, let's take a closer look through the comparison of real shots.
■ Reading tips
■ Models we conducted chassis analysis and comparison
The models we used to shoot the chassis include the 2016 LANNIA Bluebird 1.6L CVT high-energy version, the 2014 Corolla 1.8L CVT high version, and the 2014 Mazda 3 Axela Angkesaila sedan 1.5L automatic premium model. In terms of model year and configuration, there may be differences between different models, please forgive me.
■ Chassis panorama
This dismantling and comparison, the focus is mainly on the front suspension, rear suspension and chassis details. The front suspensions of these three models are all Macpherson-style independent suspensions. Toyota Corolla and Nissan LANNIA Bluebird rear suspensions use torsion beam non-independent suspensions, while Mazda 3 Axela Angkesaila uses four-link independent suspensions. What are the differences between these three cars in terms of suspension structure and chassis workmanship? Let us verify the truth through real shot comparison.
■ Front suspension comparison
In the market segment of compact cars, Macpherson-style independent front suspensions are widely used. The suspension of this structure has the characteristics of simple structure, small space occupation, light weight and low manufacturing cost. In terms of materials, the three use steel materials consistently.
● The structure of the front suspension
● Details of the front suspension
The front suspension of LANNIA Bluebird and Angkesaila uses a ball joint integrated with the lower arm. Corolla uses an independent ball head that can be detached separately. The independent ball head can be replaced separately after being damaged, without the need to replace the entire lower control arm, which can reduce the maintenance cost of the vehicle. The lower control arm of the front suspension of Corolla and Angkersela adopts an opening design that can reduce the mass of the lower control arm. The reduction in the mass of the control arm is conducive to reducing the unsprung mass and improving the response performance of the suspension.
● Front brake system
The front brake systems of the three cars all use a single-piston floating caliper and a ventilated brake disc configuration. The same configuration is widely used in this class of cars.
● Powertrain support
The powertrain support is mainly used to suppress and isolate the vibration of the powertrain, and play a role in preventing the transmission of cavity resonance. The support can solve a variety of noise problems caused by the vibration of the powertrain. Let's take a look at the differences in the structure and layout of the powertrain support of these three cars.
The three cars all use torsion moment support as the powertrain support, but the three powertrain support structures are quite different. The powertrain support of LANNIA Bluebird and Ankerra is located in front of the front subframe, while the powertrain support of Corolla is located above the front subframe. The layout position of the powertrain support is affected by the layout and structure of the powertrain and the subframe. By reasonably arranging the support of the powertrain, the vibration of the powertrain can be blocked to the greatest extent and the NVH performance of the whole vehicle can be improved.
● How to suppress torque steering?
Torque steering refers to the unevenness of the torque transmitted to the wheels on both sides of the vehicle due to the unequal length of the drive shafts on both sides of the vehicle. When the vehicle accelerates rapidly, the torque steering phenomenon is more obvious, and in severe cases it will cause the vehicle to deviate. Let's take a look at the ways in which these three cars suppress the torque steering problem.
In order to alleviate the torque steering problem caused by the unequal length of the left and right half shafts when the vehicle is accelerating rapidly, Corolla and LANNIA Bluebird are equipped with damping blocks on the half shafts. In order to solve the above problems, Angkerra moved the position of the right universal joint to the right (left in the figure), so that the length of the half shafts on both sides tends to be the same, and the problem of torque steering is minimized.
● Front anti-roll bar diameter
● The structure of the subframe
The design of the front subframe shows the characteristics of the vehicle's impact energy absorption and impact force guidance. Let's take a look at the front subframe of these three cars.
All three cars use a MacPherson-style front suspension structure, and the lower control arms are all made of steel. In order to suppress the torque steering problem during rapid acceleration, LANNIA Bluebird and Corolla have added damping blocks on the half shaft. On the other hand, Angkersai moved the right universal joint to the right (left in the figure), so that the length of the left and right half shafts tended to be the same, thereby suppressing the torque steering phenomenon to the greatest extent.
■ Rear suspension comparison
Due to the fierce competition in the compact car market, many manufacturers have brought multi-link independent rear suspensions that can better balance handling and comfort to this market segment. The rear suspension of Angkesaila uses a multi-link independent suspension. The LANNIA Bluebird and Corolla use the torsion beam non-independent rear suspension that is more common in compact cars.
● The structure of the rear suspension
The position of the torsion beam of the torsion beam non-independent suspension has a direct effect on the characteristics of the rear suspension. The multi-link independent suspension, with more control arms, can more accurately control the four-wheel positioning parameters. When the vehicle is moving, especially during turning, it can control the wheels to maintain a proper posture, thereby making the tire tread better. Good contact with the ground to ensure a good grip.
The distance between the pivot and the wheel axis of the LANNIA Bluebird and Corolla torsion beam rear suspension is relatively long, which is an adjustment that emphasizes comfort. The four-link independent rear suspension adopted by Angkersela, the longitudinal swing arm mainly bears the longitudinal force, the other three lateral control arms mainly bear the lateral force, and all the control arms jointly position the wheels.
● Arrangement of springs and shock absorbers
The arrangement of springs and shock absorbers reflects the adjustment orientation of the vehicle chassis to a certain extent. For example, the use of a long-stroke shock absorber can increase the shock absorber's shock absorption stroke, which is helpful to improve the ride comfort of the vehicle. However, long-stroke shock absorbers will encroach on more space in the car, which poses a problem for development and design.
The three cars all use column spring separation damping design, and the fixed point on the rear shock absorber is located inside the wheel arch, which is beneficial to increase the rear space of the vehicle. At the same time, the use of long-stroke shock absorbers also improves the ride comfort of the vehicle to a certain extent.
● Torsion beam/rear anti-roll bar
● Rear brake system
The rear braking systems of the three cars all use a single-piston floating caliper design. At the same time, all models of these three cars are equipped with traditional cable-type handbrakes.
● Rear anti-roll bar/stabilizer bar diameter
Although the rear suspension structures of these three cars are not the same, the column spring separation damping design is also adopted, and the fixed point on the rear shock absorber is located inside the wheel arch, which is conducive to increasing the rear space inside the car. At the same time, the use of long-stroke shock absorbers also improves the ride comfort of the vehicle to a certain extent.
■ Comparison of other details
From the previous article, we can see that the suspension of the three cars has some similarities in structure, but there are many differences in the details. Let's take a look at the differences between these three cars in terms of chassis details.
● Details of the bottom of the engine
Of these three models, only Angkerra has a resin-made engine lower guard plate at the bottom of the engine. The lower guard plate is relatively straight, which is beneficial to improve the aerodynamic performance of the bottom of the vehicle. LANNIA Bluebird and Corolla are not equipped with an engine bottom guard. In daily use, there is a hidden danger of damage to the powertrain due to foreign objects on the road. If your vehicle often drives on poor roads, you can consider installing a lower engine guard to reduce the chance of damage.
● Details of the underbody
Among these three models, only Angkerra has a resin underbody guard plate on the underside of the car. In addition to playing a protective role, the flat underbody guard can also improve the aerodynamic performance of the bottom of the vehicle. The underbody protection of the other two cars is achieved by spraying anti-stone strike coating. Reinforcing parts are installed on the bottom of the three cars to improve the torsional rigidity of the car.
● Details of the bottom of the spare tire groove
Corolla’s spare tire slot is provided with a resin guard plate, which can divert the airflow flowing through the bottom of the vehicle body, allowing it to pass more quickly and smoothly. The LANNIA Bluebird's spare tire slot is not covered with any guard plate, nor is it sprayed with anti-stone coating. Due to the independent rear suspension, the rear sub-frame and the rear muffler occupy most of the area under the spare tire groove. If you want to not affect the luggage compartment space, you must reduce the depth of the spare tire groove and use more volume. Small non-full-size spare tire. From here we can also see that the independent rear suspension occupies more chassis space than the torsion beam non-independent rear suspension.
● Wheel arch processing details
The wheel arches of these three models are sprayed with a coating for protection. Corolla and Onksera both have guards for the front and rear wheel arches, while LANNIA Bluebird only has guards for the front wheel arches. Compared with the resin protection board, the glass fiber protection board has better sound insulation performance.
● Tire details
In terms of tires, LANNIA Bluebird and Corolla both use Bridgestone's Terran series tires that focus on comfort. On the other hand, Angkerra uses Goodyear Ancheng series tires, which focus on wet grip performance and provide better safety performance when driving in rainy weather.
● Spare tire details
In terms of spare tires, among the three cars, only Corolla is equipped with a full-size spare tire, and the spare tire is matched with the same style of aluminum alloy wheels as the original car. LANNIA Bluebird and Angkersela are equipped with non-full-size spare tires, and the spare tires are matched with steel wheels.
LANNIA Bluebird and Corolla use a front MacPherson rear torsion beam suspension collocation, and the adjustment focuses on comfort. Angkesaila uses the front and rear Macpherson multi-link suspension collocation, focusing on the balance of comfort and handling. From the actual shooting, we can also understand that the multi-link independent rear suspension occupies more space than the torsion beam non-independent rear suspension, which affects the size of the rear compartment to a certain extent. In addition to the difference in suspension structure, the three cars have big differences in terms of chassis protection. The bottom of the engine and the underside of the car are covered with resin protective panels, which not only improve the protection of the vehicle chassis, but also improve the aerodynamic performance of the vehicle. However, LANNIA Bluebird and Corolla do not use guard plates to cover the above two parts, and the chassis protection is mainly realized by anti-stone coating. Corolla is equipped with a guard plate under the spare tire groove, which can improve the aerodynamic performance of the vehicle to a certain extent. (Photo/text car home Chang Qinglin photo car home Tang Dynasty)