Easy Car Original "All children are born to know it. Only a few people grow up remembering it. Only one car company has never forgotten it. In adult language, it is used to express the pleasure and release brought about by extreme movement. In reality, however, only the kids really understand it, simply saying, "Go play Zoom-Zoom." And we practice it every day. That's why we can build the kind of car that's in front of you at this moment. Zoom-Zoom！ Did we wake it up from your heart today? The passage is quoted from the title page of the Owner's Manual for the Mazda MX-5. So what is Zoom-Zoom? Today, take my own MX-5 as an example, through the chassis analysis, take you to understand the spiritual essence of Mazda Zoom-Zoom.
· Static introduction
My MX-5 is a parallel imported ink gauge 2018 2.0MT i Sport version, model code: ND5C. Different from the MX-5 RF (NDERC) introduced on the official website, the two biggest differences are that the first is equipped with a 6-speed manual transmission, and the second is a soft-top convertible structure.
In terms of appearance, compared to the cute and cute image of the previous three generations of MX-5, the ND's fierce "small eyes" always remind me of angry birds. The extended front and rear fenders give it the visual effect of being born with a self-ampherent body. The vehicle shape does not have too many complex hard line designs, but through the curved surface of the soft line bend, the body form full of power is created, which fully interprets the core concept of soul designless is more.
The long nose, short front overhang, long wheelbase, and cockpit proximity to the rear wheels are design features that bring out the Roadster's temperament. Compared with the RF version, the soft-topped version can completely store the canopy into the body, and the body line is more elegant and flowing after the canopy is opened.
It is worth mentioning that the soft top of the MX-5 has been manually opened and closed since the first generation of models. The roof structure is simple, light, no complex electric mechanism, the action of the switch canopy is not more than 3 seconds, not limited by the speed, you can enjoy the blue sky and white clouds and the breeze anytime and anywhere, which is one of the unique secrets that the MX-5 can sell well for more than thirty years.
Enter the car, do not have too many expectations of the MX-5, the interior materials are hard plastic, after all, its price in North America is also comparable to the Axela. Fortunately, Mazda's designers put all their limited budgets on the cutting edge, and regardless of texture, the design and layout of this interior are still very online, which complements the appearance.
· dynamical system
In terms of power, the MX-5 ND is equipped with a 2.0L Chuangchi Blue Sky engine, with a maximum power of 116 kW and a maximum torque of 200 N·m, and adopts rear-wheel drive with a front-center layout. Note that the front-center layout is being said here, not the front-facing layout, as the MX-5's engine front section almost overlaps the vehicle's front axle, and the engine mass center is behind the front axle, making it strictly a rare front-center layout. Models that also have such a layout include the Honda S2000, Mercedes-Benz SLR, Dodge Viper and Corvette, among others.
Equipped with the engine is a 6-speed manual transmission, this gearbox code-named M66M-D is a brand new product specially developed for ND. Next, a brief introduction to the design characteristics of this gearbox, the reason why the manual transmission of the NC is not followed is for the sake of lightweighting, and the entire drivetrain of the ND weighs only 82kg. The gearbox concentrates the forks and synchronizers that are routinely distributed on the spindle and countershafts on the spindle, simplifying the structure and reducing the size of the gearbox.
In addition, this gearbox does not have overspeed gear, the highest gear speed ratio is 1:1, for direct gear, the engine power is directly toothed by the input shaft and the output shaft, and is delivered to the rear differential by turning the shaft, which not only improves the power response, but also reduces a set of transmission gears and reduces the weight.
Another advantage of this design is that it eliminates the shift reversal mechanism of the 6-speed transmission, because we are now accustomed to pushing the hook forward in odd gear (1/3/5 gear), the lower end of the gear is moved backwards, and the even speed gear (2/4/6 gear) is reversed, but due to the gear arrangement of the longitudinal 6-speed manual transmission, the synchronizer needs to move forward to enter the corresponding odd gear, so there needs to be a reversal mechanism between the gear handle and the gearbox to complete this operation. However, the MX-5's gearbox 6th gearbox does not have transmission gears, so the gear arrangement is the same as that of the 5-speed gearbox, so it can eliminate this reversing mechanism, further simplify the structure, reduce weight, and also have a more direct shift feel.
· Chassis construction
As the saying goes, "rather light 10 kg, not 10 horsepower", lightweight design is implemented in the entire MX-5, the soft top manual version of the curb weight is only 1058kg, the Japanese gauge 1.5 version is as low as 990kg. In order to maintain rigidity while reducing the weight of the vehicle, the MX5 ND makes extensive use of high-strength steels and aluminum alloys above 780Mpa. The body coverings, with the exception of the rear fenders, are all made of aluminum alloy. Suspension linkages, steering knuckles, engine under guard plates, ground structural parts, front and rear anti-collision beams, and anti-roll frame assemblies are also made of aluminum alloy.
The middle of the chassis is equipped with two reinforcements are made of aluminum alloy, of which the reinforcement issued by the gearbox is an exclusive accessory for the manual transmission version, and the automatic transmission version cannot be installed due to the size of the transmission. The rear X-shaped reinforcement has been around since the NC, and the triangular opening in the middle is a stealing light design.
Around the drive shaft is an aluminium alloy longitudinal reinforcement with a stealing design, which connects the gearbox and rear differential at each end. The reinforcement, called PPF (Power Plant Frame), can be seen as a separate stringer to increase body rigidity, and is a very important part for the MX5, which has been around since the beginning of the original NA model and continues to be used today.
The front and rear subframes are made of high-strength steel with a punched light design. Compared with the NC rectangular rear subframe, the new design can not only improve the rigidity of the rear axle, but also ensure that the impact force is better absorbed by the body, but also reduces the material used and reduces the weight.
· Suspension system
In terms of suspension, the MX-5 ND adopts a combination of front double wishbone independent suspension and rear multi-link independent suspension, which is more stable for wheel control and is one of the most common forms in sports cars.
The structural characteristics of the double wishbone independent suspension are that the steering knuckle is connected by the upper and lower control arms, compared to the McPherson suspension, the presence of the upper control arm makes the lateral rigidity better, the structural stability is higher, and the geometric changes in the suspension work can be more adapted to the road surface, maintaining the tire touch area, so as to have a stable grip performance. In addition, compared with the previous generation of cars, ND strengthens the setting of the negative inclination angle of the main pin of the steering knuckle and the built-in amount of the negative main pin, and the effect is that when the current wheel is braked on the road with different friction coefficients, the wheel on the high friction side will be slightly deflected to the low friction side, thereby correcting the vehicle misalignment.
The front suspension's upper and lower control arms and steering knuckles are made of aluminium. The upper control is installed in the lower position of the body, reducing the center of gravity of the body, while also reducing the volume of the knuckle and reducing its mass. The lower control arm is equipped with a slitting light design, which further implements the lightweight design concept.
The rear multi-link independent suspension is composed of four directional control arms and a longitudinal control arm, and the control arms are composed of tubular steel, which is a very typical Japanese "chopsticks" suspension. The housing is very compact and made of aluminium alloy. The rear suspension of the MX-5 in the NA and NB models adopts the form of double wishbones, and the multi-link form is changed from NC, but it can still be seen from the linkage structure layout that it tends to be A-shaped, that is to say, its dynamic performance will be close to the characteristics of double wishbones.
The longer rear lower control arm primarily manages the rear harness angle. The shorter front and lower control arms are mounted under the housing and control the camber of the rear wheels, while it also works with the longitudinal control arms to guide the wheel's jump angle and suppress vehicle roll.
The rear anti-roll bar of the MX-5 ND is very interesting, basically the smallest of all the cars I have ever seen, which is deliberately done by Mazda, although the thinner anti-roll bar will reduce the limits of the vehicle, but it can allow the driver to experience more of the driving pleasure of the vehicle's center of gravity shift. It can be seen that its positioning is Fun Car, not Track Car.
The lower control arm of the front and rear suspension of the MX-5 and the subframe connection are made of eccentric bolts, the advantage of this design is that the inclination angle and vertical angle can be adjusted by the eccentric bolts, as well as the wheelbase of the same-sided wheels, but it should be noted that such a setting is relatively high for the machine that does four-wheel positioning, and it is necessary to calibrate the wheelbase of the same-sided wheels before each adjustment positioning, and then adjust other parameters, otherwise it is difficult to adjust the positioning data to a reasonable range.
· Driving experience
Mazda's emphasis on "centaur unity" is a unique driving sensation, and this feeling is very intuitively displayed in the MX-5 ND. First of all, the small body size and the 50:50 front and rear weight distribution can make you feel that the four wheels of the vehicle are the extension of your limbs while driving.
The second is that its very low sitting posture and almost zero sound insulation will increase the speed of the car from the visual and auditory point of view. I remember driving the MX-5 for the first time, I drove 80km/h on the elevated road, but the sensory speed was already over 100km/h. This is the same as the go-kart, although the speed is usually 20-30km/h, but we still feel very exciting to drive.
Unlike our general concept of steering, the heavier the feel of steering, the more controlled the MX-5 ND's steering feel is very light, light to the center of the steering and a little bit of vacancy, but the actual driving is very precise, is the feeling of doing something easily with half the effort.
In addition, there is its original vibration damping adjustment, which plays a role in establishing the steering feel. Many people, including some professional racing drivers, have complained that the MX-5's roll came very early, and the amplitude was very large, and there was a roll when the direction was slightly hit, which was tantamount to amplifying the steering response.
When I first drove this car, I also felt that this adjustment was not right, until I once drove it to run Siming Mountain, continuously bending on the mountain road, the vehicle kept rolling back and forth, but the wheels always firmly grasped the ground, and then I finally understood Mazda's good intentions. That being said, this tuning of the MX-5 will scare people to death before rolling over, and the limits of the vehicle are much higher than you think.
I have now changed a set of grinding tooth shock absorbers because of the body posture, and the roll is much smaller than the original factory, and the limit is higher. But from beginning to end, I think that the driving pleasure is far less than the original factory vibration reduction, which is also the first time that I feel that "four flat and eight stable" is not as good as "people on horseback".
Editor's comments: When compiling the data to write this article, the word I used the most was "lightweight", the appearance rate of these three words was so high that I even once suspected that my thesaurus was not rich enough, but this was indeed the landing result of the design goal "return to NA" proposed by MX-5 ND at the beginning of the project. "Return to NA" is not only to reduce the weight of the body and reduce the body size, but more importantly, to return the ND to the origin of "human and horse integration". It's a car that makes you smile involuntarily when driving, and even though I've owned it for more than 3 years, I still feel this way every time I drive it. It's like the phrase "Go play Zoom-Zoom," because I believe every kid has a smile on their face when they say it.
Note: Some of the pictures in this article come from the Internet and the official.