SKYACTIV Chasis

Like with other SKYACTIV technologies, Mazda’s chassis developers were also faced with conflicting goals: deliver extraordinary agility and a feeling of “oneness” between car and driver, ensure high-speed stability, and offer the best possible ride comfort. However, enhancing steering agility, especially at low and mid-range speeds, can negatively affect high-speed handling and stability in general. And such agility and nimble responsiveness can get in the way of ride comfort. On top of all this, developers were looking to significantly reduce the weight of the chassis. Mazda engineers managed to achieve all these goals in the SKYACTIV-Chassis, taking a unique approach to resolve the conflicts.

Reconciling low and medium-speed agility with high-speed stability

The first challenge was to ensure high-speed stability from a chassis that also delivered precise handling at low and mid-range speeds.

Mazda therefore developed a new electric power steering system that enhances the driving experience by providing an immediate response to the driver right from very low speeds. But such nimbleness could make the vehicle react over-sensitively at higher speeds. This is where engineers re-examined the rear suspension’s geometry. Suspension links were optimised and rear-wheel grip enhanced to reduce yaw gain (or ease of turning). Meanwhile, a higher steering gear ratio (for more direct steering) was adopted, increasing yaw gain to maintain nimble steering at lower speeds. The vehicle is thus both agile and stable, and the driver enjoys the best of both worlds at any given speed.

The firm high-speed steering feel is reinforced by increasing the caster angle — and therefore caster trail — on the front wheels (see illustration), which enhances the steering’s self-aligning torque. Power steering assistance is then increased at lower speeds to ease steering and give it the desirably lighter feeling at such velocities. As a result, the new generation of Mazda steers smoothly and securely in all situations.

Reconciling low and medium-speed agility with superior ride comfort

As the “interface” between the platform and the wheels, the suspension is essential to a vehicle’s handling. The arrangement and structure of the suspension determine the precision with which a car steers. They also influence ride comfort. Therefore, the second great challenge for Mazda developers was to optimise this architecture.

The rear suspension proved vital when trying to achieve the best possible balance between agility and ride comfort. The aim was to improve handling without stiffening springs or shock absorbers.

First of all, to enhance the operational efficiency of the dampers, the mounts were set at a position enabling a greater lever ratio. The damping force and rigidity of the top mount rubber were thus reinforced, reducing their impact on ride comfort. The rear suspension trailing link attachment position was also shifted upwards, thereby adjusting the direction of movement of the trailing links to more easily absorb longitudinal impact shocks from the road. This also improves ride comfort, while at the same time preventing the rear of the vehicle from rising. And that delivers increased stability when braking, which helps reduce stopping distance.

Reconciling reduced weight with increased rigidity 

The chassis weighs 14% less than the current version. Yet it is still more rigid. And that was chassis breakthrough number three.

Engineers placed a special focus on the chassis cross members in their efforts to achieve the ambitious weight reduction objectives. After defining their functional requirements, CAE (computer-aided engineering) technology was used to design a conceptual model and coordinate the optimum structure into the overall vehicle package.

The centre section in the front of the car was extended and the longitudinal offset of the lower arm attachment position was reduced.

In the rear, meanwhile, the longitudinal span of the cross member was extended and the longitudinal offset of the lateral link attachment position reduced. Welding flanges were also removed from the front and the rear to enhance the coupling rigidity of the welded sections. All these measures considerably enhance overall stiffness in a lighter chassis.

This is how intelligent solution led to numerous improvements that together make up the SKYACTIV-Chasis. Engineeers have achieved what they set out to deliver. Namely, the driving fun, safety, ride cofort, agility and stability worthy of a new-generation Mazda

SKYACTIV Body

Talk about the body, excellent rigidity supporting Mazda's fun-to-drive feel, with a lightweight body to achieve outstanding crash safety performance. SKYACTIV body feature : 

• High rigidity and lightness (8% lighter, 30% more rigid)
• Crash safety performance that meets the top criteria for crash safety assesment in all market.

Ideal body structure

In terms of structure, Mazda revise the basic principe. For the basic framework, they adopted the concepts of 'straightening' and a 'continuos framework' in which each section functions in a coordinate manner with the other section of the framework. Mazda ensure that the structure disperses force widely throughout the entire framework, rather than receiving the force on only specific sections of the vehicle. That was all important thing that need to be consider when Mazda creating a light body yet strong framework.

Straight and continous basic framework

For the underbody area, curves were removed as much as possible to create a straight frame in a continuous configuration from the front to the rear. For sections of the frame that still require some curvature, Mazda implemented continuous bonding with the horizontal frame to make the structure a closed section, thus contributing significantly to weight reduction while at the same time achieving rigidity.

The upperbody also functions as a constituent part of the continuously bonded framework. Specifically, the suspension mounting positions at the front and rear of the upperbody are directly bonded with the underbody framework as a “dual brace”. In addition, by creating four ring structures for the upperbody that includes the roof rail and B-pillar, and the entire reinforcement area of the underbody, the overall rigidity of the body has been further enhanced.

Multi-load path structure

To improve crash safety performance, Mazda adopted a multi-load path structure. The structure efficiently absorbs the load at the time of a crash by dispersing it in multiple directions. For example, energy received when a frontal collision occurs is absorbed by being dispersed along three continuous routes (paths): from the front frame to the B-frame, from the front frame to the side of the body, and from the front frame to the A-pillar. In particular, the upper branch frame, which diverts the load to the A-pillar, is a multi-functional part that also works to cancel the upward motion of the front frame. To create this kind of path, parts such as door hinges, which do not normally play a role in absorbing shock, are important elements in the design. Naturally, the multi-load path structure is adopted for lateral collisions and rear collisions as well to function in the same way, thus greatly improving safety performance.

The multi-load path approach was also adopted for individual parts. Mazda focused on directing the crash energy mainly along the ridge lines of the parts, molding the front tip of the front frame into a cross shape. In a conventional square section, there are four ridge lines, but when a cross is created there are twelve ridge lines, and the shock is dispersed more widely. By doing so, the energy is then absorbed more efficiently, the space in the engine room is more effectively used, and there is also greater freedom in exterior design.

Engineering process

To create a circular structure for the reinforcement, weld bonding was used for the roof rail section. Before SKYACTIV this structure was separated from the rear frame due to the body assembly process. To bond this section directly, Mazda has adopted a method whereby the parts are bonded together in advance using the weld bonding method and then sent on to the assembly process as a bonded unit. By adopting this method, Mazda have achieved continuous bonding, at the same time greatly increasing the number of spot weld points, which contribute to the excellent body rigidity.

In terms of materials, Mazda have greatly increased their use of high-tensile steel, which is lightweight and has excellent strength and rigidity. In the new body , high-tensile steel, the thinnest in its class which is CD-segment car (Mazda6 class), is used for most of the main parts, and this has resulted in significant weight reduction benefits.

What is SKYACTIV?

Mazda 6 with SKYACTIV Technology

Over the year car manufacturer try to improved their car  that makes no compromises between fuel economy or performance. For an example, with the hybrid technology nowaday, the efficiency do come better in term of fuel but what about the performance? When it comes to mazda, they achieved it with the SKYACTIV Technology. The SKYACTIV Technology make the car efficient, powerful and also feature the world's best compression ratio in a mass production model, outstanding fuel economy and low emissions with no compromise on performane.

New transmissions and a lightweight construction also mean that  Mazda models are as responsive as a sports car but with the comfort of a high-class saloon car. All thanks to Mazda's ground-breaking new SKYACTIV Technology.