Mazda CX-7 is the product of a new platform that delivers a vehicle base large enough to accommodate five people and their luggage in comfort, while balancing this with chassis dimensions that deliver Zoom-Zoom handling. The Mazda CX-7 is 85 mm shorter than the Mazda6 MPS (4,680 mm versus 4,765 mm) but has a longer wheelbase (2,750 mm versus 2,675 mm) and is wider by 90 mm (1,870 mm versus 1,780 mm) which delivers great driving stability and translates into SUV roominess and comfort on the inside. The wheels of the Mazda CX-7 are placed at the extreme corners of the vehicle which allowed designers to give the Mazda CX-7 its sporty, aerodynamic design.

Local Reinforcements – Enhanced Body Rigidity
This new platform is enhanced by chassis and suspension systems that deliver outstanding performance feel, with precise steering, handling stability and control. Mazda CX-7’s bodyshell is a paragon of strength and stiffness, with optimised local and overall rigidity. During initial chassis development, CAE methods were used to identify local areas of the bodyshell most likely to flex or deform under extreme driving conditions. These areas were then strengthened with reinforcements designed to keep any additional weight to the minimum.

The rear lamp apertures and the roof rail inner pressings, where they meet the C-pillars were strengthened, as well as the tailgate aperture and the suspension mounting points. An additional joint was added to the side sill, and the cross member sheet attachment area was reinforced. The front cross member and the three transmission tunnel members are pressed from thicker steel to enhance both torsional and flexural rigidity and deliver handling which meets the demands of sporty-minded European customers.

Mazda’s CAE Technology – Optimising Body Strength, Aerodynamics and NVH
Zero-prototype development for the Mazda CX-7 was employed using the latest computer-aided engineering (CAE) technology to create a bodyshell design with optimised handling stability, crash safety and NVH“, explains programme manager Masashi Ohtsuka.

The number of vehicle elements examined by the CAE process was expanded to 363, some of them examined for the first time in vehicle development. Instead of following the conventional process of assessing the car body’s rigidity as a single structure, CAE engineers analyzed each part of the body as a single entity. Key areas – like side sill sections and Seat mounting points – were identified and reinforced.

This enabled engineers to optimise body rigidity for improved handling stability and aerodynamic performance, vital, considering it has a high-performance DISI engine, and crash safety. NVH performance was also optimised by initiating a complete vehicle system analysis that assessed the vibration characteristics of every part of the vehicle, from the front frame to the structure of the panels, to lower cabin noise and create a high-quality ambience inside CX-7 while driving under the widest variety of road conditions.

Suspension
Mazda CX-7 employs a MacPherson strut front suspension tuned to give high rigidity for predictable handling, minimal noise and great driving comfort. The system uses ball-type struts with low friction bearings, strong lateral force control springs, along with six rubber mounting points, for smooth steering feel and good ride comfort. An enlarged castor angle is also used to optimise straight-line stability, while delivering excellent road feedback and grip when cornering.

European Chassis Tuning
In Europe, customers have high expectations when it comes to on-road attributes. To get the most out of the slightly higher power and torque of the European version of the 2.3-litre DISI turbo petrol, members of both Mazda Japan and Mazda’s European R & D Centre in Oberursel, Germanywere given the task of tuning Mazda CX-7’s overall driving performance to meet European driving needs.

The team spent weeks testing the car at Nürburgring’s ‘green hell’ and on German Autobahns to identify where the chassis could be enhanced to deliver this. The result was the introduction of special body reinforcements, suspension enhancements, special tyres and steering settings. These chassis enhancements mean the CX-7 delivers an ideal combination of driving comfort with excellent straight-line stability, superior road hold and steering feedback.

The multi-link rear suspension is designed to ensure the wheels suffer minimal camber change and maintain their near-vertical position even when cornering hard, which is vital to a high‑torque, high-performance All-Wheel Drivevehicle like this. For excellent steering stability, the rear bush structure and location were optimised for good lateral toe change, while the position of the links ensures optimal camber control. For the European CX-7, which has even more power, the pull bars linking the rear suspension to the body adopt a different layout to insure predictable handling and even more precise vehicle reaction to steering input.

The rear coil springs and dampers are separated, with the springs placed under the floor so that friction generated by the dampers is reduced, resulting in smooth damping force on bumpy roads. This layout, which is similar to Mazda5, results in minimal intrusion into the vehicle, with maximum width between the wheel housings, and a spacious, flexible, flat-floored cargo area.

Dependable Traction – Mazda’s Active Torque-Split All-Wheel Drive
The fully independent suspension is complemented by Mazda’s unique Active Torque‑Split all-wheel drive system which ensures that the CX-7’s 380 Nm of maximum torque can be exploited in a smooth and controllable way. Using high-tech sensor technology, the All-Wheel Drive monitors the CX-7’s steering angle, yaw rate, wheel speed, lateral G-force and throttle-valve position, to optimise in real time the vehicle’s road hold whatever the surface and driving conditions.

The vehicle’s all-wheel drive control module then distributes torque between the front and rear axles using an electronically-controlled active-torque coupling mounted in front of the rear differential. The system distributes power between the axles (100/0 per cent to 50/50 per cent front/rear) for just the right amount of torque in every driving situation.