Press Release
Page 1: Focus XR5 Turbo
Page 2: Interior/ExteriorDesign
Page 3: Power for performance
Page 4: Dynamics
Page 5: Safety
Dynamics
The first generation Ford Focus set suspension standards still regarded by many as the benchmark for today's compact car chassis.
"The suspension on this car was so well sorted that no fundamental changes were necessary to incorporate it directly into the new Focus range, or its all-new XR5 derivative," said Ford of Europe C-Car Vehicle Line Director Gunnar Herrmann.
After seven years' experience with the 'Control Blade' independent rear suspension pioneered by the original Focus, the Ford Vehicle Engineering team concentrated on enhancements rather than starting all over again.
In addition, a stiff new front subframe for the new Focus became the foundation for the car's chassis behaviour and underwent extensive tuning for the hot hatch derivative.
"It was crucial for us that the new Focus range maintained its dynamics leadership position. From the outset, the chassis of the new model was engineered to provide very high standards of driving quality, inspired by class-leading dynamics."
Developing the core model into its XR5 performance sibling was a priority as soon as the new Focus engineers were satisfied with their work.
Paul Wijgaerts, Ford TeamRS Vehicle Engineering Manager was the man responsible.
"The new Focus received very good reviews from the press for its fantastic cross between comfort and steering precision; not to mention its driving safety in varying conditions," Wijgaerts said.
"Our task for the XR5, therefore, was to tune the suspension very precisely for even sportier performance and greater agility. However, it was never our goal just to achieve good lap times around the N??????????????????rburgring at the cost of a significant loss in comfort."
Focus XR5 Turbo uses the core model's front axle, which has transverse control arms and MacPherson struts.
The already stiff bodyshell of the new Focus was strengthened further for the XR5 Turbo version, via an extra cross-member running across the bulkhead between the spring strut covers in the engine bay.
Unique springs were developed, and their dimensions calculated so even though the car sits 15 millimetres closer to the road, their travel of around 200 millimetres is not reduced.
Positive spring travel (compression) is slightly decreased and is firmer. Negative spring travel (expansion) is increased by the same amount.
"Since the expansion is greater, the Focus XR5 Turbo's tyres maintain excellent levels of grip over the full extent of the negative jounce.
"What that means for the customer is superb road holding even over poorly maintained roads," Wijgaerts said
The award-winning Control Blade IRS has been fine-tuned for the XR5, using stiffer rubber housings for the lower control arms, while axle geometry has been adjusted to cope with higher lateral forces.
The Focus XR5 Turbo uses the new Electro-Hydraulic Power Assisted Steering system developed for the new Focus range, combining the advantages of a hydraulic system with the adjustment of power steering.
The hydraulic system ensures high levels of driving precision and superior feel and feedback from the road, while the power steering allows lower parking efforts and ease of handling in low speed, urban situations.
Pressure in the system is provided by an electro-motor driven pump that uses vehicle and steering wheel speed inputs to calculate the optimum power adjusted steering support for all conditions.
Wijgaerts explained the power assisted rack and pinion steering's variable turning ratio was made more direct overall to suit the sporty Focus XR5 Turbo.
"The steering is 8 per cent faster acting than regular Focus models to give the XR5 driver more direct feedback back through the steering wheel.
"This set-up gives drivers two reasons to be enthusiastic: in addition to the sheer joy of real precision driving, the Focus XR5 Turbo exhibits sympathetic road manners too."
Wijgaerts explained the steering can also be ?????????????????????????????????fine tuned?????????????????????????????????????? by the driver to suit specific usage.
???????????????????????????????????The computer-controlled electric steering pump has three settings, or maps, which can be selected via the trip computer stalk.
???????????????????????????????????The settings are ?????????????????????????????????comfort??????????????????????????????????????, ?????????????????????????????????normal?????????????????????????????????????? and ?????????????????????????????????sporty?????????????????????????????????????? levels of power assistance.????????????????????????????????
The XR5??????????????????????????????????????s handling has been tailored to reward the enthusiast driver, but at the same time allow for refined driving. Focus XR5 Turbo front springs have been stiffened by 30 per cent over the standard Focus and the dampers recalibrated.
Rear springs have also have been stiffened by 30 per cent and the anti-roll bar increased by 5 per cent.
"The direct benefit of this is that Focus XR5 Turbo delivers impressive grip and extraordinary road holding. Overall, the lowering of the chassis adds to the great driving experience," Wijgaerts said.
The final specifications for tyres and wheel rims were also the result of intensive testing.
The team quickly discovered that 225/40 R18 tyres were their first choice, providing plenty of space for a braking system that does justice to the power of the Focus XR5 Turbo.
High quality 320 millimetre, ventilated brake discs at the front, and 280 millimetre solid rear discs provide excellent stopping power.
"Focus XR5 Turbo provides extremely short braking distances when used precisely. This is active safety par excellence as there are performance reserves here that would only ever be called upon when driving on a race track," Wijgaerts said.
Coupled with Ford??????????????????????????????????????s ABS system, it provides the optimum braking distances even in critical situations, while EBA (Electronic Brake Assist) adds extra pressure to the system when emergency braking is needed.
Active safety was at the forefront of the engineers' minds, resulting in Focus XR5 Turbo being fitted with the latest version of Dynamic Stability Control (DSC) as standard.
DSC uses the four ABS sensors, a steering sensor and a centrally mounted yaw sensor, which constantly monitor the vehicle.
Should the driver experience a situation where vehicle control is threatened in a sudden manoeuvre, the DSC system intervenes by braking individual wheels as required.
"We worked closely with the dynamics engineers so any intervention happens relatively late, ensuring the driver maintains control and that the system does not interfere with spirited driving on open roads," Wijgaerts said.
