Techspecial: Torque Vectoring AWD in the Focus RS

Posted on 08-02-2015 at 20:55 by Dizono – 40 Comments”

One of the big surprises of the new Ford RS was all wheel drive. That turns out not to be conventional system, but can the traction forces is very specific to certain wheels lead. We dive into the technique and you lay out how the Focus RS its forces to the road surface.

Ford is well known for its excellent chassis and with the new Focus RS so a name to uphold. Was the previous Focus RS is still a voorwielaandrijver, the new has drive to all four wheels. Ford assembles not just the first passive system in its ultimate hot hatch, but does the business equally thoroughly. The torque of the 2.3-liter four-cylinder ecoboostmotor, immediately after the transmission, by a power transfer unit (PTU) distributed about the front and rear axle. This is going to be dynamic, there can be up to 70 percent of the available torque to the rear axle to be led. There divided a differential, the traction forces on both rear wheels and also this is going to be dynamic.

Haldex-clutch
How Ford the traction forces are going to distribute between the front and rear wheels does the manufacturer not from the cloths. Oppositelock notes that the system is similar to the AWD system that Saab used in the 9-3. That system makes use of a Haldex-clutch. In the most simple form ensures a Haldex clutch ensures that the rear wheels only are powered when the front wheels to grip lose. This would make the car so most of the time model year. In the case of the system in the Ford (and Saab) this should be nuanced, in the press release, the car manufacturer about the preventive distribution of the traction forces on the front and rear axle. So already before the front wheels lose traction, the rear wheels powered. How determined is when there is how much power to the rear wheels, remains a mystery, but the many sensors in the car will surely have their bit to contribute.

Torque Vectoring
Thanks to Torque Vectoring the torque on the rear axle to a maximum of one hundred percent to one of the rear wheels to be led. The diff is fitted with two electronically operated and hydraulically operated plaatkoppelingen that the torque split on the rear wheels. Controlled by a control unit which is a hundred times per second with various sensors to measure the steering angle, how much throttle is given, which wheels have the most grip, and many other variables, the system determines how much torque to the front and rear wheels should be and how it should be individually distributed to the rear wheels. When you turn to the left to submit, the Torque Vectoring system, the traction forces on the rear axle for a larger portion to the right rear wheel lead. How much power to the outer rear wheel is guided, depends on your speed and the extent to which you are submitting. By the unequal distribution of the forces over the rear wheels, the car is, as it were, the curve insertion. Exactly the opposite to a normal open differential, but the inner wheel more torque gained because that wheel is less resistance problems. As we recently explained in an article on electronic differentials, is prejudicial to fast cornering because it is precisely that inner wheel is generally the least grip.

Special front suspension?
The previous Ford Focus RS knew his 305 hp (350 hp in the case of the Focus RS500) are particularly well transmitted to the front wheels to get. Normally, you would do with a model year car with such a power lot of torque steering expect. Who agree with a voorwielaandrijver full throttle through a turn is torn, which has the sturdy feel in the steering wheel. Not only is that feeling in the steering wheel is not pleasant, it can also cause your car deviates from the planned track. Ford has developed for the last RS, a special steering system, called RevoKnuckle. The name may have been sound, the system ensures that the parts of the powertrain are not directly connected with the steering system and also worked in practice extremely well.

It is not completely clear, or Ford for the new Focus RS this system applies, in the released information is only spoken of a more rigid front suspension knuckle design. Thanks to the all-wheel drive is the RevoKnuckle system is probably redundant. Send you with much gas in a turn, then have the front wheels yet, but thirty percent of the total torque to the asphalt. Ford reported that the undercarriage is still a bit harder and stiffer is adjusted than in the recently launched Focus ST. Wouter was already under the impression of the base of this swift Focus, the expectations for the RS are so sky high. All that technical talk is great and all, ultimately, only the practice.