Safe passage for Bentley owners as the UK struggles to cope with heavy snow
As heavy snows affect most of the UK causing treacherous motoring conditions for most sports car owners, the Bentley Continental Series permanent four-wheel-drive and advanced traction control systems come into their own providing far safer levels of control & always in exquisite luxury.
Why?
Bentley’s All-wheel drive system
Pointing the power in four directions was part of the original strategy for ensuring the current Bentley range would remain, safe, usable and enjoyable in all weather conditions routinely found around the world.
The system used employs a central Torsen (TORque SENsing) differential and a free differential on each of the front and rear axles. Both the front and centre differentials have individual cooling radiators.
After exhaustive investigation and a substantial test programme of available alternatives, Bentley's engineers decided to divide the drive equally between the front and rear axles, giving a conventional 50:50 torque split. This is the combination that was found to be best at providing not simply the safety demanded of a car with this performance potential, but also the most favourable handling response.
Naturally this front to rear ratio is infinitely variable according to available grip and the Torsen differential together with the 4 wheel ASR can sense slip of less than one per cent and act accordingly, apportioning the engine's torque to either the front or rear axle. It would, in reality, take exceptional conditions for this to happen such as both wheels of one axle being on black ice but in more conventional circumstances the Torsen differential will always be able to optimise the torque loadings between the axles.
Thanks to Bentley’s advanced electronic stability programme, the need to equip each axle with a limited slip differential is obviated. When slip is detected at one wheel, the ESP system can apply the brake individually to that wheel and allow the torque to be transferred across the axle to the tyre with the most grip. In normal use this system acts entirely unobtrusively but it does, in fact, possess the ability to keep the car moving forward when traction is available to just one of its four wheels. It is true that luxury coupés rarely find themselves in these conditions but it is also true that this is because their hitherto practical limitations have tended to keep them from places where such circumstances are more likely to occur. But with all-wheel drive, advanced traction and stability systems (not to mention its spacious interior, large boot and ski-friendly through-loading facility), the Continental GT will easily take its occupants to remote mountain resorts where no other luxury coupé would dare to follow.
Electronic Safety Systems
Bentley takes the responsibility of putting a 200mph car on sale to the general public extremely seriously and, in addition to the clear traction advantage afforded by its all-wheel drive hardwear, Bentley's engineers have been working just as hard to make sure the software is there to back it up too.
ABS anti-lock brakes, HBA (Hydraulic Brake Assist) and EBD (Electronic Brakeforce Distribution) in conjunction with the varied array of other defences designed to keep the car under control.
These include ASR traction control that employs the ABS sensors to detect when traction is lost at either end due to a combination of a low grip surface and an excessive application of power. Under these circumstances, the ASR will instantaneously cut the power until traction is restored.
As mentioned earlier, Bentley also feature the latest Electronic Stability Programme. This ESP system, which necessitates the use of a fly-by-wire throttle, operates by a system of sensors analysing a number of different parameters such as speed, throttle opening, steering angle and the car's yaw and pitch. When one of these parameters is breached, indicating a possible or impending loss of control, the ECU is informed and appropriate action is taken. Depending on the nature and severity of the situation this might amount to little more than throttle modulation or it could involve the targeted application and release of individual brake callipers until full control is restored.
The final weapon in this armoury is MSR drag torque control. This is an intermediate, electronic control system, designed to intervene before a potential loss of control is address by ESP or ABS. During deceleration it modulates engine braking to ensure deceleration is consistent, swift and helps remove the possibility of a wheel locking when the transmission changes down on a reduced grip surface.
Did you know……. ?
Bentley holds the world ice speed record
March 2007 Oulu, Finland - A Bentley Continental GT, driven by four-times World Rally Champion Juha Kankkunen, smashed the world ice speed record, reaching an average speed of 199.86mph (321.65km/h) on frozen sea off the coast of Finland.
The near standard four-wheel-drive Continental GT - which is privately owned by the world rally star - eclipsed the previous ice speed record of 184.14mph (296.34km/h), set by a Bugatti EB110 Supersport at the same location.
Kankkunen's team endured temperatures of minus 30 degrees Celsius on a 10km section of frozen sea, 50km north of Oulu in western Finland. Accelerating hard over 70cm-thick ice, Juha took around 5km to hit his optimum speed before reaching the start of the marked kilometre over which his speed was measured. In spite of the Continental GT’s exceptional grip and traction he experienced wheel-spin even above 120 mph.
After a brief check-over, Juha turned the Continental GT around and drove the measured kilometre a second time to fulfill the judge's requirements, peaking at an incredible 205mph (330km/h).
Yesterday, a further attempt to better this speed resulted in an even higher peak velocity of 206mph (331km/h), but bettering the average figure set a few days before proved impossible due to an increasingly rough and snow covered track.
'The Bentley performed impeccably,' said Kankkunen. 'I was amazed how stable and secure it felt at these high speeds, despite the track's rough and icy surface being scattered with powdery snow. I even managed to stop the car from its top speed within 600 metres.'
Modifications to Juha's Continental GT were kept to a minimum. For safety reasons, a rollcage was fitted, along with Nokian snow tyres. Various aerodynamic tweaks were also made, but the powertrain was essentially untouched, although the car ran non-standard fuel with matching calibration to cope with the extreme temperatures.
'Juha's record-breaking achievement is just what we've come to expect from some of our more adventurous owners,' said Dr. Ulrich Eichhorn, Member of the Board, Engineering. 'It shows that the spirit of the famous Bentley Boys lives on and is still harnessed by drivers with sufficient skill and courage to extract the full potential of our motor cars in extreme conditions - though, naturally, we would not recommend our other owners try to attempt such high speeds on sheet ice!'
This most recent world record set in a Bentley continues a long tradition started in the 1920s when some of W.O's Bentley Boys set the pace at European circuits. In 1922, John Duff drove his Bentley 3 Litre single handed for 24 hours, at an average speed of almost 87mph at Brooklands to secure a Class record. And in 1928, another 3 Litre driven by Dudley Froy became the first car to achieve more than 115mph over a distance of 100 miles at the same venue.
