Scandinavian flick
Encyclopedia
Rallying
Rallying, also known as rally racing, is a form of auto racing that takes place on public or private roads with modified production or specially built road-legal cars...
. While approaching the turn the driver applies a slight steering input to the opposite direction of the turn, then steering into the turn, while sharply lifting off the throttle and (in some cases, depending on speed and type of layout) lightly applying the brakes. This will cause the car to slide sideways facing slightly away from the turn. Then steering input is applied towards the turn and as the driver releases the brake pedal while still holding down the throttle the car will slingshot itself around the corner to the desired direction. Of course, countersteering will again be required to control the induced oversteer. A recent research paper initiates a mathematical analysis of this technique.
This technique is used to help the driver get around corners that have an increasing radius, but it is also used as a show off as the result of the flick involves the car oversteering heavily.
Origin of the name
Though it's not clear who was the first one to invent it, the technique is named after the Scandinavian rally drivers of the '60s who widely used it. The front wheel driven cars of 60's, like the Mini, were easier to turn in if brake pedal was stabbed to induce weight transfer from rear to front and rear grip reduced until it started to slide. The "flick" part comes from the technique of "flicking" the wheel in a direction opposite of the turn to build up angular momentumAngular momentum
In physics, angular momentum, moment of momentum, or rotational momentum is a conserved vector quantity that can be used to describe the overall state of a physical system...
.
The Scandinavian rally drivers were, and still are, predominantly the best drivers in Europe for driving in ice and snow conditions, due to their inclement weather in winter months. Because they drive on ice and snow regularly, they were the first drivers to develop techniques to drive at speed in these slippery conditions. The Scandinavian flick was first used by drivers such as Ari Vatanen in WRC events on non-cold weather surfaces, and as such, the name has stuck.
Since the concept was understood and developed, it has also found its way into drifting and tarmac driving event, even as far as Australia where it has been seen used to induce oversteer in V8 Supercars.
Physics involved
Every time you turn, your vehicle resists the change of direction due to inertiaInertia
Inertia is the resistance of any physical object to a change in its state of motion or rest, or the tendency of an object to resist any change in its motion. It is proportional to an object's mass. The principle of inertia is one of the fundamental principles of classical physics which are used to...
. This resistance results in a phenomena known as understeer, which seems to push the vehicle outward during the turn, this is due to the loss of traction between the front (steering) wheels and the road surface. This is particularly noticeable in Front Wheel Drive vehicle, as the drive to the wheels for a given throttle input overcomes the traction of the tire to the road surface (more power to the driven wheels creates more loss of traction, hence powerful Front Wheel Drive vehicles suffer with understeer). This is partially neutralized by the friction between the tires and the road, so the vehicle rather tilts than slides, but ultimately the front wheels will break traction in a corner. In some rear wheel driven vehicles, the suspension geometry is set up to create "push on" understeer, as this is easier to deal with for the driver than un-predictable and harder to address oversteer). As you abruptly flick the steering wheel in the opposite direction, the inertia of the vehicle that has been trying to slide in the opposite way is added to the force applied by the engine and the friction of the front wheels, thus exceeding the force necessary to break traction between the tires and the tarmac. Since most cars have their engines in the front
Automobile layout
In automotive design, the automobile layout describes where on the vehicle the engine and drive wheels are found. Many different combinations of engine location and driven wheels are found in practice, and the location of each is dependent on the application the vehicle will be used for...
, the load on the rear tires is less, so they break traction first, effectively causing the rear to slide out. Suddenly lifting the throttle causes additional weight transfer to the front, making the load on the rear wheels even less.
Real life usage
Most cars today are FWD and prone to understeerUndersteer
Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of a vehicle to steering. Simply put, oversteer is what occurs when a car turns by more than the amount commanded by the driver...
. This makes a vehicle stable at high speed but requires larger steer inputs near the limits of adhesion. Skilled drivers are able to allow for understeer by using a maneuver similar to the Scandinavian flick, though with less steering input and control the possible slide by using an opposite lock. In the best of cases, the driver would use the inertia of the feint to make the car enter the bend without initiating a slide. This requires excellent knowledge of the specific car. However, less skilled drivers must not attempt to use this technique, as it can prove very dangerous.
The ability of a vehicle to handle sudden changes in direction at high speeds without sliding or rolling over is assessed through the so-called Moose test
Moose test
A moose test or elk test is a test to determine how a certain vehicle acts when the driver evades a suddenly appearing obstacle...
. This scenario occurs when the driver is trying to avoid an obstacle (allegedly a moose
Moose
The moose or Eurasian elk is the largest extant species in the deer family. Moose are distinguished by the palmate antlers of the males; other members of the family have antlers with a dendritic configuration...
, or any other large animal that may appear on the road) in his or her lane and then returning to the lane to avoid oncoming traffic. The succession of sharp turns in opposite directions combined with lifting off the throttle is exactly how the Scandinavian flick is performed. Since the technique is used at race speeds, it's not normal for a vehicle to start a slide while driving at cruise speeds.
It is possible to induce oversteer at 30 mph (45 km/h), which is well in the cruise speed range. However, it is not likely that in real life the driver would change the steering input from hard left to hard right within 2 seconds.
Of course, when driving in winter in Nordic countries, one can utilize flick even at low speeds. This technique is trained by some countries in the Scandinavian/Noric regions during basic driver training. It may also be trained in the UK for professional drivers (Police, Emergency Medical Response, Military) who may be required to drive on snow tires
Snow tires
Snow tires are tires designed for use in winter conditions, such as snow and ice. They are an alternative to the use of snow chains.Snow tires are usually tires with a different rubber composition from all-weather tires...
in ice/snow conditions, as a vehicle can behave differently and require different driver skills in winter conditions.
It is frequently used by former racing driver Tiff Needell
Tiff Needell
Timothy "Tiff" Needell isa British racing driver and television presenter. He is best known as a former co-presenter of Top Gear and current co-presenter of Fifth Gear.-Biography:...
on the motoring programme Fifth Gear
Fifth Gear
Fifth Gear is a motoring television magazine show from the United Kingdom. Originally shown on Channel 5, the show is currently presented by Tiff Needell, Vicki Butler-Henderson, Jason Plato, Jonny Smith and Ben Collins...
and previously during his time as a presenter on Top Gear.
It was also used in the BBC television series Top Gear, in which Richard Hammond
Richard Hammond
Richard Mark Hammond is an English broadcaster, writer, and journalist most noted for co-hosting car programme Top Gear with Jeremy Clarkson and James May, as well as presenting Brainiac: Science Abuse on Sky 1.-Early life:...
tries to achieve the Scandinavian flick whilst cornering in his "lightweight, mid-engined" Suzuki Super Carry
Suzuki Carry
The Suzuki Carry is a kei truck produced by the Japanese automaker Suzuki. The microvan version was originally called the Carry van until 1982 when the van was renamed as the '...
. The result was a less than spectacular roll-over to its side.
Usage in drifting
In terms of drifting, the Scandinavian flick is classified as a weight transfer drift. It is also known as a Feint drift or Inertial drift. It's widely used in rallyingRallying
Rallying, also known as rally racing, is a form of auto racing that takes place on public or private roads with modified production or specially built road-legal cars...
, because it is simple to perform and does not require engine power, nor does it cause a loss of speed at the exit of the corner. A drawback of the technique is that it requires somewhat wider tracks than the other drifting techniques.
Many drift drivers will utilise the feint or weight transfer drift on track, in order to send the rear of their car into a more accentuated drift where the track width allows them. In most situations, this is preferable to drivers of lower powered cars, who cannot induce a drift with engine power alone, but it is also useful to drivers of turbo charged cars, when they find that their car is not "on boost". Many japanese based vehicles use smaller capacity engines with larger turbos, so can "fall" off the power band created by the forced induction. The alternative methods to create power pre-corner include the feint drift incorporated with a "clutch kick", which starts the weight transfer, but allow the engine to free-rev and create boost pressure in the turbo to create more power to break the traction of the rear wheels when the clutch re-engages on the drivetrain with the car unsettled.
Dangers
There are two basic dangers when performing the Scandinavian flick- If the center of gravity is too high (as in a SUV), there's a great chance the vehicle would roll over instead of sliding.
- It takes practice to learn how to control the vehicle during the slide. A less experienced driver would be prone to overcompensating for the slide and driving off the bend.
Also, a drift is not likely to occur if the camber
Camber angle
thumb|100px|From the front of the car, a right wheel with a negative camber angleCamber angle is the angle made by the wheels of a vehicle; specifically, it is the angle between the vertical axis of the wheels used for steering and the vertical axis of the vehicle when viewed from the front or...
of the rear wheels is set too negative. On the other hand, if the camber of the front wheels is set too positive, they will break traction in the same moment the rear ones do, so the car will slide uncontrollably rather than pivoting around the front wheels.
See also
- Drifting (motorsport)Drifting (motorsport)Drifting refers to a driving technique and to a motorsport where the driver intentionally over steers, causing loss of traction in the rear wheels through turns, while maintaining vehicle control and a high exit speed...
- Left-foot brakingLeft-foot brakingLeft-foot braking is the technique of using the left foot to operate the brake pedal in an automobile, leaving the right foot dedicated to the throttle pedal...
- Moose testMoose testA moose test or elk test is a test to determine how a certain vehicle acts when the driver evades a suddenly appearing obstacle...
- Opposite lockOpposite lockOpposite lock, also commonly known as counter-steering, is a colloquial term used to mean the steering associated with the deliberate use of oversteer to turn a vehicle rapidly without losing momentum. It is typified by the classic rallying style of rear-wheel drive cars, where a car appears to...