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The handbrake turn (also known as a bootleg or bootlegger's turn) is a driving technique used to deliberately slide a car sideways, either for the purpose of quickly negotiating a very tight bend, or for turning around well within the vehicle's own turning diameter.
The driver starts by using steering input to transfer weight to the outside tires; the handbrake is then used to lock the rear wheels, thus upsetting the adhesion between the tires and the road surface. With practice, the car can be placed accurately by releasing the handbrake and accelerating the vehicle. [1] The technique is used in some forms of motorsport, for example rallying, autotesting, drifting and motorkhana.
Many sports cars, especially UK makes such as MG and Triumph, as late as the early 1970s were offered with a fly-off handbrake option for competition purposes—the button on the end of the lever has to be pressed before the brake will lock on, which is the reverse of the normal arrangement—allowing for faster and more controlled application in a handbrake turn, and less liable to be accidentally locked on while doing such a maneuver.
In a rear-wheel drive manual transmission vehicle, it is also necessary to operate the clutch to prevent the handbrake from stalling the engine.
In a normal turn, rear wheels follow the front ones because resistance to motion in the forward direction (in which the wheels turn) is significantly less than in the sideways direction. The latter provides the centripetal force that makes the rear end of the car follow the turn. When the driver locks the rear wheels with the handbrake, both directions offer the same resistance, so the rear end tends to keep moving in the existing direction (due to inertia) and thus slides out.
Handbrake turns are primarily a technique used to negotiate tight turns in motorsport [2] but can also be used in certain other applications such as stunt or pursuit driving.
For stunt purposes, parallel parking can be completed in a single motion using the handbrake. This technique is often demonstrated at car shows, demonstrating the vehicle's agility and the driver's control. [2]
In pursuit driving, the technique can be used for turning the car around in the width of two lanes without using a three-point maneuver (see bootleg turn), for example, to bewilder a pursuer. It can also be used to quickly negotiate tight corners.
The handbrake turn has colloquially been called the bootlegger's turn in the US as it was reported to be used by bootleggers transporting illegally manufactured alcoholic drinks while escaping from the IRS. [3] It has been reportedly used by boy racers on public roads as a manoeuvre to show off to their friends. [4]
Whereas pulling the handbrake is the easiest way to start a drift, it is rarely used in circuit racing because it causes a significant loss of speed at the exit of the corner. Racers use handbrake turning only to negotiate tight 180-degree bends that would otherwise require a three-point turn.
Handbrake turns are commonly used in rallying to negotiate tight, low-speed corners, and also as a means of performing manoeuvres and stunts. [5]
The handbrake turn is not recommended for novice racing drivers, as pulling the brake with too little or too much force will not lock the wheels correctly to allow the vehicle to negotiate the corner correctly. [2]
Like other methods of inducing a drift, the handbrake turn does pose a serious risk of the vehicle flipping over, and caution must be taken when performing the maneuver with a vehicle with a high center of gravity (such as an SUV). The basic danger lies in bad judgment of surroundings, resulting in the sliding vehicle hitting an obstacle (another vehicle, a guardrail or a tree), or bad judgment of speed, resulting in the vehicle driving off the road rather than sliding, or releasing the handbrake when the vehicle is moving sideways so that all tire forces are sideways.
Left-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. It contrasts with the practice of using the left foot to operate the clutch pedal, leaving the right foot to share the duties of controlling both brake and gas pedals.
Opposite lock, also commonly known as countersteer, 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 travels around a bend with a large drift angle. The terms "opposite lock" and "counter-steering" refer to the position of the steering wheel during the maneuver, which is turned in the opposite direction to that of the bend.
A traction control system (TCS), also known as ASR, is typically a secondary function of the electronic stability control (ESC) on production motor vehicles, designed to prevent loss of traction of the driven road wheels. TCS is activated when throttle input and engine power and torque transfer are mismatched to the road surface conditions.
Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of a vehicle to steering. Oversteer is what occurs when a car turns (steers) by more than the amount commanded by the driver. Conversely, understeer is what occurs when a car steers less than the amount commanded by the driver.
Automobile handling and vehicle handling are descriptions of the way a wheeled vehicle responds and reacts to the inputs of a driver, as well as how it moves along a track or road. It is commonly judged by how a vehicle performs particularly during cornering, acceleration, and braking as well as on the vehicle's directional stability when moving in steady state condition.
A locking differential is a mechanical component, commonly used in vehicles, designed to overcome the chief limitation of a standard open differential by essentially "locking" both wheels on an axle together as if on a common shaft. This forces both wheels to turn in unison, regardless of the traction available to either wheel individually.
A Honda Accord Tafheet Drfit
Drifting is a driving technique where the driver intentionally oversteers, with loss of traction, while maintaining control and driving the car through the entirety of a corner. The technique causes the rear slip angle to exceed the front slip angle to such an extent that often the front wheels are pointing in the opposite direction to the turn. Drifting is traditionally done by clutch kicking, then intentionally oversteering and countersteering. This sense of drift is not to be confused with the four wheel drift, a classic cornering technique established in Grand Prix and sports car racing.
A bootleg turn is a driving maneuver intended to reverse the direction of travel of a forward-moving automobile by 180 degrees in a minimum amount of time while staying within the width of a two-lane road. This maneuver is also known as a smuggler's turn, powerslide, or simply bootlegger.
Trail braking is a driving and motorcycle riding technique where the brakes are used beyond the entrance to a turn (turn-in), and then gradually released. Depending on a number of factors, the driver fully releases brake pressure at any point between turn-in and the apex of the turn.
Fishtailing is a vehicle handling problem which occurs when the rear wheels lose traction, resulting in oversteer. This can be caused by low-friction surfaces. Rear-drive vehicles with sufficient power can induce this loss of traction on any surface, which is called power-oversteer.
In road vehicles, the parking brake, also known as a handbrake or emergency brake (e-brake), is a mechanism used to keep the vehicle securely motionless when parked. Parking brakes often consist of a pulling mechanism attached to a cable which is connected to two wheel brakes. In most vehicles, the parking brake operates only on the rear wheels, which have reduced traction while braking. The mechanism may be a hand-operated lever, a straight pull handle located near the steering column, or a foot-operated pedal located with the other pedals.
Lift-off oversteer is a form of sudden oversteer. While cornering, a driver who closes the throttle, usually at a high speed, can cause such sudden deceleration that the vertical load on the tires shifts from rear to front, in a process called load transfer. This decrease in vertical load on the rear tires in turn decreases their traction by lowering their lateral force, making the vehicle steer more tightly into the turn. In other words, easing off the accelerator in a fast turn can cause a car's rear tires to loosen their grip so much that the driver loses control and drifts outwards, even leaving the road tailfirst.
A J-turn is a driving maneuver in which a reversing vehicle is spun 180 degrees and continues, facing forward, without changing direction of travel. The J-turn is also called a "moonshiner's turn", a "reverse 180", a reverse flick, a "Rockford Turn", a "Rockford Spin", or simply a "Rockford" popularized by the 1970s TV show The Rockford Files. A J-turn differs from a bootleg turn in that the vehicle begins in reverse gear. It is often performed by stunt drivers in film and television shows. It can be performed both on dry and snowy surfaces; the latter is preferable while learning the skill.
The Scandinavian flick, Finnish flick, pendulum turn, or Scandi flick is a technique used predominantly in ice racing and rallying. The technique induces oversteer using weight transfer to carry a vehicle through a turn while simultaneously reducing speed.
A wheelspin occurs when the force delivered to the tire tread exceeds that of available tread-to-surface friction and one or more tires lose traction. This leads the wheels to "spin" and causes the driver to lose control over the tires that no longer have grip on the road surface. Wheelspin can also be done intentionally such as in drifting or doing a burnout.
All Wheel Control (AWC) is the brand name of a four-wheel drive (4WD) system developed by Mitsubishi Motors. The system was first incorporated in the 2001 Lancer Evolution VII. Subsequent developments have led to S-AWC (Super All Wheel Control), developed specifically for the new 2007 Lancer Evolution. The system is referred by the company as its unique 4-wheel drive technology umbrella, cultivated through its motor sports activities and long history in rally racing spanning almost half a century.
American autocross is a form of autocross, an individual motorsport in which drivers compete to set the fastest time on a temporary course. Events are usually held on large paved areas, such as parking lots or airfields. Courses consist of turns, offsets, and slaloms marked by traffic cones; new courses are typically created for each event.
An automobile skid is an automobile handling condition where one or more tires are slipping relative to the road, and the overall handling of the vehicle has been affected.
The brake balance or brake bias of a vehicle is the distribution of brake force at the front and rear tires, and may be given as the percentage distributed to the front brakes or as the ratio of front and rear percentages. The braking balance affects the driving characteristics in terms of how fast the vehicle can brake, how the vehicle can take corners, and tire wear. The optimal brake balance can vary between circuits, weather conditions and driving styles. On race cars, the brake balance is often part of the racing setup, and in formula car racing it is regularly adjusted during the course of an entire lap. In some cases, the brake balance may be adjusted to match the traction (grip) of the vehicle during braking, which usually means distributing a greater braking force to the front. In other cases, it may be desirable for the brake balance to be the more similar at the front and rear for the tires to last longer, which may be beneficial in endurance racing. Adjustment of the brake balance is often done by adjusting a proportioning valve which determines the distribution of the brake force between the front and rear brakes. The adjustment can be made via mechanical couplings or with the help of a small electric motor.