Extreme and defensive driving. Dmitry Aleksandrovich LiskinЧитать онлайн книгу.

      The figure shows the total equivalent forces, when a high-friction differential is installed on the machine. A high-friction differential transfers more than half of engine’s torque to rear loaded wheel. The increased traction on rear loaded wheel pushes the car even deeper in the direction of drift (to the left in the figure plane). An addition increase of the torque on rear loaded wheel leads to an increase of engine power transmitted to this wheel.

      Thus, the same time pressing the throttle and brake pedals on a rear-drive car creates understeer and allows you to get out of drift. In the future this method of fighting with drift on a rear-wheel-drive car will be called a defensive “throttle+brake” technique. As a rule, at drift angle of approximately 45 degrees (the angle must be checked for each car) and more “throttle+brake” technique does not work, since traction on rear loaded wheel causes car to turn around.

      It is important to understand, that “throttle+brake” technique forced a car to move straight. When performing the technique drifting stops, the machine continues to move in a straight line in the same direction, in which it was moving before performance the technique. Therefore it is necessary to calculate trajectory and duration of “throttle+brake” pulse. If a driver has reacted to drift in time, a short impact on the brake pedal and steering correction may be enough. Note, that “throttle+brake” technique allows you to get out of drift, without turning the front wheels.

      Since the front wheels are locked, it does not matter, which way they are turned. But to successfully take control at the end of the technique, when the front wheels are in locked condition, you should put the steering wheel straight. There are two reasons for this:

      • the suspension geometry is such, that when the front wheels are turned by the steering wheel, the front of car come down; the straighten wheels will lift the front of car back; the greater front clearance – the lower steerability;

      • if the front wheels are set in the straight position, car will remain neutral behavior after releasing the throttle and brake pedals (the car’s behavior will not change).

      At the end of “throttle+brake” technique it is enough to align trajectory with a corrective steering. If it is necessary to avoid an obstacle or bend trajectory because of other reasons, you should turn the front wheels previously, during perform the technique, when the front wheels are locked.

      The torque transmitted to rear loaded wheel depends on engine torque. If engine torque is high enough, efficiency of “throttle+brake” technique may fall: when together pressed the throttle and brake pedals the rear wheels start to skid. In this case to exclude skidding of rear loaded wheel, you should limit effort on the throttle pedal during performance the technique.

      For “throttle+brake” technique to work on a rear-wheel drive car, the brake system must be properly configured. It is necessary, that both front wheels are locked when the brake pedal is fully pressed both when moving forward in a straight line, and when passing corners to the left and right or when the car is in a drift. In addition, the braking effort on the rear wheels should not be too high, and engine torque should not be too low. If the rear wheels will be locked, the engine will stall.

      Requirements for successful exit from a drift on a rear-wheel-drive car with help of “throttle+brake” technique

      • both front wheels must lock when the car is in a drift;

      • the rear wheels must not be locked;

      • skid of rear loaded wheel should not occur;

      • differential friction should not be too high;

      • drift angle should not be greater, than about 45 degrees.

      The last two requirements are very conditional. Performing of the technique may differ on different machines, so you need to perform concrete tests. It is not difficult to test “throttle+brake” technique: you just need to provoke a drift and press the throttle and brake pedals.

      It was not said, but was obvious, that to perform the above-listed techniques an anti-lock system should not be installed on car, which prevents the wheels from locking by the brake system. In the presence of an anti-lock system it is impossible to perform defensive “throttle+brake” technique on a rear-wheel-drive car.

      Recommendations for driving a car in a drift

      • while driving car in a drift, your hands should be relaxed, you do not need to hold the steering wheel with a death grip;

      • while drift turn your head and direct your gaze along the direction of movement of car, keep the hood in the background, so you will definitely feel angle of drift;

      • when fighting with a deep drift direct your gaze forward, through the windshield – this will help you maintain your orientation in space.

      Notes on performing of “throttle+brake” defensive technique on a rear-wheel-drive car

      • during perform the technique you should to straighten the front wheels or turn them by the steering wheel in the direction, in which you want to continue move at the end of the technique;

      • if the engine torque is quite high and the rear wheels start to skid when performing the technique, you need to limit effort on the throttle pedal: the traction on the rear axle is only needed to unload the front;

      • the duration of the technique is controlled according to trajectory of movement.