The Essence of Car control

A number of members started a thread in the Mailing List regarding the Scorpios handling and the effects of rear wheel drive.

One of the more knowledgeable members offers the following :-

"The police driver training emphasises smoothness at all times. Gentle movements on the accelerator and the steering wheel, and even the brake pedal, which should be smoothly applied and then force applied as necessary, easing up and feathering to a stop. The instructor wants to hold a cup of tea in his hand without having it slop into his lap, and the only way he should know that you have changed gear is by the change in the engine revs.

Before even reaching a skid pan he sticks a plate and a loose golf ball on the bonnet while you drive round a car park. If the golf ball rolls off you're not ready for the skidpan yet. You are required to provide a running commentary which must include everything that might influence braking, acceleration and steering. Road signs, bus stops, condition and type of road surface, road markings, pedestrians, trees (for leaves on the road) junctions, empty or with traffic, cars coming towards, cars behind, speed limits, road lighting, bends, humps and switchbacks, high hedges. Every road sign must be announced with its correct meaning and the hazard it warned of must be mentioned when it appears. This is when you could be driving at 100mph - a speed which it is your responsibility to decide is safe at that moment.

After 45 minutes of that you feel like you've been through a wringer. Oh, and any speed limit (not the National one) which is exceeded costs you a round of milky coffees. The idea is perfect control of the vehicle - points are even deducted for driving over too many cats eyes when changing lanes - so that every single hazard is considered and prepared for, and nothing takes you by surprise.

Braking is ONLY WHEN IN A STRAIGHT LINE because touching the brakes while on a bend or corner can cause a skid. The essence of car control is that all excess speed is scrubbed off by the brakes (NOT the gears) and then the correct gear is engaged (double de-clutching for the smoothness, then the maneouvre, followed by rapid acceleration through the gears, hardest when back in a straight line. If done correctly the golf ball stays in the dish because the G force in any direction never exceeds the gravity of the golf ball in the cupped surface.

Taking any bend in the wrong gear or speed will cause the car to lean over - this is called 'doorhandling'. Severe cases will cause the instructor to lick his finger and stick it in your ear. With a cold and wet ear you try better next time. On the skid pan, you are taken round a few times and you can actually drive round it without skidding at all if you are very smooth.

Then you are taught to start the tail ender by pressing on the accelerator and twitching the steering wheel to the right. The back end slips out to the nearside and you keep it there with left movements of the steering wheel and raising and lowering the power to the rear wheels. Although you are applying left/centre steering, your are traversing a right hand circle and you can 'float' the car round and round in circles with the back end out and the tyres spinning. Its great fun, but the moment you lose control - you can feel that moment through the seat of your pants, as WW1 pilots used to say - then the rear overtakes you on your left shoulder and you do a complete 180.

The better you can anticipate that moment, the faster and harder you can 'float' the car round the circle without losing it, and once you have the knack you can float the car at amazing speeds round the cone with the steering wheel almost stationary and controlling the float just with the accelerator. Don't try it at home, though folks. The triumph is when you want to leave the circle. You approach the exit road and at the right moment brake/accelerate and twitch the steering wheel the other way, so that the nose of the car is facing a cone and remains stationary, while the rear of the car floats round behind you to the offside. You then check this skid with steering moment to the right and then centre the steering as the cone floats away to your left, and the car drives straight into the exit road.

When you get it right the effect is magical, and you want to do it again and again. Out in the wilds of Norfolk I used to practice this using some traffic cones and a farmers hardstanding when it was covered with ice. I would approach a traffic cone in the centre, start the skid and float the car 360 degrees round the cone with the front of the car facing the cone, then check and cancel the skid and continue the original direction. The skid training was only it you make a mistake.

In the police system you should never skid, because the car is always balanced for bends and roundabouts. The best way to get out of a skid is never to get into one. If you feel the rear of the car slipping to your left, lift the foot off slightly to reduce the power to the wheels and steer into the left. The front will now meet the movement of the rear and the car will be in line again, while the wheels have regained traction because you lifted off. You will feel it re-align, and this is called the check. Now apply slightly more gas and steer the car with very gentle movements around the remainder of the hazard.

The best thing to do is to find a deserted car park in winter and practise. You will find its easy to start the skid, and as long as you lift off and steer towards the direction your rear wheels are going you will also find it's very easy to correct it, providing you have the room. It's a skill which you will do instinctively once you've learned it, and it's great for frightening a mother-in-law - provided you don't over do it. Most inexperienced drivers are taken by surprise by a skid and do one of two things - both of which make things much worse. They stamp on the brakes - which simply starts a crabwise slide into something nasty and painful, or they steer the wrong way, which increases the angle of the skid, or they do both, which is disaster. It is not instinctive to steer towards the hedge looming towards you on the nearside, which is why many people can't get out of them. The movement is only momentary, and SMOOTH movements of the steering and gas regains control.

After a long dry spell, (any weather without rain for 10 days is called a drought) the roads are covered with brake dust, specs of rust, drops of trans and engine oil, grease from tree sap, leaves and bits of mud from farm vehicles. There may also be spills of diesel which sinks below the level of the stones in the road surface. But a light gentle drizzle then turns all these substances into a shiny grease which you can see on the road, and the traction available to the tyres may be a tenth of what you're used to. This catches out many drivers who drive exactly as they have always done, and apply too much power while the steering is off-centre, such as a roundabout. The spinning rear wheels then shift the car away from wherever the steering wheels are pointing - and a skid is born. I thoroughly recommend a turn on a skid pan, or by one of those hydraulic dollies that lift the road wheels up. It's great fun, but once you have done it you will better understand both how to get out of a skid, and more important, how never to get into one."