If you haven't seen a rally car at full chat, you should - especially at night

Rallying is a little different. As a spectator, standing in the quiet night woods, the first thing you're aware of is the noise. While accelerating, the rally car is very like any other racecar - loud, well-tuned, aggressive. But the first time you hear it decelerate there's a whistling followed by explosive popping - then a huge bang and a flash of flame in the woods that looks and sounds like fireworks going off.


When the car actually comes into view, you're blinded by the lights and then the fury and noise are on top of you. The lights swing away from the apex and then over it, the car slides at a crazy angle to the corner and the inside front wheel hangs over the ditch that is the apex of the turn. Brake discs glow orange through the wheels as the driver simultaneously uses the throttle and brakes to balance the car on its knife-edged slide.  The four rooster tails of gravel and dirt spray the trees on the outside of the corner, causing any fans foolish enough to stand there to turn and cover their faces for protection.


If you're a performance rally fan, you may be smiling and nodding your head at this admittedly editorial description. If you're not a fan yet, you may be shaking it wondering, “How does this work?” As a competitor, I want to tell you a few things about the technology and techniques of rally.


The technology is remarkable: the fastest cars are all-wheel-drive, two-liter four-cylinder turbos with about 330 horsepower and - more importantly - about 320 ft-lbs. of torque low in the rev range. The AWD and torque allow the car to claw at the gravel - or snow, or ice, or sometimes tarmac - under dynamic (sliding) friction rather than the static (rolling) friction that is typical of most on-track racing.


Under dynamic friction, the optimum technique is to slide the car on an angle that keeps the front wheels pointing almost straight ahead and digging in the direction of the apex. With the power full-on, the car makes an arc around the apex of the corner, even while sliding on a 30- to 45-degree angle. For a very tight corner, it may be necessary to "pendulum" the car into it by sliding the opposite direction before the corner and then flicking the car around into the correct line.


Need to slow down? On loose surfaces, sliding sideways is more effective in scrubbing off speed than straight-line braking, so rather than choosing your braking point, you typically choose where to begin your slide. When the brakes are used, it's often by the left foot, and the driver plays the two pedals like the rudder of an aircraft. Pressing on the brake a little to transfer weight to the front of the car will increase the slide angle (and tighten the arc of the corner), and pressing on the throttle to transfer the weight to the rear will straighten the car out to open up the line. "Trail braking" makes no sense in a rally context; the way to initiate the slide into the corner is actually to turn the steering wheel and then stab the brake for a quick transfer of the weight to the front to dig it in and destabilize the tail. After that, you're feathering the brakes all the time for balance.


In order to be able to do the weight-transfer dance, it is necessary to have instant power on tap even at low revs - not a typical strength of a turbocharged engine. To cure this, all the leading cars have a turbo anti-lag system incorporated in the engine management computer that hugely retards the timing when the driver lifts the throttle. The exhaust valve is already open when the spark plug fires so the explosion doesn't push the piston down in the cylinder. Rather, it fires out the manifold and keeps the turbo spinning - this is the explosion and flame out of the tailpipe.


The racing line is a bit different too - if early-apexing is bad on the track, it's deadly in rallying. Typically we have little or no idea what's around the bend, and so a late apex is generally the rule. Combine this with the "sliding-to-brake" and the "turn-first-then-brake" techniques described above, and you can see why it takes a certain about of courage (or stupidity) to do it right. You have to trust that the car is going to claw through its late-apex slide and not fly off the outside.


Jumps have their own special challenges – chicken out and lift the throttle on the launch and you’ll soon have a shorter front bumper. You have to brake a little just before launch then accelerate off the crest. And try to land one wheel at a time (ever seen a cat land?) so the rebound isn’t synchronized, or you’ll get a bonus jump after landing. Oh, and be sliding a little sideways over the crest – you never know which way the road is going to go on the other side.


Last but certainly not least, there is the strategy : for 300km you have to stay on the road, make the car last, know where to capitalize on your competitors, and pace your and your co-driver’s emotions to be on the razor's edge only when it's most important. Of course, you still have to go obscenely fast. You just have to go fast, smart.


Got that? Good. Now you’re flirting with the laws of physics. See you in the woods in 2003.