The Tough Dog Tuff Truck Challenge

It's dark now, and there's a storm brewing up on the hill. For the past few hours, TopGear snapper Thomas and I have been watching from a safe-feeling distance as the crowd - fuelled by the on-track chaos and dripping in beer, sweat and testosterone - has swollen in both size and ferocity. It's now pulsing like a hurricane-ravaged river set to break its banks.

What began as a booming cheer every time a truck failed has morphed into a non-stop wall of sound, regardless of what's happening on track. There's something happening in the eye of this boozy storm. Something that's keeping them entertained.

Thomas and I share a look that's equal parts fear and resignation. There's nothing else for it. We're going to have to go in. We push our way into a scene previously only found in one of Tolkien's nightmares. Shirts are optional. So are trousers. Someone thrusts a shoe filled with a foul-smelling liquid into my hands - though how much of the stench is down to the shoe and how much is the liquid is unclear. Then suddenly it's not. "It's a ritual here," I'm told by a marginally less-intoxicated clansman. "You need to drink beer out of your shoe. Or someone else's."

It's day two of a three-day event. It's hot. It's muddy. And showers are virtually non-existent. And they're drinking out of each other's shoes. Someone's brought a pushbike, and he's been challenged to jump a rubbish bin. The fact that, whether he succeeds or fails, his trajectory will put him and his bike smack bang in the middle of the group of spectators appears irrelevant.

He jumps and collides with a shirtless, bald giant, knocking him down. The giant's back on his feet in a second, bellowing loudly before pouring a beer on his head. There seems to be a bit of that going around. Flares go off. People yell. It's madness. Welcome, then, to the Tough Dog Tuff Truck Challenge. Spread over three booze-and-mud-stained days, it's Australia's biggest extreme 4WD event, with 61 teams, 10,000 spectators and a total prize purse of around £20,000.

The event unfolds deep in 4WD country - a muddy, mountain-ringed outpost some three hours outside the suburban sprawl of Sydney, Australia. The distance is important. An event like this needs space. Needs camping. Needs fires and beer and bonding and insanity. And, perhaps most importantly, it needs to be far, far away from civilised society. Which is at least partly why we'd never even heard of it. It's a secret society of petrol-headed mayhem. And it's growing in Australia at an exponential rate.

The rules are fairly straightforward. There's a time limit attached to each of the 10 obstacle-strewn courses, but for insurance reasons, it can't be called a race. Instead it's a test of technical skill, with 10 points awarded at 10 different check points on each track, along with a bonus section worth another 10. Points are deducted according to a set of 39 penalties - engaging reverse, for example, might cost you five points, while clipping a bollard or the safety tape might cost you 10 points. Each team consists of a driver, a navigator and a support crew ready to fix whatever goes wrong. Lots will go wrong. The navigator travels outside the truck - everything is run at walking pace - calling out the most worrying obstacles to the drivers through a headset comms system. There's no penalty for failing. If you make it halfway through a track before your truck collapses, then you're awarded however many points you'd tallied so far, then you try to fix whatever went wrong and move on to the next one.

And everybody fails. The tracks, devised by event mastermind - and presumed Saw movie fanatic - Peter Antunac, are designed to cripple and maim as many competitors as possible. Boulders the size of hatchbacks, seven-metre-deep trenches filled with mud, telegraph poles and those huge tyres from mining trucks, impossibly vertical rock climbs, and a midnight 'mystery' run through the forest with nothing but headlights for guidance, all conspire to narrow the playing field.

The tracks are so brutal, in fact, Peter's been forced to bring in an entire fleet of sling-enabled excavators, ready to rumble in and pluck twisted, flipped or wedged 4WDs off the tracks, the crowds cheering and jeering for the stranded driver the whole time. No driver wants to hear that excavator coming.

It's the ultimate sign of failure - like being relegated to the spare car in a TopGear TV challenge. And, yet, despite the beer-stained hooliganism of it all, there's a family friendly atmosphere - albeit more Addams than Brady - to the event. There's a generous smattering of kids sitting atop dads' shoulders. No shortage of pram-pushing mums, either. Few spectators have teams to cheer for. They're just here to see some quality driving. If someone bails on an obstacle then the mob turns on them with the ferocity of a prison riot, but largely they just cheer for anyone willing to have a go. "We just come to see a good drive," says long-time fan Alex Clifton. "There's no other type of motorsport where you can get this close to the action like you can here. Sure, you've got your Toyota fans and your Nissan fans, but mostly people just want to see the drivers do well."

Fans like Alex perfectly encapsulate the spirit of an event like this. As you read this, he'll be holed up in his garage putting the finishing touches on a truck he hopes will carry him to the top step of the podium in the 2014 competition. He's never driven competitively before, but the fact he's built a car is all the qualification he requires. There are few kinds of national, respected, real cash prize-giving professional race series that still push an if-you-build-it-you-run-it ethos. "We haven't tested it yet, but we reckon it'll be pretty good," he tells us. "The thing about something like this is that every truck here can compete; it doesn't matter if it's worth $10,000 or $100,000 - everyone has a pretty good go."

That includes the crowd. Police-tape style safety markers stretched millimetres off the track are all that separates the spectators from a couple of tonnes of probably-soon-to-be-upside-down metal. The crowds are so close they can, and do, offer advice to both driver and navigator, generally ranging from the sage "A little more to the left", to the somewhat more unhelpful "Just f***ing have a go, you girl".

But they're a tough breed, the drivers, who tackle these phenomenally cruel tracks with the mild consternation of a grossly overweight man tackling a flight of stairs. And of all the pumped and primed trucks on display, car 05 stands out above all others - Team OPW's Toyota Land Cruiser FJ40 so heavily modified it's barely recognisable as one of its street-going brethren.

The custom-built truck sits on 42-inch Interco tyres with military-spec Unimog axles. The interior is stripped back to exposed metal, and the dash is covered with the kinds of switches you'd expect to find in a Virgin Galactic cockpit. They control everything from the four-wheel drive system to the rear steer, power delivery and independent front and rear braking. Laughably, the trucks still need to 'resemble' their road-going counterparts, so each is equipped with windscreen wipers, cleaning jets and indicators.

But car 05's in trouble. A top-five finisher these past three years, OPW's truck is considered to be the most heavily engineered and most talented vehicle here. More than £65,000 worth of parts has been sunk into it - a massive number when you consider the bulk of its competitors are running cars they've built in their garages using little more than beer and hope. But, as sometimes happens with a heavily tipped favourite, things aren't going well.

On day one, a freak accident - the lateral travel in car 05's wheels is so extreme that one bent inward and collided with the alternator, requiring a trip to town to try to find another one - followed by a comms fault that meant the driver and navigator couldn't talk to each other, has seen the team fluff the first four races. The scoring at the Tuff Truck Challenge is blind, but the drivers know when things aren't going well. And things aren't going well. "We've had a tough start," the car's pilot Tazz tells us when we catch him at the start line of the next track. "That alternator thing was unbelievable, and then the intercom thing meant we were basically driving blind. We've got a lot of catching up to do."

As night falls on day two, though, the team's mood has improved slightly. The team has aced the day's final stages: a performance they hope is enough to propel them within touching distance of the competition leaders. But to mount a serious challenge, they'll have to tackle the mud.

During the day, the crowd is spread out over the event's 10 tracks but, as night descends, their collective attention focuses solely on a track called Mudrat's Revenge. Considered the event's only high-speed run, the Mudrat consists of four mud-filled trenches deep enough to swallow a car whole, and lined with hidden truck-crippling obstacles like boulders, telegraph poles and giant tyres. It's brutal. Of the first 10 cars to compete, not one finishes. The excavators are busy.

The drivers hate it. It's near impossible to conquer and attempting it means a long, torch-lit night excavating kilogrammes of mud out of the truck's vital organs. But the on-track carnage is nothing compared to what's going on up on the hill. The sheer number of teams ensures the event runs deep into the night and, as the evening wears on, madness descends upon the hill-top revellers. Amazingly, there's no real ill-feeling. If this was any other major event, the police would have charged in hours ago. But not here. There are few, if any, arrests. It's fun, nothing more.

Those craving madness enter the throng. Others don't. And for those not keen on a beer-shoe-pint, there are fireworks, dodgem cars, face-painting and kids' rides. "It's all just good fun," says Raelene Paradisi, who along with husband Troy and seven-year-old son, Austin, is on her fifth-straight event. "We call it our 4WD family reunion. We absolutely love it."

Eventually, the night passes with nothing more than some crippling hangovers and thousands of soggy shoes to show for the previous evening's festivities. And things are looking up for team OPW. A series of near-faultless runs has boosted car 05 to the top tier of racers. When the dust finally settles, the team rests on a solid 1,107 points. Impressive, but not enough. The team's finished second to Rock Rash Racing, who finished on 1,121 points. And TopGear's been let into one of motoring's best-kept secrets. It's accessible, honest motorsport at its very best, and as far removed from a media-trained and sanitised professional race series as you can get. In other words, it's wonderful.

Pictures: Thomas Wielecki

This feature first appeared in Top Gear magazine