220mph in the Pagani Huayra prototype

I am sweating nervously in the passenger seat as prototype Huayra Number Three is brimmed with fuel, when a man wanders over and starts jumping up and down on the car's nose. Violent, full-force leaps, again and again. This is not what you want to see a couple of minutes before you're set to ride along on an untested hypercar's maiden voyage towards 220mph.

The two-footed assault on the Huayra's nose is, it transpires, a scientific procedure to check its new front splitter won't fall off and cause a spectacular accident. Satisfied the splitter is stuck on enough to prevent the Huayra becoming a very expensive ground-to-air missile, the man ambles off with a non-committal thumbs up. This does not alleviate my sense of foreboding.

Why is TopGear here? Well, this may sound obvious, but if you're going to sell a 220mph+ car, at some point it has to go over 220mph for the first time. And for all your wind-tunnel testing and computer modelling, that's the point at which you have to let your baby run free and trust that a wheel or, say, a splitter, isn't going to pop off at triple-figure speeds, reducing your priceless prototype and slightly less priceless test driver to a flesh-and-carbon-fibre schnitzel.

Generous souls that they are, the gents at Pagani asked if TG would like to ride shotgun during the almost-ready Huayra's first shot at 220mph on the high-speed ring of a top Secret test Facility that, for reasons of confidentiality and wanting to remain attached to our vital danglies, we cannot name. Suffice it to say that you definitely haven't seen it featured in any recent episodes of TopGear telly.

Davide Testi - chief Pagani test driver, and the man who'll get a very angry letter from my mum if this all goes wrong - hops into the driver's seat, pops down the Huayra's gullwing door and swings us languidly towards the banked, four-lane ring. I rip the gaffer tape off the Huayra's glovebox and delve inside to extract a tiny digital video camera. I am now a felon.

You may have spotted that this feature contains precisely zero photos of a Pagani Huayra charging round a banked ring at obscene speeds. that is because another manufacturer, which may or may not hail from the Stuttgart region of Germany, is testing its own top-secret supercar at the same time and has banned any cameras from inside the proving grounds on pain of efficient teutonic death.

Unfortunately, TopGear only discovered this a couple of hours ago, when, after shooting the prototype Huayra alongside a finished version out on public roads (hey, why have one million-quid hypercar when you can have two?), we cheerily rocked up at the front gates of the top Secret test Facility with a Fiat panda full of shiny camera gear.

This caused a deal of shouting and anger. As the security heavies started to root through his camera kit, photographer Justin - in a rare moment of subtlety - backhanded a tiny video camera into my jacket pocket before being shepherded into a windowless interrogation chamber by a burly man with a pair of rubber gloves and a cruel smile. The camera and I made it behind enemy lines, so it is down to my shoddy videography skills to provide either (a) proof of our glorious high-speed run or (b) vital evidence to the impending coroner's inquest.

We swing out onto the 12-mile bowl, and Testi floors it. The speedometer is rated in kilometres per hour, and 354kph is the magic number: 220mph. In three seconds, we are doing 100kph (62mph), and the Huayra is just getting started. This car has already racked up 300,000 miles in testing; it doesn't feel like it. I watch the needle surge up past 200kph - 124mph - in the time it'd take a hot hatch to hit 62mph. Just as I'm thinking, "Ach, maybe this won't be so dramatic...", Testi tugs the wheel violently to the left. We dive across two lanes and my head slams against the Huayra's window. He tugs the wheel to the right and a whimpering noise emerges from somewhere within my head. "Warming the tyres," he grins. Testi slams the throttle again, and the speedo grabs for the 300kph (186mph) mark.

The acceleration is preposterous - a kerbweight of 1,350kg, over half a ton less than a Veyron, and a twin-turbo V12 churning out 750bhp will do that - but the Huayra's power never seems in danger of overwhelming its rear tyres. That's partly because they're 355-section monsters, but also because the Huayra doles out its power with astonishing linearity. Company boss Horacio Pagani was adamant the AMG-built engine shouldn't simply chase huge horsepower figures with a couple of pumpkin-sized turbos and to hell with the drivability, so commissioned a team of 65 AMG employees to work flat-out on the 6.0 V12, ensuring its responses matched those of a naturally aspirated engine. So far as we can ascertain, they nailed it.

At 300kph, the bonnet unlatches with a clunk, popping up in front of the 'screen. I shriek like a schoolgirl. Davide tuts calmly, swings the Huayra back to the base of the banking and decelerates to crawling speed before bumping the car over the huge cat's eyes. He climbs out, slams the bonnet back down, gives it a decisive thud with the heel of his hand, shrugs and jumps back in the car. Test drivers are an odd breed.

Off again, surging towards 300kph. The accrual of speed is unrelenting, and the ring is disorientatingly featureless. 320kph. I check the back of my right hand, on which I've scribbled a rough kph-to-mph guide. 199mph. We're covering over three miles a minute: at this rate, we could get from London to Edinburgh in under two hours. Still the Huayra remains unperturbed.

Earlier, Davide took me for a hot lap of the Top Secret Test Facility's Top Secret Handling Track in the Huayra. In every other rear-drive hypercar, there's always a squirm from the rears as you dial in full throttle, a shimmy when you get hard on the brakes into a sharp corner as physics protest at being pummelled around. But not in the Huayra - its ability to stay totally bolted to the track was as momentous as its CERN-particle-like acceleration. I have never experienced a car that feels so glued down.

It's all thanks to the Huayra's active aero: atop the bonnet and on the rear deck are two pairs of rudders, each the size of a large hardback book, which the Pagani's microprocessor brain flips independently to keep the car stable in every situation.

For example, in a fast, long, left-hander, the Huayra's left-front paddle pops up to keep the car's nose flat and counter the weight shift to the outside of the curve; under hard braking, the rear paddles will open to stop the car from standing on its nose. It works astonishingly, with the added advantage that the Huayra's suspension can be made more forgiving for everyday driving: out on public roads earlier, the Huayra rode with freakish fluency for a car capable of 220mph. But is it capable of 220mph?

330kph. Two hundred and something. Can't do the maths. Testi flicks an upshift through the paddleshift sequential gearbox. No dual-clutch jobbie here: that would've added around 100kg to the weight. The Huayra gives a throaty huff. From inside, the engine sounds broad and breathy; from outside, as I discovered earlier, it sounds like nothing else on earth. None of the high-pitched, hard-edged shriek of a Ferrari V12 here: the Huayra's soundtrack is a broad, bassy series of sonic booms, a low-frequency salvo that batters you in the chest and leaves a dull ache in your lungs.

340kph. We're north of 210mph. I glance at the Huayra's wing mirror. The speed at which the world is spewing out behind us seems even more absurd than the track being devoured in front. An engineer told me earlier that Mr Pagani insisted that the mirrors must look like the eyes of a beautiful woman. They came back with a dozen designs, each subtly different. Mr Pagani chose, in the engineer's words, "the correct one". And, yes, they do actually look like a woman's eyes. I find this a bit disturbing.

345kph. The increments are getting tougher to come by now. That's 214mph and the noise from outside is deafening now as millions of cubic metres of air batter the front of the Huayra. A sparrow scuds over the windscreen like a cruise missile. Scientists say air assumes the relative density of cold treacle as a car accelerates beyond 200mph, but the Huayra seems to be bending physics, gliding on imperiously. I think how tremendously sad it would be if a tyre went bang now. Not only because the number of ministers capable of pronouncing ‘Huayra' at a funeral must be limited, but because, even in unpainted, gaffer-taped prototype form - hell, especially in unpainted, gaffer-taped prototype form - this is a gorgeous car, taking the Zonda's design cues but launching them into the 21st century. The sleek rear deck moulded over the quad exhausts, the perfectly aligned weave of carbotanium (there is a lot of carbotanium), the jewellish dials: this is a warp-speed masterpiece.

Made of over 4,700 new parts, the Huayra shares not one single bit with the Zonda. Most novel are those huge gullwings, which are not only deliciously extravagant but also make the Huayra far easier to get in and out of than the Zonda, a car that required the flexibility of a malnourished Chinese gymnast to enter or exit gracefully.

But, I wonder, as the needle edges towards 350kph, don't they rather reduce the amount of solid, structural roof above your head? See the Huayra with its doors extending upwards, and it's painfully apparent that only a six-inch wide, inch-deep strip of carbon fibre connects front of car to back. I wonder how much defence this will offer if the Huayra decides to launch itself roof-first into something unyielding. Like, say, Southern Italy.

348kph. That's 216mph. Nearly 100 metres every second. It's getting hot in here. Sweat streams down my back and chest, gathering in a pool somewhere about my perineum. I would like to blame this on the prototype's lack of air-conditioning. It has rather more to do with the fact that we're now into territory only ever visited by a handful of production cars. Unlike James's Veyron Super Sports run at Ehra-Lessien, tackling this bowl isn't simply a case of pointing the wheel straight and clinging on: the ‘neutral speed' at which cars should track straight in the fast lane is 149mph. 200mph+ requires serious left-hand lock.

I glance at Davide. He is a picture of calm. The noise rises again, the horizon envelops the Huayra and, for a fleeting second, I see the speedometer strain past 350kph. I waggle the video camera in front of the dial and, as a Top Secret Security Vehicle swings onto the track, Davide backs off. Did we hit 220mph? Must have been damn close.

Down through the gears, and the real world seems agonisingly slow. Cruising back to the garage at 50mph feels like walking pace. Into the box, and the Pagani engineers confirm that, according to their millimetre-accurate telemetry, the Huayra reached 354kph: 220mph exactly. Casually, they also mention that, given a straight road, it will go a few mph faster: the extra strain placed on the tyres by the circular banking prevented the Huayra hitting its maximum speed.

If any other small company (and Pagani is a small company - even after expanding capacity to 40 Huayras each year, it still has just 53 employees on the books) promised a 220mph hypercar, its maiden high-speed test would be a colon-puckering voyage into the unknown, a mission likely to end with you posted home in a few dozen Jiffy Bags. But there is no car company in the world - hell, any company in the world - with such a pathological obsession with perfection as Pagani.

The Huayra's first trip to 220mph was always destined to go swimmingly, because, as with every element of this car, it was meticulously planned over many years. After nearly a million miles of testing, Pagani's pursuit of perfection is almost complete - the Huayra is set to reach the road in just a couple of months. TopGear will be there, and we can say with certainty that it will be mighty. Whether our poor photographer has escaped his high-security detention centre is rather less certain...

Words: Sam Philip
This feature first appeared in the April 2012 issue of Top Gear magazine