Cadillac VR1200 vs Highway Patrol

The bird didn't stand a chance. Clearly not used to anything approaching it at much more than walking pace, it saw the white Camaro ZL1 heaving towards it at well over 300 feet per second, thought, "I'll just eat this worm, then I'll move." And it did. Head first through the left fog light and, now in a zillion pieces, up into the engine compartment at more than 200mph.

While it made a splatter-movie mess of the front of the Camaro, we didn't dwell on the incident for long. We were here to set the highest speed possible, ideally over 220mph, and we had just three hours left to do it. So we wiped down the front of the Chevy, turned it around and gunned it hard back up the hill. 200mph was good, but we knew there was more to come...

And there was. Much more. But before we get to that, let's back up to why we are here in the middle of the Texan countryside on a perfectly smooth, perfectly empty toll road with two monstrously overpowered GM cars, one dead bird, and half of the city's officials perched on a hill with their iPhones and BlackBerrys pointed in our general direction.

Five years ago, the local authority saw that the traffic speeds on Interstate 35, which links Mustang Ridge with Seguin in the south, were slowing like freezing treacle. It couldn't spring for a new road to take some of the volume, so it put the project out to tender. Spanish company Cintra, part of the group that runs Heathrow Airport plus a load of other toll roads around the world, won the contract with US partner Zachry.

One point four billion dollars later, a gleaming 41-mile stretch of new blacktop - that's around $20k per metre - has emerged where there used to be rolling cotton fields. And to pay for it, they charge a toll of $6.17. Nothing too odd there. The interesting bit starts with the road's speed limit. Posted at 85mph for its entire length, it makes the SH-130 not just the fastest road in the US, but also the fastest public road in the western hemisphere.

That's one reason to drive it. The second, and one which is bound to ensure the local law reaps its own tolls from motorists on a regular basis, is that it is coincidentally the fastest way to get to the new Circuit of the Americas, Formula One's newest race venue. And the third reason for being here is that it's all happening on the doorstep of our favourite Texan tuner, Hennessey Performance, who just happens to have two breathed-on cars.

But the real kicker, the don't-tell-me-any-more-I'm-on-my-way fact, is that the local law has said we can go as fast as we like on it for one whole day. Tomorrow, the electronic toll machines will light up, and the police in three counties will have their speed traps ready. But today, the only speed limit is physics, our cars and our courage.

There's not much we can do about changing the science. But we are going to do all we can to beat it with a brace of heavy-haunched road monsters we've imported from the Hennessey workshop. The first is a lightly tuned Camaro ZL1 - an already indecently fast muscle car made faster through the addition of assorted hairy engine parts. The standard car nudges 200mph, but this 755bhp example will stroll past the double ton, for sure.

In any normal situation, the ZL1 would be the fastest car by far. But this isn't a normal day. So the second car is even faster. And not just a bit faster - MUCH faster. On the outside, it looks like a Cadillac CTS-V Coupe wearing a wide bodykit and some extra large rear tyres. Look a little closer, though, and you'll see an extra R. That is significant.

That R means this is one of only 12 Hennessey VR1200s, a rare $295,000 concoction of metal and mayhem that is powered by an almost identical engine to the - cue demonic music - Venom GT. We had planned on bringing one of those, too. But Satan said he was still busy with it, so we left it in its fiery cave and brought the 1,224bhp VR instead. Truth is, the Venom might have been almost too fast for this road.

Because, as empty and speed limit-free as the SH-130 is right now, it's also not the straightest stretch of tarmac in the world. I'd had a look at it on Google Earth before flying out and thought I must be looking at the wrong place. Rather than cutting through the rolling countryside, it follows its contours like a dribble of black molasses.

At 7.3 metres from rumble strip to rumble strip, it's like a British dual carriageway. Lovely if you want a swift and scenic drive on your way to watch some F1. Less lovely if you want to set a new speed record in a 1,224bhp luxury car. It's hard enough keeping your eye in on a dead straight, perfectly level runway at over 200mph. But on a three-mile stretch that features a blind crest, a downhill bend and a large concrete bridge at the end of it, your imagination can kill you before the car's even moved.

I confirmed this fact with a couple of warm-up runs the day before under the watchful eye of the local law's all-too-accurate speed-checking equipment (see ticket, below right). Both cars ran fast and stable on the straights, but required very steady hand-eye coordination through the kink to prevent them from using up all the road and running onto the certain-death rumble strips.

Which is why we brought Brian along. Brian, being a pro racer, shows virtually no sign of self-preservation, and, I suspect, would drive over his own mother if he thought it would add 5mph to his top speed. Imagine The Stig with a face, even though that's clearly not possible, as The Stig's face is a mirrored visor. So it would be your face you'd see, and so... oh dear. This is going wrong. Just imagine a really fast, fearless driver... that's Brian.

And he's setting off on his first run now. Riding shotgun with him in the ZL1, it's clear our hired gun isn't the kind of guy to mess about. He lights up the tyres in the first two gears, then crushes the throttle pedal into the bulkhead as we fly up the hill to the blind crest. By the time we reach it, half a nanosecond later, we are travelling at well over 150mph and still buying speed like it's on sale.

With the road stretching out ahead of us downhill into a right-left kink, the bonnet starts to vibrate and flap about quite alarmingly as we hit 190mph. So much so that I try to focus on the road half a mile ahead to give me a bead on where to aim if the bonnet suddenly flaps up in front of us. Which I know is stupid as I'm not driving. But it still makes me feel better.

Then we hit 200mph at almost the exact time we hit tweetie pie. The car doesn't budge, but my guts do. Just not as fast or as messily as the bird's. Brian is unmoved and still hard on the gas. And he stays on it right up to 205mph, at which point, with the bridge's very permanent concrete stays looming, he decides we've used every last one of the 755 horsepowers and gets out of the throttle. I realise I haven't breathed for the past 10 seconds.

Having got his eye in, it's time for us to Hit the Big Number in the VR1200. Or, rather, just Brian. This run, he informs me, he has to do solo, as my 75kg carcass might shave a mph or two off the speed. I act like I'm disappointed, but the haste with which I accept this fact and get out of the car, belts clanking on the roll cage behind me, might betray that I am actually very relieved.

But there's still tension in the air. Now the sun has been up for a few hours, a nasty crosswind has started to gather pace right across our official test zone. The VR1200 has done a couple of shakedown runs but stopped accelerating completely at 200mph both times (the speed limiter is acting up). Much fiddling of computers and chewing of nails is occurring. There's no way a near-standard ZL1 is going to beat the mighty VR. Is there?

Not if Brian's got anything to do with it. Winding up the car for one last run before the dignitaries go home, he flings the insect-like Cadillac off the line and arrows up the hill. Everyone goes quiet as we listen to him change gears. That's third, that's fourth, that's fifth. He's holding it, holding it, holding it... Then silence. Either the wind is carrying the noise away, or it's blown. Oh God, the suspense...

A couple of long minutes later, the car reappears on the ridge coming towards us. Sounds like it's running OK, and Brian looks as calm as normal. "What happened - did you hit another bird?" someone asks him. "No, but I did hit 220mph," he says. "220? Really?" says Hennessey looking at the VBOX guy, daring him to disagree. "Yep, 220.5mph," he says. Cue one very happy Texan tuner, several hats being thrown in the air and a crowd of dignitaries shaking hands with each other.

I think we may have started a new way of opening roads here. Compared to a mad 220mph car, the traditional ribbon and a pair of giant scissors, like the bird, don't stand a chance, do they?

Words: Pat Devereux
Photography: Drew Phillips

This feature was originally published in the December 2012 issue of Top Gear magazine