A tour of Hennessey’s workshop

John Hennessey. You've heard the name, seen his 1244bhp Venom GT, and watched it go 270.49mph to claim the Not-Guinness-Certified-But-Still-Chuffing-Quick record for the fastest production car in the world.

Earlier this week, the Texan tuning king exclusively showed Top Gear his latest road-legal land rocket: the Venom F5, a V8 twin-turbo evolution of the Venom GT briefed to shove the Bugatti Veyron Super Sport out of the record books and replace it with a big fat chunk of American horsepower.

But even though the Venom is the car grabbing the headlines, it's actually just a sliver of what makes up the Hennessey brand.

Pictures: Rowan Horncastle

So on a recent trip to the Lone Star State, TG figured it'd be good to drop by Hennessey HQ. And considering that Texas is known for its love of all things BIG, we were shocked that base camp for the upcoming Venom F5 is a small (for Texas) corrugated shed flanking Interstate 10 just west of Houston.

Where Bugatti's Veyron is carefully constructed in the "Atelier", an automotive art gallery-cum-workshop in Molsheim, France, John's workshop is the antithesis. It's attached to Lonestar Motorsports Park, Hennessey's own drag strip and proving ground, complete with lo-fi single-track road course more suited to Tewkesbury than Texas.

We arrive to the aroma of burnouts and brisket lingering in the air. The previous day, Hennessey held the annual ‘TX2K', a two day dyno and drag event (complete with bikini contest) that pulls in over 10,000 people.

"In Texas there's a big interest in fast cars," John says. "There's a lot of NOS and big boost guys. They all come here, use our facilities and drag it out."

Outside the shop there's a snaking line of brand new Corvettes, Camaros, CTS-Vs, Mustangs, Vipers and Ford Raptors from around the world, all waiting to have their wick turned up.

Inside the automotive abattoir, things get yet more insane. A Ferrari 430 Scud, McLaren MP4-12C and Ferrari 458 sit suspended six feet in the air, wheels dangling and guts spilled. Catching a glimpse of two Precision Turbos sagging under the rear bumper of the Scud, it's clear that these aren't in for frivolous Vanessa Feltz-style gastric band surgery. No, we're witnessing full-on triple-heart bypass surgery.

"The owner of that," John says, pointing to the disemboweled McLaren, "wants it to be as fast as a P1 but with no electric motors and torque fill. We don't know if it's possible, but we can sure as hell find out."

That's the attitude that got John here in the first place. Sitting on his father's knee, steering the family's prized '64 GTO as a baby, John was bitten by the petrolhead bug early. But it wasn't until the early Nineties that tuning became his passion.

In his twenties John bought a Mitsubishi 3000GT, a car that cemented his love for four wheels and would later carve out his future. After tinkering with it in his backyard, John spent a summer cruising round the US, ticking off the petrolhead bucket list.

In May he competed in Nevada's Silver State Classic, then road-tripped straight to Colorado to run the plucky 400bhp Mitsu up the dirt at Pikes Peak. Then, for the finale, that August John drove it to Bonneville Salt Flats, returning to Texas with a ticket in the glovebox confirming a record-setting 173mph run.

That 3000GT was the harbinger for a career in horsepower. Seeing companies like RUF, John realised there was business in tuning cars. Having stockpiled some money from his previous employment in environmental cleanup, John set up Hennessey Performance Engineering.

Now, as we stand in a shop with 20 full service bays, 16 vehicles on lifts, a welding and fabrication shop, an 800 Twin-Turbo VelociRaptor on one dyno, and a 1000bhp-plus CTS-V sleeper wagon on another, it's quite clear that things have come a long way since then.

It was tuning Vipers that Hennessey gained recognition - most notably cooking up a 1000bhp version of the muscle coupe that got from 100-200mph four seconds quicker than a Bugatti Veyron. But, despite the tuning success, John wanted to build his own car: the Venom GT.

The matte black prototype currently resides in the shop's reception. And just like homeless men with great radio voices, or fiercely addictive K-pop music videos, the success of the Venom has the internet's virality to thank.

When the car was nothing more than a print out on an A4 piece of paper, the designs were leaked online, and quickly worked their way across the globe on the digital infobahn. Later that week John received a phone call from a minted car enthusiast in the Middle East who wanted the car so much that he offered to front the initial development and build.

However, the Venom was nearly stillborn. Tragically the person who commissioned the first Venom GT then died in a helicopter crash, stalling its development. As a memorial, the family told John to continue with the car. Call it a very, very fast cenotaph.

The Venom GT has come a long way since then, culminating in the 270mph car that's sat on the workshop floor, fresh from its run at the Kennedy Space Center.

We ask to drive it. Oddly, John's first reaction head to the window and check the weather. "It's overcast," he says. "Now, traction has to be right in this car. So you can drive it if you want, but I'd really recommend you do it when it's sunny."

Suitably terrified of binning quite literally the fastest car in the world and having to blame it on ‘light cloudiness', we decide to cherry-pick something else.

"Thousand horsepower cars are a small percentage of what we do," John says as we work our way through the stockpile of muscle cars scattered around. "We may build around 20 thousand horsepower cars a year, but our bread and butter are the ones you can drive every day. Ones you can run on pump gas, be sure they're reliable and easy enough to drive you can let your other half drive it with no worries."

With that, he hands over the keys to a HPE700 package Chevrolet Camaro ZL1.

Now, the ZL1 is already the top of the Camaro food chain, but John's reworked it from 580bhp to 707bhp. With ported cylinder heads, an upgraded camshaft, additional cold-air intakes, long tube headers, high-flow cats, new pulleys to up the boost, a retuned ECU and a modified heat exchanger for better charge-air cooling, that's a 200mph-plus potential daily driver to deal with. It also comes with a three year, 36,000 mile warranty.

Turn the key and the ZL1 barks brutally into life. With its newly cammed engine, at idle it kicks like a six-month foetus. It's also loud. Very loud. So loud I ponder whether the new headers and exhaust are actually attached. This makes it instantly intimidating, yet incredibly intoxicating.

But it's all very familiar once on the move. Although the pictures above may prove otherwise, with those big, fat sticky tyres, getting the power down wasn't an issue. When it hooks together, the whole car rears up as the supercharger produces an addictive, looped Wilhelm scream, the car bucking and shimmying between gears. Before you know it there are big triple figure speeds on the head-up display.

Before we choke ourselves to death on acrid tyre smoke, or end up in Texas' finest penitentiary, we return the keys to John. One last question: what's Hennessey's mission statement, its reason to exist?

"We're here to make fast cars go faster," is John's answer. "It's really that simple."