The most powerful car in the world

Tom Stewart gets behind the wheel of an American beast that sacrifices much polish and most refinements in the name of speed

If you want to drive seriously fast you're spoilt for choice at present – at least in terms of the machinery available, if not the roads to do it on....

There's the 253mph Bugatti Veyron, the 250mph-plus Koenigsegg CCXR and the forthcoming 270mph Bristol Fighter T, which will be restricted to 225mph. There's also the Hennessey Venom Viper with a claimed but unverified top speed of 255mph.

Choices, choices, choices... and that's without considering the SSC Ultimate Aero TT, the world's most powerful production car, ever. Boasting a gargantuan 1,183bhp, the small, little-known Washington State-based company Shelby Supercars claims a top speed capability of 273mph. In tests earlier this year on a closed section of Nevada highway the SSC managed 230mph in the two miles available, but had the originally intended 12-mile site not been hit by snow, the Veyron could have been humbled.

With strikingly rich paint, its all-carbon-composite bodywork looks like something from the mid 1990s, with noticeable variances in some panel gaps. There are echoes of Pagani Zonda at the front and Lamborghini Diablo at the sides, while at the rear function has priority over form.

There's little impressive inside as design, fit, finish and detailing falls far short of the current supercar norm. On the plus side it's easy enough to climb in and out of, the leather seats are supportive, it's reasonably spacious with ample headroom, and the driving position is fine apart from the front wheel arch intruding into the footwell,

By now you may be wondering just how the TT's not insignificant price of $550,000 (£270,000) (ex-factory) can be justified, but in the small roof console there's a large red button, and when you press it this car's purpose becomes immediately apparent. Something resembling a controlled nuclear explosion takes place as the modified, twin-turbo 6,348cc Corvette pushrod V8 bursts into life. This start-up extravaganza only lasts a second or three before the engine settles into a loud offbeat V8 burble.

Despite the TT's massive torque it's eager either to either set off like a dragster, or stall. (I understand that this particular car is to soon receive a replacement clutch, which may help.) And despite SSC's brochure claiming the TT's rack and pinion steering is assisted, I didn't feel the slightest hint of assistance. Manoeuvring at parking speeds requires strong arms and a firm grip on the wheel. But once rolling the SSC is easy enough to drive, with a precise gearchange and direct, accurate steering.

The SSC grips tenaciously and its nose goes precisely where you point it. The steel-tube chassis feels suitably rigid but I can only guess how the car might behave when driven hard on a track. With so much power, rear wheel drive and no electronic traction aids, considerable expertise, and prudence,

would be necessary. Straight-ahead visibility is fine, but the SSC's massive A-pillars can be a hindrance. Rear vision is effectively zero, save for the door mirrors and a rear-facing camera with pop-out screen in the radio/stereo/satnav unit. The adjustable suspension was set somewhere between firm and rock-hard and so the ride was correspondingly unforgiving. Driving one or more of those super-wide Michelins over cats-eyes sent loud staccato bangs and solid thumps directly into the cabin. At legal speeds the exhaust is quiet enough to allow conversation, but lifting off the throttle causes an almighty cacophony from the twin-turbo wastegates.

And then there's the car's throttle response, which is like nothing I've experienced before. With just the slightest pressure on the pedal the car accelerates briskly. With just a tiny bit more it surges forward with near-terrifying urgency, and all the while there's a sense of the immense, almost infinite power lying in reserve.

Prod the throttle with anything less than caution and those huge rear Michelins will spin. Fortunately, despite the massive urge available at any speed in almost any gear, the TT can potter along in fifth or even sixth gear without drivetrain snatch.

While it's no surprise that the TT can serve up salt-flats-shrinking speed, the brakes on this particular car are something of a mystery. The brochure states that eight-piston calipers should be fitted at the front, but this one had four-piston calipers. Pedal pressure required was inordinately high, with almost no feel or power (I still await an official explanation).

This all leads to the ultimate question concerning the Ultimate Aero TT. Who would want one? You could argue that $550,000, or about £335,000 by the time it's on the road in the UK, is a ludicrous sum of money for a left-hand-drive car with no heritage, a slightly dated appearance, zero luggage capacity, build quality on a par with a 1980s TVR, all the luxury of a small Malaysian hatchback and nothing to indicate that it won't depreciate faster than you could set light to it.

Conversely, it's more powerful, more exclusive and potentially faster than a Veyron, while costing less than half as much. And since when did all-American muscle have to dress up like posh European aristocracy? Some loud paint, serious wheels and an even louder V8 is all it really needs, and that's what it's got, in unprecedented abundance.

Neither argument is wrong, so I guess owners will be few, and keener on driving at almost four times the national speed limit than most of us.

Specifications

Engine type: all-alloy 16-valve V8 twin turbo

Displacement: 6,348 cc (387.2 cu in)

Power: 1,183 bhp (1,199 PS) @ 6,950rpm (7,200rpm redline)

Torque: 1,094 lb/ft (1,484 Nm) @ 6,150 rpm

Transmission: six-speed manual, rear wheel drive

0-60 mph: 2.78 secs

Standing 1/4 mile: 9.9 secs @ 144mph, 60-0mph: 31.4 metres (103 ft)

Top speed: 273 mph (calculated, see text)

Chassis: steel tube space frame

Body: carbon fibre composite, flat undertray with venturi tunnels

Drag coefficient: 0.357

Brakes: 14-inch vented, cross-drilled discs, 8-piston* calipers (front), 6-piston* (rear), (*see text)

Suspension: double wishbone (front), upper rocker arm, lower wishbone (rear) remote reservoir, adjustable Penske dampers, coil-over springs, anti-roll bar

Wheels: forged, 3-piece alloy, 19 x 9.5" (front), 20 x 13" (rear)

Tyres: Michelin Pilot Sport PS2, 235/35 19 (front), 335/30 20 (rear)

Price: $550,000 ex-factory, approx £335,000 on the road in UK www.sscautos.com