Here are 15 of the fastest production supercars you've forgotten about

Vencer boss Robert Cobben first stood at the Mulsanne Straight as a teenager in the 1980s, watching sports-prototype cars blitz past at more than 220mph. Needless to say, it had something of an impact.

Indeed, inside this supercharged 6.3-litre V8-powered supercar, you’ll find 622 Hennessey-fettled horsepower’s worth of impact, with full carbon-fibre construction and a six-speed manual gearbox. Oh yes, this is a supercar of the old-school ilk – no traction control, no automated gearboxes, no active this or slip-control that. Just power, lightness and ABS for when you find that all that power and lightness has put you in a situation you’d rather not be in.

Tramontana? That name refers to a wind that brings inclement weather. Or, if we wanted to be a bit more lyrical about things, we could call it the Storm-bringer. Because nothing’s cooler than names that sound like they belong in Conan the Barbarian.

Anywho, you’re probably wondering when we’re going to mention the... er, polarising design. And, unless we’ve missed something, that would be about now. It certainly is a lot to take in. We suppose the most measured thing we can say is that buyers of 870bhp supercars with tandem seating and F1-style suspension aren’t really in the business of being wallflowers, are they?

Technically, this one’s British, as Ascari was founded in Blighty. But then again, it was named for Alberto Ascari, and he was about as British as he was a halibut. And the Ascari KZ1 posted a 1m 20.7s on a damp TG test track, putting it ahead of the times set by the Gallardo Superleggera, Mercedes-McLaren SLR and the 997 GT3 RS in the dry. So, potent enough, you’ll admit.

Much like its Dutch brethren, the Vencer Sarthe, it’s all carbon-fibre, and there’s nothing in the way of electronic nannies to hold your hand and clean up your messes. If you get it wrong, about 500 horsepower’s worth of BMW V8 will happily show you the error of your ways. And then some grass. And possibly the side of someone else’s shed.

The AF8 is a properly serious bit of kit – tubular steel chassis with bonded carbon-fibre sections, and 550 horsepower’s worth of Corvette-sourced LS7 V8. Yep, that’s the 7.0-litre one.

When you factor in there’s just 1,200kg to motivate, it’s little wonder zero to 60 is apparently said and done within 3.5 seconds and 200mph is within reach. And, for anyone who says figures like that are a little old-hat or ho-hum, we defy you to experience either the former or the latter in person and then return the same verdict.

In the 400 GT, the generally weedy PRV V6 made a genuinely gobsmacking 400bhp and 390lb ft. To get there, Venturi compiled a greatest hits version that was so good, it really made the individual albums unnecessary. There were 24-valve heads, as opposed to the standard 12 – courtesy of Peugeot – and the low-compression, high-turbo-pressure combo pioneered by Renault.

It weighed just 1,200kg, so 400 horsepower was more than enough to crest 62mph in less than five seconds and punt past 170mph. Cue the now unavoidable cliche: Mon dieu!

Although they could have stopped at just one, the generous bods at Toyota made two road-legal versions of the 600bhp, 900kg, Dallara-designed GT-One in order to go racing, with road-going concessions extending as far as catalytic converters, raised ride height and a slightly smaller spoiler. If you think about how hard Ferrari worked to turn Alain Prost’s Ferrari 641 into the F50, then consider the Toyota GT-One road car the antithesis of that.

Our favourite part of the ‘yeah... close enough’ homologation rules at the time was the requirement that the cars had luggage space for a ‘standard-size’ suitcase. Toyota merely made the GT-One’s fuel tank large enough to fit the suitcase, then convinced scrutineers that, because the car is inspected without fuel, that this adhered to the rules.

Styling by Ian Callum, engineering by Tom Walkinshaw, a 3.5-litre, 550bhp V8 and provenance from the bonkers (and short-lived) GT1 class of endurance racing? As America’s founding fathers (probably never) said, fetch us a damn quill, because we’re signing right up.

That’s right; not to be outdone by its homegrown rival, Nissan decided to have a full-blown tilt at this whole ‘make a race car and then convince the scrutineers that it’s a road car’ lark. So competition-spec tech like an Xtrac six-speed sequential gearbox and six-piston AP Racing brakes were counterbalanced by leather seats and an actual dashboard. A flawless ruse, we’re sure you’ll agree.

Bristols seemed to have an air of old money about them. Buying a Bristol wasn’t just about fronting up to the Kensington showroom with a pocketful of cash; you had to win the approval of Bristol boss Tony Crook to even get on the list for a new Bristol.

But let’s say you did get into his good graces and got on the list for a Bristol Fighter – what would you get? Well, the 8.0-litre V10 engine from a Dodge Viper, tuned to produce 525bhp and 525lb ft, and fitted into a narrow, British-hedgerow-friendly package. You would also get to sixty miles an hour from rest in about four seconds and, Bristol claimed, a top speed of 210mph. That was probably down to the alleged 0.28 drag coefficient, which is only slightly less slippery than a greased eel. For a more helpful comparison, the Dodge Viper that shared the Fighter’s engine and gearbox has a Cd of 0.45.

Hm. Wouldn’t have minded a go in that one.

The Mosler Raptor (nee: Consulier GTP) was banned from the IMSA series over in the US of A after it consistently beat 911 Turbos and Callaway Corvettes. And to look at it was to wonder if it was a race car or a prototype droid for an upcoming Star Wars flick.

Perhaps it’s fitting, then, that George Lucas himself was the first to receive a production MT900S, the first Mosler that actually looked worthy of a wall poster – black on black, in case you were curious. Although the colour is perhaps less important than the sub-1,100kg kerb weight and 435bhp V8, which combined to run the 0-60 gauntlet in just over three seconds – faster than the contemporaneous Porsche Carrera GT and Ferrari Enzo.

Oh, and in true Mosler fashion, the MT900R racing version won the 2003 Daytona 24 Hour race.

After his racing team started to struggle and eventually withdrew from competition, Jochen Dauer consoled himself by converting a Porsche 962 into a street-legal car. Needless to say, we have deep respect for ideas of such harebrained genius. Apparently, Dauer did such an excellent job converting the 962 he had from his racing days that Porsche got involved. Why? Well, as a road-legal car, it could enter Le Mans in the GT class, rather than the dying Group C. Yep, it’s a race car masquerading as a road car, entered in a modified road-car class in endurance racing. Anyone else wondering if this was the kernel of the idea that eventually culminated in the 911 GT1?

Anywho, as a bona fide race car, the Dauer was the kind of quick that’s difficult to explain without torturing at least one metaphor, but we’ll give it a crack: it won Le Mans outright in 1994 and was promptly banned from the 1995 race. Now think of this kind of performance – Porsche 935 turbo flat six, 0-60 in 2.6 seconds and 252mph top speed – in a road car.

In our book, the XJR-9 is up there with the very greatest things that Jaguar has ever done – winning both the Daytona and Le Mans 24 Hour races, claiming the 1988 WSP Championship and handing Martin Brundle the driver’s championship. So it’s the kind of car that you’d a) assume would pretty much rule the streets and b) pretty much destroy your eardrums. And your assumptions would be pretty much spot on – Brundle himself has said that when the XJR-9 started up, people nearby would jump.

You know how people sometimes talk about ‘a race car for the road’? Jag took that one pretty literally in the case of the XJR-15 – it’s basically an XJR-9, with a bit more room in the cockpit, air con, pop-up headlights and the bare minimum of modifications to make it road legal.

Here we have the Lister Storm: a 208mph supercar with 546bhp and 583lb ft – and four seats. Yep, it was the fastest four-seat supercar for about a decade, thanks in no small part to a race-spec Jaguar V12, bored and stroked to 7.0 litres. It was basically the engine that took the XJR-9 to victory at Le Mans, enlarged by another litre and then wedged in the middle of... well, a wedge.

If you’re thinking, “Boy, that sure looks like a Lamborghini Diablo”, you’re not far off; it’s what Marcello Gandini originally envisaged for the Diablo, before then-owners Chrysler softened and rounded the edges in the final product. And it was put together by ex-Lamborghini staffers after Chrysler took over the company. Underneath you'd find six-litres, 16 pistons, an 8,000rpm redline and 540bhp.

If you’ve been around the traps a bit, you might remember this car being called the Cizeta-Moroder. That’s because famed composer Giorgio Moroder put his time, effort and money into the project to make it a reality. But, as is the way with these things from time to time, bad blood ensued. So it’s just Cizeta now.

Apparently, it’s ‘Lott-ek’, not ‘Low-tech’, but it’s still a bad name. Hey, it happens. But the Sirius – named after the brightest star in the sky – did have something of an ace in the hole: a twin-turbocharged, 6.0-litre V12 that apparently churned out 1,200bhp and 970lb ft. And it’d hold together doing it, because it was a tweaked Mercedes unit from the S600. And any number of tuners have gotten ridiculous figures from Merc engines.

The top speed, depending on gearing, exceeds 400km/h. That’s more than 248mph, or comfortably enough to make you wonder how well the steel space frame chassis has been welded. But that’s really only a problem for one person, given that, as far as we know, just the one Sirius has been built.

What is it, exactly, that makes Britain such a font of low-volume sports cars? Is it our abundance of tracks? Abundance of sheds? Abundance of blokes who are a bit handy with fibreglassing? Someone much cleverer than we are probably has the actual answer to that question, but we’re going to fob that off in favour of the usual British response: because we felt like it.

And this razor can, at least on the surface, be applied to Ultima. Why did Ultima build a record-shattering car, only to offer it in kit form? Felt like it. Why did Ultima build a road-going space-frame racer, then give it those supercar folding doors that are made for Monaco, not maximum attack? Felt like it.

Of course, these aren’t the actual answers to these questions. And, if you found a man with a beard shaggy enough, we’re sure he could give you the answer. Instead, let’s roll out a few of the Ultima GTR’s records, claimed back in 2006: fastest 0-60 and 0-100 times in 2.6 and 5.3 seconds respectively. Nought to 100mph in 5.3 seconds is... heady, to say the least. One hundred back to nought in 3.6 seconds is enough to move the molars to the front of your mouth. And this is without ABS, by the way, because the Ultima GTR doesn’t have it. Or traction control. Or launch control. Or power steering.