What is it?
The Caterham R600 is a racing car for those who think the R300, currently top of the racing Sevens tree, isn't fast enough. It seems a lot of competitors think that of the highly tuned, naturally-aspirated R300. But instead of using the even more highly tuned, road-only R500, the new, race-only R600 (keep up) has a supercharger strapped to its 2.0-litre Ford Duratec so that it makes 275bhp.
To say it's fast would be something of an understatement.
But that's also true of the R500, which makes an unshabby 263bhp, so why a new model rather than racing with R500s? Because, says Caterham, the speed gains of the R500 are marginal given the blurry revs it needs, while consistently running near 9000rpm brings a reliability compromise.
The R600 – whose peak power arrvives at 7500rpm – is less stressed and torquier, with 200lb ft instead of the 500's 177.
That means the R600 will pootle at 20mph for car-to-car tracking photos without a care in the world. Most racing cars would be spitting, complaining and grumbling at the nasty, low-revolution chore, but the R600 is a happy bunny. Caterham has not announced plans to make a road version, but its race models usually adopt number plates once they've been track proven. The supercharged Duratec feels flexible enough already.
And the rest of the hardware? Well, that's a touch less adaptable for the road. Caterham wanted the R600 to be much quicker than the R300; about four seconds per typical lap is the ambition. So there are Bilstein race dampers, a full roll cage, a Sadev sequential six-speed gearbox (allowing clutchless upshifts), a limited-slip differential and, when the championship starts this spring, it'll use slick Avon tyres.
What is it like?
Today, at a dank Blyton Park, Caterham's demonstrator is fitted with full race wets, which is just as well. Like in a supercharged Ariel Atom, the R600 is the sort of car in which you think you've reached the end of the throttle's travel, only to find there's rather more to come. And, as in a supercharged Atom, the urge – which is both irresistible and relentless – arrives instantly.
In these conditions, traction is not an R600 strong point, but on slicks during a typical race season, it'll be extraordinary. Twenty R600's all heading towards Paddock Hill at full chat? It'll be one of club racing's most enteraining moments.
Even in more slippery conditions like today it's impressive. Grip is strong. The steering is heavy, super-direct and accurate. Throttle response sharp and linear, and the brakes powerful.
The R600's handling balance – because it's easier to get heat into the rear tyres than the fronts today – errs towards a touch of understeer, which can be neutralised on the way into corners with a trailed brake or, better still, with a boot of throttle.
Then the R600 displays the handling tendencies of the best Sevens: utterly faithful, benign and communicative, allowing you to stay on the gas and ride out the slide. Within two laps I was happy to exit any of Blyton's corners crossed up.
There aren't many lightweight road cars, let alone race cars, in which I'd so quickly do that happily.
Doing it with 20 other R600s around would keep you on your toes, mind. They asked for a faster Caterham Seven to race. My goodness, they're about to get one.
Should I buy one?
Yes, unless you want to drive in on the road. In which case, you’ll have to put up with the pedestrian R500 for now. Exceptionally strong power delivery, terrific gearbox and strong brakes make the R600 one of the fastest road-based racers around, with all the adjustability that we love about the Seven.
Caterham Seven R600
Price £44,995; Top speed 153mph; 0-60mph 2.6sec; Economy na; CO2 na; Kerb weight 550kg; Engine 4 cyls in line, 1999cc, supercharged, petrol; Power 275bhp at 7500rpm; Torque 200lb ft at 6500rpm; Gearbox 6-spd sequential manual