Traditionally, the R400 has long been the forgotten middle child of the Superlight range, offering neither the relative affordability of the R300 nor the ultimate headbanger appeal of the R500. Press reports that less is more when it came to Superlight ownership also did little to further this model's cause. You may have seen the R400 before and wondered why it's now in the news. The casual observer could look at this car and not see anything hugely different but a Caterham anorak would know that this generation R400 is massively different to its predecessor.
The introduction in 2005 of the CSR model marked a step change in the development of the 'Seven' genre. With a beefier chassis and a better engine, the CSR260 was a more grown up, professional feeling car that had exorcised many of the old model's irritations without losing the fun factor. The R400 is even more extreme, the 400 referring to the 400bhp per tonne power-to-weight ratio arrived at with a combination of a 210bhp powerplant and dry weight of just 525kg. Surely 210bhp is small beer when it comes to sports cars though? After all, some Vauxhall Astras better this figure by a good 30bhp. This gives no clue as to the controlled savagery of the R400, a car which will outsprint a Porsche 911 GT3 to 60mph.
The old R400 used a Rover K-Series based powerplant which, for obvious reasons, has been replaced in the latest car by a Cosworth-developed 2.0-litre engine that's now mated to the de Dion chassis. The all-alloy Ford Duratec unit produces a staggering 152lbs ft of torque at just 5,750 rpm. Even at 4,000 rpm, the R400 will transfer an impressive 140lbs ft to the rear axle - that's a full 16 percent more than the outgoing K-Series powered model at the same level.
Mated to a new robot-jig welded chassis, the R400 provides the driver with even more confidence to plant this legendary sportscar into corners. The rigidity of the spaceframe has increased by 12 percent and the greatly reduced flex provides improved grip, improved feedback to the driver and ultimately more speed on the track. The torque characteristics of the R400 powerplant provide instant performance, and more than ever before there is an emphasis on ensuring all the messages from the road are faithfully transmitted to the driver through the suspension and steering.
"The performance of this car can best be described as apocalyptic. It'll leave you shellshocked"
An improved progressive feel to the rear suspension has been achieved through no fewer than 30 changes to the dampers, including improvements by Bilstein to reduce rod to guide friction levels, plus optimisation on the anti-roll bars and road springs. Sitting purposefully on bespoke Avon CR500 tyres and 15" Caterham-designed alloys, the R400 is fitted with a limited slip differential, 6-speed gearbox, wet sump and composite bucket race seats as standard.
For those venturing regularly on the track, the R400 will also feature the option of an exclusive Caterham-designed dry-sump system to provide added protection from oil surges at high speed. Carbon-fibre front cycle wings are matched by a carbon-fibre dash, Momo quick-release steering wheel, road 4-point harness, gear change lights, ventilated front discs and 4-point callipers plus Caterham's legendary Superlight suspension to present an undiluted racetrack inspired package.
Although £25,995 isn't buying you a whole lot of metal, it does net you an enormous amount of capability and the expertise of some of the industry's most talented engineers. It's also cheaper than the outgoing R400 and quicker to boot. The torque response of this engine gives better lugging power if you're caught slightly off optimum revs, with peak power chiming in at 7,600rpm and the top of the torque curve arriving at 6,300rpm where you'll see 150lb/ft. Not huge in absolute terms but significant in terms of torque-to-weight ratio.
On the move, you're astonished by the directness of the steering. Think of a line and the Superlight is on it, the dinner plate sized steering wheel sending the most delicious feedback to the driver. Everything seems alien. You can watch the front suspension doing its stuff and feel the car delicately shifting balance, your body mass perched almost on top of the rear axle. At first, each tentative thrust of the accelerator merely results in gales of disbelieving laughter but confidence quickly builds followed by a feeling of invincibility. Driving a Superlight solely on the road is a little like buying a top line set of thirteen Ping golf clubs and using them exclusively at your local pitch and putt. You're barely scraping the surface of the potential available.
On a track, the Superlight suddenly makes all kinds of sense. The tiny pedal box makes dancing between the pedals a delight and the stubby gear lever can be palmed around the six gears just for the sheer tactility involved. Above all, the handling astonishes. Everything you've heard is true. Tail slides that would usually generate entreaties to your maker in certain other cars become sought at every opportunity in the Superlight. It's the ideal car to learn about the finer points of handling and the art of driving. The light weight of the car also means that it doesn't have a ravenous appetite for tyres nor does it return crippling fuel consumption figures during an enthusiastic session of lapping.
The downside of Caterham ownership is the impracticality. Loiter around the showroom in Caterham (strangely enough) and you'll encounter numerous hardy types who run one as their only car, dismissing as fey any complaints that it's a bit uncompromising. The doors fitted to the Superlight only barely justify the description, being vinyl flaps that affix with a popper and to which the door mirrors are attached. The rear view can therefore be a little fuzzy, the best tactic being to travel faster than any posterior hazard.
The Superlight R400 has created a real buzz among Caterham enthusiasts and one of the most fervent fans of the marque is rock star Chris Rea, a long standing Seven owner. "When I heard about plans to introduce a replacement for the old R400, I simply had to have one!" said Rea. "The combination of Cosworth power and the Series 3 chassis delivers an adrenaline rush and a level of performance that I cannot resist." Even the Road To Hell is probably pretty god fun if you've strapped on a Superlight R400.