Caterham R400

by Pete Wadsworth

Somewhere in the U.S. there is a laboratory with a 2.5 mile-long particle accelerator. A place where men with thick glasses in white coats can fire an electron down a tube at astonishing speeds and watch what happens under different – laboratory defined – circumstances. Such is the rate of acceleration, if you were to fire a gun at the same end and the same time at which the particle begins its journey, the particle would cover the entire 2.5 mile trip to the end of the tube before the bullet had left the barrel of the gun: which is fast. Not as fast as the R400 however, which makes that invisible spec look like it was dragging its heels and kicking a can on the way.

In concept at least, the R400 is a pretty old car, and uses the same basic theory to achieve its impressive pace as Caterham’s versions of the Lotus 7 always have – ample power coupled to a lightweight chassis – but this latest iteration comes with a few key changes. The first of which is the chassis, which is now built by robots – making for much more consistent feel – and is (a surprisingly noticeable) 13 per cent stiffer than the old one. The biggest change to the new Superlight however, is under the bonnet.

After MG Rover went west a couple of years ago, supplies of the venerable K-Series lump – the motor that powered everything from the Roadsport to the R500 Evolution – dried up, and Caterham was forced to find a new supplier. This posed a big problem: the K-Series was a spectacularly light engine and, thanks to its long-bolt construction, a very tough one too. It was only ever designed to be a 1.4, but was bored all the way out to a 250bhp 2.0 litre in the bonkers, £42,000 R500 Evo. In this state of tune, revving to 9,500rpm, the Minister-tuned Rover was about as much of a road engine as the Pope is a Protestant. It was not happy at low revs, kicked hard at 4,500rpm and needed regular rebuilds to stop it turning inside out.

Caterham needed a new approach if they were to continue to eek more performance from the 7 at sensible prices, and this came in the form of Ford’s new Duratec motor – a much cleaner, lower stressed option that was, unbelievably, even lighter than the old ‘K’. Essentially, Caterham Motorsport simply take the 170bhp Duratec motor from the Ford Focus; change the inlet manifold, fit a shouty exhaust, more aggressive cams and remap the ECU, then drop it into the nose of a wide front-track 7 body. These tweaks put it just 30bhp and 40lb/ft shy of the R500 Evolution engine, but to give you some idea of the extra work involved in wringing out those few extra ponies in the old car, an R500 Evolution engine will set you back a staggering £17,500. The lump fitted to the new R400? About five: a far more realistic proposition.

Now the history lesson is over there is one thing I need to make clear: the R400 in the form I had it is not a road car. It had no doors, no windscreen and no roof. Your top gets cold, but thanks to the unbelievable heat soak from the exhaust on your right, the gearbox on your left and the engine in front of you; the soles of your shoes melt, your legs get too hot and your back sweats. Getting in is a faff of epic proportions – it’s a tight squeeze and doing up harnesses every time you want to go out is a pain, you have to wear a helmet if you’re planning on going over 30mph and if you spend any significant amount of time above 70mph you get a headache, unless you wear earplugs – which is also a pain and won’t protect you from the eyeball-rattling buffeting.

But none of this matters once you put your foot down for the first time – this slime green monster is savagely, cataclysmically, brutally quick. Providing you can get the power down, it will hit sixty in a whisker under four seconds and relentlessly pile on speed as you work your way through the six tightly-stacked ratios. At first it felt - not sluggish - but not as quick as I had thought it would; until I figured out that the engine’s inertia is so low, a very quick shift is required to maintain the rate of progress – and how. Once you get the hang of effectively coordinating your left foot with your left hand, changing gears can be done at a pace that feels more like a Quaife sequential than a Ford six-speed with a short-shifter. 0-100 covered in a four-gear thrash that had me laughing like a total idiot, each shift just before the first ‘braaap’ of the limiter barely changing the engine note and never, ever dropping you out of the post-4,500rpm mania.

Arrive at a corner and feel your body pressing against the harness straps as you blip your way (as quickly as your feet will allow) back down the ‘box – immense brakes pulling you up from the scarcely believable speeds you’ve achieved since the last corner, accompanied by a twenty-one-gun salute from the exhaust barely a foot under your right ear. Now experience the joy of unassisted steering as you ease the R400 into the bend. No slack in the controls, a fast rack and massive levels of feel make for huge grins through the twisty stuff – Avon CR500s serving up fantastic grip – you can drive the thing like a big kart.

An interesting new handling characteristic makes itself felt as you set yourself up for the exit: better low down grunt means that if you put your foot down in a bend, the car doesn’t have time to push into understeer before the engine breaks traction with the rear wheels, so the traditional way of driving a Caterham (out of every bend or roundabout with a whiff of opposite lock) becomes a battle with your own self control, as the temptation to just drift around every corner becomes increasingly difficult to resist. It’s just so easy to bring the tail into play, such is the surfeit of power over rear-end grip, and thanks to the alacrity of the steering (and total lack of weight over the rear end) bringing everything back into line is almost as simple – requiring the merest hint of talent and sufficiently quick reactions. If you can exercise a bit of right-foot discipline and ride out a small-angle slide on the throttle, exceptionally rapid progress can be made.

Like the Exige though, such is the involvement in the drive the R400 is fun at pretty much any speed - partly because everything feels so fast - but mainly thanks to the feeling that you can safely extend the car. Limits arrive at (relatively) low speeds so you feel more able to tidy up a mistake before you find yourself going backwards through a field.

It's also amusing to drive through 'suburbia' and watch people being stopped in their tracks by a bright green something being driven by a bloke in a helmet. And it's always a positive reaction: grins from anyone over the age of twelve; stopping and pointing from anyone younger.

Still, the best way to sum up the new R400 is with a single word: intense. Preceded by an adjective of your choice – take your pick from ‘incredibly’ for example, or any number of words that are far too rude to publish on a family website like crash.net. Every one of your senses is bombarded in such an unapologetic way and there is a refreshing and complete lack of an attempt to separate you – as the driver – from how it feels to travel quickly. Everything feels fast, everything that travels under the front and rear wheels is transmitted to you in a totally raw, unpolished way and yet it never feels overwhelming. If driving a Type-R is like running sand through your fingers wearing winter mittens and a Porsche is like doing it with latex gloves, the R400 is the full-on naked digits experience.

You climb out of the R400 at the end of a drive not just wide-eyed, grinning and sweating, but actually feeling invigorated and alive – as if you have truly achieved something as a human being: chemicals coursing through your veins, muscles pumped and brain alert. It’s a visceral experience that, I suspect, would never dim.

Put simply, I want one. Badly.