TWIN TEST. Ariel Atom 3.5 vs Caterham 420R

April 04, 2017

Does the latest high-tech supercar hold the key to driving euphoria? Or might the answer be something a little…simpler? We find out with two well-established giants of the lightweight sports car world, Caterham and Ariel.

  • Check out the original post on HERE and pdf coverage from evo Middle East HERE

 EnginePowerTorque0-100kphTop speedWeightPrice
Ariel Atom 3.5Inline-4cyl, supercharged, 1998cc310bhp @ 8600rpm229lb ft @ 7200 rpm2.7 secs250kph (limited)520kg (596bhp/ton)$47,200
Caterham 420RInline 4cyl, 1999cc210bhp @ 7600rpm150lb ft @ 6300rpm3.8 secs219kph560kg (375bhp/ton)$49,820

The noise from the airbox over my right shoulder drills itself so vehemently into my skull that I’m genuinely concerned about permanent damage. It’s extraordinary, a high-pitched wail of pure, unadulterated anger that makes me yearn for the safe confines of a helmet, and at the same time, anything but. Do I pull over to salvage what remains of my eardrums? Jog on.

The semi-frameless polycarbonate windscreen arcing towards me is the only reference point I have for the front end, given the aggressive banking of the sports seat I find myself in: I may as well be sitting on the front axle for all I can see of the wheels and the dual wishbone suspension pummelling away either side of the nose cone. In my peripheral vision, a blue light on the digital LCD dashboard flashes from orange to blue, signalling another gear change, the supercharged falsetto shriek taking a microscopic breather before filling its lungs once more.

In my hands, the suede steering wheel jimmies from left to right as the wheels and dampers telegraph the undulating road surface through the competition steering rack. I have no idea how fast I am going – my peripheral vision can’t quite register the triple figures on the digital speedometer – but I’ve just snatched fourth, so chances are I’m going at a fair lick. Every sane fibre in my body is screaming at me to calm down, ease down, “for the love of God man, stop!”, especially since the Atom’s owner – evo Middle Eastreader, Dr Mohammed Al Suwaini – is standing on the side-lines watching my progress. My right foot ignores all of this, as does the side of my brain that allows another maniacal blast of laughter to escape my lips. evo Ed-in-C Bassam was right. The Ariel Atom 3.5 is, unquestionably, the most mental thing I have ever driven.

And yet, it’s so simple.

Let’s be honest, driver-assistance technologies by their very nature are actually quite dull. Outrageously complex and developed by men and women with the kind of brain circumference my meagre grey matter can only dream of, absolutely. But when it comes to the actual thrill of driving, in both concept and execution, these systems are just plain boring.

Take for instance the McLaren 720S recently launched at the Geneva Motor Show about which Woking’s marketing elite lauded new and improved steps with the new carbon fibre MonoCell II, the hydraulically-operated air brake, and the double-clutch automatic gearbox, through which gear changes have been sharpened to within fractions of milliseconds. Each of which, we’re assured, will set new benchmarks for ‘the thrill of driving’, though even my sceptical self can’t deny that.

And yet the Ariel Atom 3.5 and the Caterham 420R with us today, two of the finest handling machines you can buy for less than a fifth of the McLaren’s asking price, have none of these. Indeed, their construction is almost rudimentary by comparison.

“Every sane fibre in my body is screaming at me to calm down, ease down, ‘for the love of God man, stop!’ “

Power for the Caterham comes not from a 4-litre biturbo V8 but from the 1999c Ford Duratec four-cylinder, the Ariel’s 1998cc example having been lifted from the relatively humble Honda Civic Type-R. The Caterham’s now legendarily simplistic – and lightweight – louvered bodywork has been built atop essentially the same steel frame chassis since the late 1950s. The more ornate steel underpinning of the Atom meanwhile wraps itself around the cockpit as an elegantly straightforward steel lattice, while standard-fit carbon fibre over the 15in wheels, air intake and front canopy are about it as far as bodywork goes.

At each corner of the Caterham, there are 15in ‘Orcus’ alloys clad with Avon ZZS rubber as part of the optional ‘R’ pack trimmings. These continue on the inside with a carbon fibre dashboard, a leather transmission tunnel topper, a 12V power socket, and a miniature Momo steering wheel. At the back, there’s a roll-cage behind the two mounted leather seats, local dealers Al Futtaim having decided against the composite race seats for the sake of increased ‘comfort’, but keeping the four-point race harness. And….yeah, that’s about it, if you don’t count the carbon fibre rear mudguards. No torque vectoring or performance Pirelli P-Zeroes in–sight.

The more ‘opulent’ Ariel meanwhile adds an optional Jackson racing supercharger to hike the Atom’s base 245bhp to a loftier 310bhp, and torque from 165lb ft to 229lb ft. Mohammed’s example also houses an LCD digital display in front of the driver, plus a very visible mounting rig on the passenger side for right-hand drive markets. There’s revised three-bulb LED headlights – a welcome change to the ‘bug-eyed’ examples from the first Atom – and an ‘aerofoil’ rear spoiler for even more downforce. Compare that with the Caterham’s analogue speedo and odometer with a couple of gauges set aside for oil and water temperature. Plus, removable doors on our test model. Seriously, nothing spells ‘simple fun’ quite like a Caterham.

Even before Mohammed and I have started our run then, we’re already in agreement: the 420’s small rear wheels look lost in those massive rear wheel arches but it’s hardly a deal-breaker; the Atom’s more visceral looks certainly don’t dent the old school charm of the Caterham; and while a day in a McLaren 720S is undoubtedly on the bucket list – hint, hint Woking – can these two British track weapons offer just as scintillating a driving experience? Of course. But which one gets the nod?

 EnginePowerTorque0-100kphTop speedWeightPrice
Ariel Atom 3.5Inline-4cyl, supercharged, 1998cc310bhp @ 8600rpm229lb ft @ 7200 rpm2.7 secs250kph (limited)520kg (596bhp/ton)$47,200
Caterham 420RInline 4cyl, 1999cc210bhp @ 7600rpm150lb ft @ 6300rpm3.8 secs219kph560kg (375bhp/ton)$49,820

Admittedly, in terms of outright pace, the 310bhp Ariel has the upper hand. At 560kg and 520kg respectively, both the 420R and the Atom 3.5 offer the kind of performance that makes one weak at the knees, but the more equally-rivalled Caterham 620R is not set to arrive in the Middle East until at least early next year. The 210bhp 420R is thus outgunned on the sprint to 100kph by over a second – 3.8 secs to 2.7 secs – and overall top speed, the Caterham nailing 220kph as the Ariel tips a (limited) 250kph.

“The supercharger was actually optioned by the previous owner, but I’m really glad he did,” Mohammed explains. “I remember watching [Jeremy] Clarkson’s video, and thinking, ‘yes, that’. The acceleration of this thing is just brutal, unlike anything I’d ever experienced before.” A point the good doctor demonstrates by jumping in, firing the starter button on the dashboard, and launching away from a startled, and now-dust coated, Hari, who’s busy taking a reference shot of the exhaust pipes at the time. After some brief faffing with the immobiliser, I’m away in the 420R, which, there’s little doubt, is also seriously rapid.

Even with just a modicum extra of power and torque over the similarly engined 360 – 30bhp and 7lb ft, if you must quibble – the 420R feels like an entirely different animal to its naturally aspirated sibling. From the initial, immediate pick-up that causes even the grippy Avons to snatch briefly, there’s a raw potency at work, the wide torque band causing those now dry-sumped four-cylinders to eat their way through the revs to the 7600rpm limit with gusto. Short ratios through the five-speed manual gearbox aid almost outrageously large momentum build instantly. I’m left with the impression, as the revs hurtle like kamikaze banshees to the redline, that I’m constantly reaching for the next gear through the short shift lever, give or take a bit of time to get used to the clutch pedal’s surprisingly high biting point. Mohammed and the Ariel’s high-mounted exhaust tips are already out of sight, but this is still a seriously strong engine, thriving particularly in the high revs.

It’s not the speed of the Caterham though that reaches for my eruption button. It’s the handling. Even with the ferocity of the rear-biased power delivery, there hasn’t been the arm-flailing locks of oversteer I’d expected. With the 420, Caterham has focused more on track-performance, transferring the suspension componentry, brakes and stickier Avons from its headlining 620R accordingly, the latter of which can feel quite spiky on initial start-up as grip is lost and regained rapidly. Once up to performance temperature though, the difference is striking. Lift off the throttle mid-corner and the rear axle will break with progression into gentle flicks, rather than unhinged, animalistic snatches. Part of this is down to Avon’s semi-slicks, which dig deep into the asphalt under turn-in, the rears accordingly locking onto line with only the assurance of your right foot allowing them to break free.

“There’s a raw potency at work, the wide torque band causing those now dry-sumped four-cylinders to ear their way through the revs.”

The heavily weighted steering requires a huge amount of physicality at slower speeds, but the intricate feedback offered through that small Momo wheel has never been anything less than exceptional. The chassis, archaic though it may be, is beautifully balanced, and there isn’t even a hint of understeer. The brakes meanwhile offer superbly judged pedal weight and progression that, hard as you try, will not snatch. A dash more lumbar support from the admittedly very comfy leather seats wouldn’t go amiss, and the vibrations sent through the lightweight doors make the wing mirrors next to useless, but I care very little about this. There’s nothing to rely on but my own skill, and it’s no wonder that the Caterham remains among the most immersive driving experiences you can have.

Further up, gentleman that he is, Mohammed has resisted the temptation to jump from his Atom, lean against the skeletal steel frame, and look smug. While I’ve been pratting around and attempting to break the Caterham’s monumental traction, the Ariel has simply got on with the process of covering an insane distance in a time most mortal minds can barely fathom. Don’t be under any misapprehension; the supercharged Ariel Atom 3.5 is stupidly, heroically, eye-wateringly quick. And Mohammed is allowing evo to take this, one of only three road-legal Atoms in the Middle East, for a drive. “Just go for it.”

Save for a new Mugen gear knob, the only ‘comfort’ Mohammed has afforded himself is the carbon fibre body panels running down each flank as a primitive form of insulation, though the tubular chassis is still visible from the driver’s seat. The process of getting in is much the same as the Caterham: right leg in, balance weight on the right arm, left leg in and shuffle arse cheeks until you realise you’re sitting on the four-point racing harness. As an ‘occasion’ though, there’s something different about this.

“There’s nothing to rely on but my own skill. It’s no wonder Caterham remains among the most immersive driving experiences you can have.”

In the 420R the bonnet stretches way out in front of me as I sit vertically in the leather seats mounted just in front of the rear axle. In the Ariel I’m almost reclining in the more canted carbon-backed sport seat, front axle – seemingly – just beneath my knees, and the Honda four-cylinder poking me in the shoulder blades. By my right knee is the long-stalked Mugen sic-speed gear lever, the linkages on full display just ahead of the master switch for the ignition. If I cock my head to the side, avoiding the chassis-mounted handbrake by my left elbow as I do, I can see the aluminium cross-drilled pedals – another weight-saving device – that are mounted more ‘aerodynamically’ and certainly closer together than in the Caterham: for a moment, I worry I’m going to ride the clutch under braking.

Everything is cool and metallic. It’s like I’ve dropped into the cabin of a small Le Mans prototype, which makes the switchgear for indicators, high beams, hazard warning lights, and, baffling, windscreen wipers on the pseudo-flat-bottomed steering wheel all the more bizarre.

A twist of the master switch and the LED display springs into life. The anger of Honda’s four-cylinders has yet to show itself, although I can feel the chassis twitching beneath me with each rumble. Interestingly, there are few cars I’ve been in that offer a greater sense of exposure than the Atom, and yet, the high shoulder line of the chassis, plus the low mounted sport seats actually makes me feel less vulnerable than the Caterham.

Then I press the throttle…

 EnginePowerTorque0-100kphTop speedWeightPrice
Ariel Atom 3.5Inline-4cyl, supercharged, 1998cc310bhp @ 8600rpm229lb ft @ 7200 rpm2.7 secs250kph (limited)520kg (596bhp/ton)$47,200
Caterham 420RInline 4cyl, 1999cc210bhp @ 7600rpm150lb ft @ 6300rpm3.8 secs219kph560kg (375bhp/ton)$49,820

Mohammed, now in the 420R, disappears immediately in the dashboard-mounted screen that acts as my rear-view mirror (there’s no way a conventionally mounted one would be able to see around the airbox). Having left my sensible trousers on for my first run, I’ve only depressed the throttle about halfway, but the travel and the precision thereof has already proven incredible: as my confidence begins to build over the ensuing half an hour, my right foot begins to explore the immediacy yet subtly intuitive nature of the throttle more and more, the supercharger emitting a whine akin to a bench saw cutting through metal as I do so. Then comes the explosion.

Pure adrenaline ignites in every part of my body as I open the throttle fully. The soundtrack attacks my ears, the savage turn of speed as the Atom leaps onto its toes and starts sprinting is unlike anything, I have ever experienced, on four wheel or otherwise. The side panels hold back little of the wind that smashes its way into my chest, the Atom consuming each passing metre with neither turbo lag nor fatigue holding it back.

This thing is utterly, utterly insane. It’s almost a disappointment when the first corner hoves into view. Almost.

Much like the acceleration, the immediacy under turn-in catches me completely off-guard, an inadvertent mid-corner lift making me all the more appreciative of the Atom’s colossal traction. Not wanting to fart around with the setup too much, Mohammed admits that the Ariel’s overly urgent handling caused him to swap his stock 15in alloys for larger examples, front and rear. The wider rubber does mean the rear is considerably less intimidating now, which is just as well, given that the only thing preventing a spin are my reflexes behind the wheel.

Fortunately the terrific rate of response through the helm, plus superb feedback from the front wheels, means that, once I’ve relaxed and start feeding the front end into the turns rather than throwing it, those sharp edges of threatening oversteer begin to fade. There is no understeer at all, but I’m less pre-possessed to steer the Atom on the throttle than I was in the Caterham: in the 420R, despite the raw speed, you’re encouraged to let the innate playfulness in the chassis take control; in the Atom, you get steadily braver with the throttle, hustling the front end by the scruff of the neck as if daring it to snap at you. It’s visceral. Intense.

“Then comes the explosion. Pure adrenaline ignites in every part of my body as I open the throttle fully.”

In a bizarre parallel to the frenzied madness under acceleration, the front end is so progressive in its movements yet so immediate in its response, that you’re unlikely to find a wilder handling performance machine this side of a superbike. Rarely has the thrill of driving been so visceral.

So infected am I with THAT adrenaline rush that I almost double my allotted time behind the wheel in scant regard of the dropping fuel level, and even when I do calm down and pull to a stop, I motion to Mohammed that I’m still not going to get out. He smiles, clearly amused by the grin that threatens to crack my jaw in half. “Yeah. That’s how it gets you.”

The power and speed delivery in the Caterham 420 is raw and potent. But this? This is savage, ethereal, and brutal, threatening to fill every fibre of your body with shock, awe, and, most importantly, adrenaline when you put the hammer down. It doesn’t matter that the gear lever is mounted slightly too far forward, that the shifts through the enormous stalk and extra light clutch pedal are less intuitive than the Caterham’s short shift setup. It doesn’t matter that, arguably, the Atom’s more grounded – though superbly balanced – chassis is less playful than the slightly more rear-biased Caterham 420R. It’s not even a concern that the Ariel’s edgier and hyper-sensitive steering at high speeds is less confidence-building than in the 420R. You won’t care about any of that when the Atom’s supercharged whine attempts to bullet through your temple, the explosive forward momentum causing your internal organs to slam together and puree themselves. No question, through the corners, the Atom is impressive, but it’s the adrenaline-pumping savagery under acceleration that will get you. Every. Single. Time.

I’m not going to insult your intelligence by questioning whether these niche British marques offer the thrill of driving akin to a high-tech supercar. That the Caterham 420R remains one of the most engaging, playful and rewarding performance machines you can buy for less than $50K is beyond doubt, the 420R mixing lightweight agility together with ‘edge’ and spectacular bursts of aggressive acceleration in stunning harmony. Few things are more fun and sensational to spend an afternoon with than a Caterham. Except an Ariel Atom.


*Images courtesy of Harisanker.S and Awesome Group


Ariel Atom 3.5 (Tech specs)

Engine: Inline-4cyl, supercharged, 1998cc

Power: 310bhp @ 8600rpm

Torque: 229lb ft @ 7200 rpm

Transmission: Six-speed manual, rear-wheel drive

Suspension: Double unequal length fabricated wishbones (front and rear)

Brakes: Ventilated, 290mm (front and rear)

Wheels: 16in (front), 17in (rear)

Tyres: 225/45 R16 (front), 275/40 ZR17 (rear)

Weight: 520kg

Power-to-weight: 596bhp/ton

0-100kph: 2.7 secs

Top speed: 250kph (limited)

Price: $47,200

Caterham 420R (Tech specs)

Engine: Inline 4cyl, 1999cc

Power: 210bhp @ 7600rpm

Torque: 150lb ft @ 6300rpm

Transmission: Five-speed manual, rear-wheel drive

Suspension: Unequal length double wishbones (front);

De-dion semi-independent suspension with radius arms (rear)

Brakes: Twin circuit split front-rear

Wheels: 15in (front and rear)

Tyres:195/45 R15 Avon (front and rear)

Weight: 560kg

Power-to-weight: 375bhp/ton

0-100kph: 3.8 secs

Top speed: 219kph

Price: $49,820