Caterham

Caterham 7

Related models : Caterham 21
Picture Gallery: Nil	Related topics: Lotus Seven classic
Versions included here: General, Superlight R, Superlight R500, CSR, Superlight R500 (2008)

Launched in 1957, Seven was the first road-going Lotus. Although Lotus has officially ceased its production in 1973, the production right was succeeded by Caterham and it is still in production now and even at a rate of 1,000 per year. If you do not count the Brazilian built Beetle, Seven would be the oldest car you can buy.

In those days, its tubular steel spaceframe chassis was an advanced design, just like the aluminium chassis of Elise in today. As it is as light as 575kg, the Rover K-series engines can push the car from zero to 60mph in just 6sec. Top speed is let down by the poor aerodynamics, since its creator Colin Chapman was more concerned the acceleration and cornering stability.

Seven is a minimalist. It got no radio, no air-con, no glove box, no door and no roof. But the advantage is the optimal weight saving, which transfer to the super steering response and adjustability in corner. No car could provide more pure driving fun.

Caterham 7 Superlight R

Imagine a car with 190hp, weighing at only 470kg, no roof, no windscreen, no equipment, exposed wheels....you might have been thinking a Formula 3 racing car, no, it is a road car, Caterham Superlight R.

Superlight R is almost a racing car, in fact, its theory is every bit the same as racing car. Power comes from the race-tuned Rover 1.8 litres K series 16 valves, with 190hp at nearly 8,000 rpm and 150lbft peak torque. This engine is so racy that it can't pass emission and noise regulations, so import to US is infeasible. In Europe, people can buy this car in kits form to avoid violating the law.

All panels are aluminium, without glass and soft roof so that the kerb weight is reduced to record low. This further improve the already excellent handling of the car, while 0-60 is also benefited - my estimation is 4 seconds flat.

Recently, Autocar magazine performed a test in Nurburgring track with this car against Porsche new 911 Carrera (300hp), Ruf 911 CTR2 (520hp) and Nissan Skyline GTR (280hp, 4wd, 4ws), the lap time is amazingly found as follows :

Caterham Superlight R .......... 8 min 6.2 sec
Ruf 911 CTR2 ....................... 8 min 15.0 sec
Nissan Skyline GTR .............. 8 min 28.1 sec
Porsche 911 Carrera ............. 8 min 38.4 sec

Benefited by the light weight and superbly balanced chassis, the Superlight R ran considerably faster than others in bends, although it lost a lot of time in fighting with drag in straights. Road tester found it handles very much better than others, it is virtually a racing car.

Nurburgring is usually regarded as the best place to test a car's real world performance - it has high speed straights as well as a hundred bends with different speeds. The Superlight R broke the track record for non-modified road car, so, maybe we can call it "the fastest car in the world". Hard to accept ? Ferrari F50, McLaren F1, Nismo Skyline 400R and Porsche 911 GT1 (this is really a racing car!) might be faster, but until they are tested in Nurburgring, the Caterham still remains to be the King.

Caterham 7 R500

Pressurized by arch-rival Westfield’s FW400, Caterham has upgraded its racy Seven Superlight R into the R500, the name implies 500 horsepower per ton. Weighing in 460kg, the R500 is 10kg lighter than its predecessor but still yet to match the 400kg of the FW400, which has full-carbon fiber chassis instead of Caterham’s traditional tubular space frame. However, modifications to the VHPD engine squeezed another 40hp, that makes a total of 230hp. No wonder in terms of power to weight ratio the Caterham beats the Westfield.

Weight saving is by means of lighter material used. In this aspect, magnesium is the best material to replace aluminium in engine sump and wheel hubs; Apart from the nose cone and wings, carbon fibre now spreads to the wind deflector (which is used instead of windscreen to further reduce weight), rear view mirrors, sill protectors, dashboard and bucket seats. The instrument reading is implemented by digital LCD like racing cars.

Then comes the power. The 190hp VHPD is already a Very High Performance Derivative of the Rover K-series (as its name implies). The 1.8-litre unit is now further enhanced by forged steel crankshaft and con-rods, Cosworth-made lightweight forged pistons, larger ports, higher lift camshafts and a touring-car-styled roller barrel throttle instead of conventional butterfly throttle. The roller barrel reduces pumping loss by its lack of air resistance. As a result, it pumps out 230hp at 8,600rpm and 155 lbft at 7,200rpm. Given sufficient run-in, it can spin to the 9,200rpm red line ! even more revvy and more efficient than Honda’s mighty S2000. Admittedly, the Caterham complies with looser emission requirements because it falls into the low-volume type approval scheme.

It is a surprise to find that the R500’s engine is more tractable than the Superlight R. Not just Caterham’s boss said so but journalists also found so. At low speed it is not as difficult to drive as the R. At high speed it displays superior performance. Caterham sees this car as a true successor to the Seven JPE of 1992. If you don’t remember, you are reminded that the mighty JPE was powered by a 250hp engine derived from Opel’s 2-litre 16V, weighed 540kg and still holds the British 0-100mph-0 record of 12.41 seconds. To challenge the JPE’s record, a perfect launch is require, so Caterham has given the R500 a traction control. Without the electronics, you had better to up shift with a lightening action, otherwise wheelspin will spoil the chance.

Although claimed to be capable of taking just 3.4 sec to 60mph, the roofless machine is primarily designed to eat bends on race tracks, so are its radial tyres. Extra care must be taken to prevent over press the throttle in low gear corners, as the surge of power will induce oversteer. Always remember it is a 500hp/ton supercar.

In late '99, it set a new lap record of Nurburgring in 7 min 55.21 sec, marginally faster than the previous record holder Porsche 911GT3.

Seven CSR

It has been more than 5 years since I last wrote about Caterham Seven, but compare with the 48 years history of the car, this is nothing. Unbelievably, almost half a century after Colin Chapman put the Seven into production, the car received its first thorough redesign.

Externally, the Seven CSR260 still looks like a classic Seven, but underneath the skin is a new story. Its tubular spaceframe chassis is derived from the previous wider body SV (which provides more room than traditional Seven), with 25% increase of torsional rigidity. All suspensions are new – the long-serving non-independent de-Dion rear axle is finally replaced with modern double-wishbone. It gives far better wheel control and ride quality, lifting both handling and ride. The front suspensions are also converted to double-wishbone, whose springs and dampers are moved to inboard, operated by pushrods, in order to improve aerodynamics.

You may notice the wheels are now much bigger and wider, almost like Formula 3 wheels. They grow by 2 inches in diameter to 15 inches, and wear 255/40 tires at the rear, compare to the 215/50 tires used in the previous Seven R500. These are half-slick tires developed specially by Avon.

In the past decade the Seven was powered by Rover K-series engines. In the previous R500 Evo, the hottest K-series engine was so highly tuned that it could produce 250 horsepower from 2.0 litres of displacement. The downside was lack of mid-range torque and reliability. Because of this, Caterham turned to engine expert Cosworth for a new engine. (Coincidence or not, this also saved Caterham when MG Rover bankrupted.)

Unbelievably, the Cosworth 2.3-litre 16V engine was developed based on a Ford commercial van engine. However, virtually everything has been changed. It has bespoke cylinder head, intake manifolds and exhaust, valves, camshafts, pistons, forged connecting rods, aluminum block, dry sump lubrication...

There are two stages of tune for the engine. The cheaper CSR200 produces 200 horsepower at 7000 rpm and 165 lbft at 5750 rpm. The hotter CSR260 has lightweight forged pistons and racing-style roller barrel throttle (which reduces air resistance) to produce 260 horsepower at 7500 rpm and 200 lbft of torque at 6200 rpm. Caterham says the CSR260 can sprint to 60 mph in 3.1 second, beating a McLaren F1. Its 155 mph top speed also sets new standard for the Seven.

On the road, the first thing you notice is how much more supple the CSR ride. Thanks to the extensive tuning work spent by Caterham, they found a perfect damping setting – on B-roads it rides even better than Lotus Elise. The independent double-wishbone suspensions have much longer travel and therefore absorb bumps with ease. They also keep the tires perpendicular to the road regardless of bumps, thus generate more grip and predictable handling at all conditions.

The CSR is 100kg heavier than R500 Evo, but at 570 kg it is still 300 kg lighter than a Lotus Elise 111R. No wonder it steers, accelerates and stops with incomparable responsiveness. The tiny steering wheel transmits streams of information in the same way as racing cars. This is not only the fastest, but also the best handling and best riding Caterham Seven ever produced. The only thing you have to consider is price: a factory built CSR260 costs £36,500. That almost matches a Porsche Boxster S.

Superlight R500 (2008)

New R500 has many things mirroring the old one, including its ability to thrill its drivers...

9 years ago Caterham produced the famous Superlight R500, a Seven with a power-to-weight ratio of 500hp per ton. It could beat any supercars of its days in racing tracks, no kidding. Time seems frozen for the following years. Today, what appears in front of us is again a Superlight R500, again with 500 horsepower per ton, virtually the same appearance and construction. In order to make it as light as possible, Caterham forgos the more modern CSR chassis and adopts the older Series 3 chassis, which has a narrower body, non-independent rear suspensions by means of de Dion axle and Watts link and smaller 13-inch wheels. In other words, everything sounds like the original R500.

What really distinguishes the new car is engine - a Caterham-tuned Ford Duratec 2.0-liter 16V engine. It is the best compromise between the old Rover K-Series 1.8 engine (whose power band was too peaky) and the CSR's long-stroke Duratec 2.3-liter engine (which is not that smooth and free-revving). Again, all the high-performance components - in particular roller barrel throttle bodies - contribute to very high efficiency. Max power is 263 hp at 8500 rpm, 30 up from the original R500. Max torque is 177 lb-ft at 7200 rpm, 22 up. There is much stronger mid-range torque so that the driver no longer needs to squeeze the engine so hard.

Partly due to the heavier engine, the new R500 is 46 kg heavier than the old car. However, at 506 kg it is still comfortably lighter than CSR, let alone any other sports cars on the market. Like CSR, it employs carbon-fiber nose cone, wings and dashboard. Seats are made of Kelvar. Thinner gauge aluminum body panels complete the lightweight package.

Due to the lack of aerodynamic consideration, the R500 could top only 150 mph on highway. However, on twisty roads I can't think of any cars capable of beating it. Should you work hard, it will accelerate from rest to 60 mph in 2.88 seconds. Through bends, its superiority is even more obvious. Low center of gravity, racing-style adjustable suspensions, semi-slick Avon CR500 rubbers and strong braking contribute to immense cornering prowess. Its lightness and agility translate to incomparable speed and driving excitement. I am glad that the new R500 not only shares the same looks and power-to-weight figure with the old car, but also the same talent to thrill its drivers.

Specifications

Model	7 Superlight R500	7 CSR260	7 Superlight R500 (new)
Layout	Front-engined, Rwd	Front-engined, Rwd	Front-engined, Rwd
L / W / H / WB (mm)	3380 / 1575 / - / 2225	3300 / 1685 / 1140 / 2315	3300 / 1575 / 800 / 2225
Engine	Inline-4, dohc, 4v/cyl.	Inline-4, dohc, 4v/cyl.	Inline-4, dohc, 4v/cyl.
Capacity	1796 cc	2261 cc	1999 cc
Power	230 hp / 8600 rpm	260 hp / 7500 rpm	263 hp / 8500 rpm
Torque	155 lbft / 7200 rpm	200 lbft / 6200 rpm	177 lbft / 7200 rpm
Transmission	6M	6M	6M
Suspension (F/R)	strut / de Dion axle	all: double-wishbone	double-wishbone / de Dion axle
Tyres (F/R)	185/55R13 / 215/50R13	195/45R15 / 255/40R15	N/A
Weight	460 kg	570 kg	506 kg
Top speed	145 mph (est)	155 mph (c)	150 mph (c)
0-60 mph	3.4 sec*	3.1 (c) / 3.3* sec	2.9 sec (c)
0-100 mph	8.1 sec*	7.6 sec*	N/A
AutoZine's rating	Discontinued	Not rated	Not rated
See illustration to spec.	Figures tested by: * Autocar