Caterham Seven

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Caterham Seven
Manufacturer Caterham Cars
Production 1973 — Present
Predecessor Lotus Seven
Class Sports car
Body style(s) open 2 seat
See also: Lotus Seven
Main article: Caterham Cars

The Caterham Seven (or Caterham 7) is a small sports car produced by Caterham Cars in the United Kingdom. It is based on the Lotus Seven, a lightweight sports car sold in kit and pre-built form by Lotus Cars, from the late 1950s to the early 1970s. After Lotus ended production of the Lotus Seven, in 1972, Caterham bought the rights to the design, and today make both kits and fully assembled cars. 2007 marked the 50th year of production of the Lotus/Caterham 7.

The Caterham Seven is a small, lightweight, two-seater sports car renowned for its performance and handling. Various other manufacturers offer a sports car in a similar basic configuration, but Caterham owns various legal rights to the Lotus Seven design and name. The company has taken legal action in the past in order to protect those rights. The modern Seven is based on the Series 3 Lotus Seven, though Caterham have developed it to the point that no part is the same as on the original Lotus.

Contents

[edit] History

Today’s Caterham cars have a blend of traditional styling and modern components. They can trace their lineage directly to an original 1950s-era Colin Chapman design. Chapman, a Royal Air Force pilot, studied structural engineering and went on to become one of the great innovators in motorsports design.

After the war Chapman became highly successful race driver and then founded Lotus Engineering Ltd. in 1952. Chapman’s vision of light, powerful cars and performance suspensions guided much of his development work with the basic design philosophy of 'adding lightness'. The Lotus 7, which is almost identical to today's cars debuted at the 1957 Earl’s Court Motor Show in London.

The first Lotus 7s were priced at £1,036 including purchase tax but it cost only £536 in kit form as no purchase tax was required. It weighed only 725 lb. Fast and responsive, the Lotus 7 was one of Chapman’s masterworks, an advanced machine that surpassed the earlier Lotus 6 as a vehicle that could perform beautifully on the track and be driven legally on the road. The 7’s basic (and much copied) design was to stand the test of time, continuing in its popularity for the ensuing 50 years.

The 7’s evolution continued when, in 1973, Caterham Cars obtained manufacturing rights from Lotus to enable Lotus to move away from 'kit cars' and produce more up-market sports cars. Caterham renamed the car the "Super 7" – an apt name, as it was becoming clear that the car’s fundamental design was nearly impossible to improve having the right balance of strength and handling with a very light weight. Caterham's original offering was the series 4, since that was the current production car at the time of the handover from Lotus. Unfortunately Caterham suffered numerous supply problems with the Series 4 and by the middle of 1974 they had reverted to the Series 3, which was perceived to have better sales potential anyway. The modern day Roadsports and Superlights (in "narrow-bodied chassis" form) are the direct descendants of this car and therefore of the original Lotus 7.

[edit] Chassis and suspension

As with the Lotus Six before it, the original Lotus 7 utilised an extremely light space-frame chassis with stressed aluminium body panels. Although the chassis has had numerous modifications to strengthen it and accommodate the various engine and suspension setups (and to try and find more cockpit space for the occupants), this basic formula has remained essentially the same throughout the seven's life (with the exception of the dead-end Series 4, which used steel for the cockpit and engine bay and glassfibre for the bodywork). Early cars used a live rear axle, initially from various Fords, later from the Morris Ital. De Dion rear suspension was introduced in the mid-1980's and both geometries were on offer until 2002 when the live-axle option was phased out. The modern Superlight employs adjustable double-wishbone suspension with front anti-roll bar and a de-dion rear axle, located by an A-frame and Watt's linkage.

The Caterham 7 range was based exclusively on this "series 3" chassis until 2000, when the SV (Series V, or Special Vehicle) chassis was released, aimed at accommodating the increasing number of prospective buyers who could not fit comfortably in the series 3 cockpit. The SV chassis offers an extra 110 mm of width across the cockpit, at a cost of 25 kg of extra weight, and both chassis sizes are available today in Roadsport and Superlight variants.[1] The SV chassis subsequently provided the basic dimensions for the Caterham CSR. The suspension was completely redesigned, bringing the front suspension inboard, using pushrods, and replacing the De-Dion rear axle with a lighter, fully independent, double-wishbone layout with new coil/damper units. Additional chassis modifications resulted in a 25% increase in torsional stiffness.[2] The CSR was released in October 2004, with a Cosworth Duratech engine and is currently available from the factory in either 200 bhp (150 kW) or 260 bhp (194 kW) form.

[edit] Engines

Early cars used the Lotus Twin Cam engine (subsequently manufactured by Vegantune), followed by Ford cross flow engines.[3] The first Cosworth BDRs appeared around 1983, in 1600 cc 140 bhp (104 kW) form, followed by 1700 cc 150 bhp (112 kW) versions three years later. By 1990 the top of the range engine had become the 2 litre Vauxhall HPC, as fitted to the Vauxhall Calibra, putting out 165—175 bhp. In 1993 Caterham created the JPE special edition (named for formula one driver Jonathan Palmer) by using a 2 litre Vauxhall Touring Car engine, putting out around 250 bhp (186 kW) and reducing weight to around 530 kg by such measures as removing the windscreen in favour of an aeroscreen. The JPE was quoted at 0-60 mph times of around 3.5 seconds and, with Jonathan Palmer at the wheel, set a 0-100 mph-0 record of 12.6 seconds. Around 1997 the cross flow range was replaced by 8v and 16v Vauxhall units which, in various guises lived on until the end of the VX-powered Caterham Classic, in 2002.

The Rover K-series made its appearance in 1991, initially as the 1.4 litre engine from the Metro GTi. This engine became the backbone of the range for the next 15 years. The 1.6 litre k-series appeared in 1996 and the 1.8 litre a year later. 1996 also saw the addition of the 'Superlight' range, a range that successfully focussed initially on reducing weight and subsequently on bespoke tuning of the k-series to ever-higher outputs. Weight was saved by removing the spare wheel (and carrier), carpets, heater and often the windscreen (replaced with an aeroscreen), hood and doors. Lightweight "Tillet" GRP seats were usually fitted along with carbon-fibre front wings and nosecone (note however that items such as heaters and windscreens could still be specified by the Superlight customer if they so wanted). Wide-track suspension was added to the superlight, increasing the track at the front to match that at the back. The later Superlight-R offered the dry-sumped VHPD (Very High Performance Derivative) variant on the 1.8 litre k-series. Output was now up to around 180 bhp (134 kW), in a car that now weighed as little as 490 kg. Three years later Caterham took the same concept to a new level and created the iconic Superlight R500, still based on the Rover 1.8 litre k-series but now tuned (by Minister Racing Engines) to around 230 bhp (172 kW) at 8,600 rpm in a car weighing just 460 kg. The R500 was initially available in kit-form, but quickly became a factory-build only item. Quoted performance figures still make impressive reading; 0-100 mph in 8.2 seconds (although EVO magazine quotes 8.8 seconds[4]). Perhaps unsurprisingly, such a stressed engine required frequent "refreshing" in order to keep it on the road and a series of engine revisions was undertaken throughout the R500's life in order to increase reliability. This culminated in 2004 with perhaps the most extreme production Caterham of all; the R500 EVO was bored out by Minister to 1,998 cc and delivered 250 bhp (186 kW). At £42,000, the R500 EVO was hardly a sales success - it is widely believed that just three examples were sold. It did however succeed in setting a series of performance car benchmarks several of which last to this day; the 0-100 mph-0 record was set at 10.73 seconds (in second place was a Ferrari Enzo costing ten times as much) and, until the end of 2006 it remained the fastest production car timed by EVO magazine around the Bedford Autodrome West Circuit, ahead of a Porsche Carrera GT. Only the Radical SR3 1300 has subsequently posted a faster time than the R500 EVO.[5]

After the demise of Rover and Powertrain, Caterham started the process of phasing out the Rover k-series engine and replacing them with Ford engines; the Sigma engine for Roadsports and the 2.0 litre and 2.3 litre Duratec engines for the more powerful Superlight and CSR ranges. Although Caterham's website suggests that there are a few models (such as the Superlight R300) still available with a k-series engine, this migration is largely complete.

Caterham have had something of a tentative relationship with the installation of motorbike engines into their cars. In 2000 the Honda CBR1100 engine was installed into a 430 kg superlight chassis to create the Caterham Blackbird, delivering 170 bhp (127 kW) at 10,750 rpm (although just 92 lb·ft (125 N·m) of maximum torque). The Blackbird offered near R500 performance for rather less money (Top Gear quote 0-60 of 3.7 seconds and a top speed of 143 mph (230 km/h) at a new cost of £25,750).[6] In 2001 a Honda Fireblade engine was offered in a live-axle chassis, via James Whiting of Ashford, Middlesex. Quoted power was 128 bhp (95 kW) at 10,500 rpm. Both of these models have ceased production. There has also been at least one installation of the RST-V8, created by Moto Power; a 2 litre, 40 valve 340 bhp (254 kW) V8 made from a pair of motorcycle engines joined at the crank. An early, pre-production review of the car/engine combination exists on the EVO website.[7] . In Feb 2008, the "Caterham Seven Levante" was announced, featuring a supercharged version the RST-V8, offering over 500bhp, installed in a modified Caterham chassis, with bespoke bodywork. Made by RS Performamce (described in the press release as "Caterham's new performance arm"), the Levante is intended to be a limited run of 8 cars at a cost of £115,000 each.[8]

[edit] Racing

Caterham 7 on track at Spa
Caterham 7 on track at Spa

The Lotus 7 was conceived by Chapman as a car to be raced. Whilst still a prototype, in September 1957, it was raced at the Brighton Speed Trials[9] and by the end of 1958 Graham Hill was winning races with the Coventry Climax-engined 'Super Seven'[10] The car has had a strong racing history throughout its life under both Lotus and Caterham stewardship. Amongst the marques more famous races was victory in the Nelson Ledges 24-hour race in Ohio when, against a field including works teams from Honda and Mazda, a four-man team from Caterham (including both Jez Coates and Robert Nearn) won by seven laps (after 990 laps) in a modified Vauxhall HPC.

After dominating open class races for decades Caterham Super 7 Racing, a one-make championship for Caterhams, was begun in 1986. Caterham 7 races have since expanded to include club and competitive races in the United Kingdom, continental Europe, Canada, the United States and Asia. In 1995 the Caterham Academy, a novices-only format, was introduced in the UK. For £16,995 (2007 price), entrants get a modified Roadsport kit (although a factory-built option is available for extra cost) with a sealed 120 bhp (89 kW) engine and 5-speed gearbox. Having completed the ARDS license qualification, the season then consists of four sprints followed by four circuit races. The Academy is designed as the first step in a well-established chain of Caterham race formats (Graduates, Super Grads, Roadsports, Caterham Challenge and then on to European circuit formats).[11]

The car was banned from racing in the USA in the 1960s, as being "Too fast to race" and again in the UK in the 1970s for the same reasons, which prompted Caterham Cars boss Graham Nearn to produce 'T' shirts with "Caterham Seven, the car that's "Too Fast to Race. .." .Both bans were later lifted. In 2002 an R400 won its class (and came 11th overall out of 200 starters) at the Nürburgring 24-hour race by 10 laps, ahead of competition that included Porsche and BMW racecars, leading, once again, to a ban on entry in subsequent years.[12]

[edit] Current range

Caterham 7 Roadsport SV
Caterham 7 Roadsport SV

The existing range provided by Caterham Cars comprises a mixture of chassis types (the traditional narrow-bodied 'Series 3' chassis, the wider SV chassis and the CSR chassis), of engines (k-series engines, which are now being phased out, Ford Duratec engines for the more powerful variants and Ford Sigma engines for the lower-powered models) and of models (Classic, Roadsport, Superlight, CSR, in ascending order of price). All are available either factory-built or as a self-build kit. It is anticipated that the k-series engine will shortly disappear from the lineup, resulting in an all Ford engine range.

[edit] Classic

The Classic represents the entry-level offering from Caterham. It is available only in the Series 3 chassis size and, as standard, comes with a 1.4 litre k-series engine (whilst available) and five-speed gearbox. There is no heater, hood or spare wheel carrier as standard (although all these can be added as options). In all other respects it is the same as a Roadsport. Quoted performance with the 1.4 litre engine is 0-60 in 6.5 seconds and a top speed of 110 mph (180 km/h).

[edit] Roadsport

The Roadsport is available in both S3 and SV chassis sizes and is more or less a Classic with a more powerful engine and a few more extras as standard; heater, hood and spare wheel/carrier are all standard as are carpets. At the moment the engine options encompass both Rover k-series (160 bhp) and Ford Sigma (125 bhp or 150 bhp) options, although the k-series is expected to disappear from the options list once supplies are exhausted. Suspension is the same as for the classic; double-wishbone and anti-roll bar at the front and de dion axle located by an A-frame at the rear.

[edit] Superlight

The Superlight is available in both S3 and SV chassis sizes. The list of standard equipment reflects the Superlight's bias to track work; Wide-track front suspension, 6 speed gearbox, Carbon fibre dashboard and front wings, GRP aeroscreen and seats, racing harness, removable steering wheel. Quoted weight for the Superlight is about 50 kg less than the Roadsport, due in part to the lack of a spare wheel and carrier. Engine options again are something of a temporary mix of incoming Ford Sigma (150 bhp) and outgoing Rover k-series (160 bhp) for the R300. Both the R400 and R500 use the 2 litre variant of Ford Cosworth Duratec engine, in different states of tune. The R400 is quoted at 210bhp, the R500 at 263bhp. With the recent launch of the R500 (April 2008), Caterham made available the options of a sequential gearbox and launch control. Quoted performance for the R500 is 0-60 in 2.88 seconds and a top speed of 150mph.

[edit] CSR

The CSR represents the top of the range and in some respects can be considered a separate model. It has its own chassis, suspension and interior and is available with either 2 litre (200 bhp) or 2.3 litre (260 bhp) Ford Cosworth Duratec engines. Quoted performance for the CSR260 is 0-60 in 3.1 seconds and a top speed of 155 mph (249 km/h). There is no home-build option; the factory supply the finished car.

In 2006, Caterham introduced the CSR Superlight. Based on the CSR260, this model adds a ‘Superlight’ lightweight specification to the CSR, further extending the CSR260’s already epic performance envelope. The 2.3 litre Cosworth-powered Caterham CSR260 Superlight brings all the performance credentials associated with its stablemate; performance is quoted as a 0-60 mph time of 3.1 seconds and a top speed of 155 mph (249 km/h). The Superlight swaps the windscreen, carpet, heater and weather gear on the standard car for a limited slip differential and a quicker steering rack. Twenty five kilos lighter than the standard CSR260, this model variant also adds distinctive Superlight styling to the exterior, including a wind deflector, a carbon fibre dashboard and wings, a black powder coated cockpit and a quick-release MOMO steering wheel. Of particular note are ‘Dynamic Suspensions’ Damper units developed by specialist Multimatic for the car. The damper units lend the already capable CSR a further edge in terms of handling and cornering performance. It features the same 2.3 litre (260 bhp) engine as the CSR260, but weighs only 550 kg and has a power-to-weight ratio of 472 bhp (352 kW)-per-tonne.

[edit] 50th Anniversary editions

Caterham have celebrated the 50th year of production with a couple of special edition "50th Anniversary" paint options. In addition, as part of the 50th anniversary celebrations in early June 2007, they showcased the X330 concept car. Based on the CSR, the X330 employs a supercharged version of the Duratech engine to produce 330 bhp (246 kW). The use of lighter-gauge steel and of carbon fibre instead of GRP further improves the power to weight ratio. Caterham say that they have no plans to put this car into production.[13]

[edit] Notes

  • In the anime éX-Driver, one of the three lead characters, Souichi Sugano, drives a yellow Caterham Super Seven JPE. One of their opponents, Todo, uses a black Super Seven to battle the eX-Drivers.
  • In the anime Gate Keepers, recurring character Jim Skylark drives a modified version of the Super Seven with the Lotus badge and license plate "AEGIS 07" in his debut episode, racing Shun Ukiya in his modified Toyota Sport 800 (Toyota Publica) on the freeweay, and gets busted by cops.
  • In the anime You're Under Arrest, Ken Nakajima's mother Sena was once a road racer driving a yellow Caterham Seven.

[edit] References

  1. ^ See http://www.caterham.co.uk/showroom/index.htm
  2. ^ "Caterham Sevens, from conception to CSR", by Chris Rees
  3. ^ This paragraph largely draws from Chris Rees' book "Caterham Sevens from conception to CSR", published by MRP, ISBN 1-899870-61-X,
  4. ^ EVO Magazine, Issue 100, January 2007. Published by Dennis Publishing Limited
  5. ^ EVO Magazine, Issue 100, January 2007. Published by Dennis Publishing Limited
  6. ^ See http://www.topgear.com/drives/G1/A0/roadtests/10/01.html
  7. ^ See http://www.evo.co.uk/carreviews/evocarreviews/49734/caterham_rst_v8.html
  8. ^ See http://www.rsperformance.co.uk
  9. ^ Caterham Sevens, from conception to CSR by Chris Rees
  10. ^ The Lotus Book, by William Taylor, Published by Coterie Press. ISBN 1-902351-13-4
  11. ^ See http://www.caterhamracing.com
  12. ^ Caterham Cars, press release 16/April/2003, also see http://adac.24h-rennen.de/portals/24h/extern/ResultDB/live.asp
  13. ^ See http://www.autocar.co.uk/News/NewsArticle/AllCars/225910/

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