Caterham CSR

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CSR 200/260
Manufacturer:	Caterham Cars Ltd
Engine:	2.3 liter inline four Ford Duratec tuned by Cosworth; 200 or 260 bhp
Transmission:	Standard 5-speed with 200 model, Custom Caterham close ratio 6-speed with 260 model
Suspension:	Adjustable front and rear double wishbone, inboard, F-1 style front suspension, front adjustable anti-roll bar
Steering:	Rack and pinion
Brakes:	254 mm (10") discs, front vented, 4 piston front calipers
Safety:	Roll-over bar, no airbags, optional honeycomb strengthening panels
Wheelbase:	2315 mm
Length:	3300 mm
Width:	1685 mm
Height:	1015 mm (hood down), 1140 mm (hood up)
Turning radius:	11 m
Ride height:	100 mm
Front track:	1505 mm
Rear track:	1465 mm
Curb weight:	575 kg (1268 lbs)
Fuel economy:	10.22 liters / 100 km (23 mpg)

The Caterham CSR is the latest model from sports car manufacturer Caterham. The CSR has been improved upon significantly from previous models, while still retaining the basic look of the Super Seven. The CSR has two engine options, both based on the same Duratec block. The only difference is the amount of tuning done by Cosworth. The entry level engine produces 200 bhp, with a 0-60 mph time of 3.7 seconds. The upgraded engine produces 260 bhp, with a 0-60 mph time of 3.1 seconds and a top speed of 155 mph.^[1]

Contents 1 Performance 1.1 Handling and braking 1.2 Low-end acceleration 1.3 High-speed problems 1.4 Cosworth engine 1.4.1 260 model 1.4.2 200 model 1.5 Other features 2 Improvements 2.1 Chassis 2.2 Suspension 2.3 Aerodynamics 3 Criticism 3.1 Ease of driving 3.2 Safety 3.3 Security 4 Review 5 Purchasing and licensing 5.1 In the UK 5.2 In the United States 6 Facts and figures 6.1 Engine specifications 6.2 Transmission specifications 6.3 Performance specifications 6.4 Vehicle specifications 7 See also 8 References 9 External links

[edit] Performance

The CSR represents the most radical redesign since the introduction of the Seven in its 48-year history. The CSR is the subject of numerous improvements over previous models (see below), though it still retains the main aesthetics of Caterhams.

[edit] Handling and braking

While slightly heavier than other Caterhams, the CSR still upholds Colin Chapman's philosophy of "add lightness."^[2] Weighing only 575 kg (1268 lbs), the CSR has excellent handling, and compared to many other performance vehicles and is extremely agile. On the skidpad, the Caterham outperforms many supercars. It's 1.05 lateral G's beats the 2007 Porsche 997 Turbo, which handled .94 G's as well and the Ferrari F50 which handled 1.03 G's and the Ferrari Enzo which handled 1.01 G's.^[3][4][5] In Braking tests, the CSR performs well. From 70 mph to a complete stop, the CSR took 140 feet. The 997 Turbo, stopping from 60 mph took 99 feet.^[3] The Ferrari F50 performed well, stopping from 60 mph in 119 feet.^[4] For comparison, an average car takes 315 feet to completely stop from 70 mph and Formula One cars can stop in 56 feet from 62 mph (100km/h).^[6][7]

[edit] Low-end acceleration

The CSR has excellent low-end acceleration because of its high power to weight ratio of 410 bhp per ton (260 model). It can accelerate from a stop to 60 mph in 3.1 seconds (estimated)^[1], though during trials, Car and Driver magazine could only achieve 3.6 seconds.^[8] This discrepancy is due to the close gear ratios of the transmission and the rev limiter. The CSR cannot reach 60 mph in first gear, and required the extra 0.5 seconds to shift. Car and Driver explains:

It’s also wickedly quick, blowing past 60 mph in 3.6 seconds. We’ve gone a couple 10ths quicker to 60 in a Z06. The Caterham had an improperly set rev limiter that cut fuel at 7700 rpm, 300 rpm short of the redline and 2 mph short of 60 mph. At 7700 rpm, the Caterham is going 58 mph, so we had to do a time-consuming shift before hitting 60 mph. The Z06 clears 60 in first gear. With the correct fuel cutoff, at 8000 rpm, so could the Caterham, and it would likely hit 60 mph in the low threes.[8]

For comparison, the Porsche 997 Turbo, which weighs over twice as much as the CSR, only has a PtW ratio of 269 bhp per ton, but has a 0-60 mph time of 3.4 seconds.^[3]

[edit] High-speed problems

The CSR, as with all Caterhams, has worse high-end performance with respect to both acceleration and handling because of the poor aerodynamics. Caterhams suffer from a high drag coefficient of 0.7, but also from lift.^[9] Though there have been improvements in aerodynamics, the CSR still has 50 pounds of lift at 100 mph.^[1][10] These factors hinder both high-end acceleration, top speed, and handling. With such strong wind resistance, it requires much more power to overcome that force and increase top speed. Lift reduces contact force on the tires, causing the car to feel "loose" and not handle as well. For comparison, the Ferrari Enzo has a low drag coefficient of 0.32 and actually creates 1709 lbs of downforce at 186 mph. ^[11][12]

[edit] Cosworth engine

[edit] 260 model

The Cosworth-tuned engine is heavily modified from the stock 2.3 liter Duratec. The cylinder heads, blocks, crankshaft, connecting rods and pistons are upgraded by Cosworth.^[1] Cosworth also integrates an advanced dry-sump with an extra internal scavenge pump to distribute the oil. While a dry-sump system requires more oil, under hard cornering, a dry-sump will keep the engine lubricated unlike a wet-sump system. Cosworth also radicalizes the cam shafts and upgrades the exhaust system. this may cause to engine to run a little more "rough," but it drastically increases performance. The inlet system is also replaced with an advanced, custom roller-barrel system. This increases airflow at full throttle compared to a butterfly inlet, boosting performance. The engine also has a custom chip designed by cosworth for a further increase in performance.^[1]

[edit] 200 model

The 200 bhp model is not as heavily modified. The connecting rods and pistons are not upgraded significantly, though it does have the dry-sump system. The cam shafts are slightly radicalized, and the exhaust system is upgraded. The inlet system is enlarged, but not replaced with the roller-barrel system. The computer chip is upgraded, but not to the extent the 260 model is. Generally speaking, the 200 model is upgraded, albeit not as heavily.^[1]

[edit] Other features

The CSR, has a variety of other features which enhance its performance. There are no power brakes or power steering, makes the CSR extremely responsive and extremely agile. The clutch also engages extremely high, allowing for quick shifts while racing. In addition, the flywheel is very light. This makes heel-and-toeing extremely quick and easy as the engine revs up very quickly with so little momentum.

[edit] Improvements

Improvements were made to the Super Seven design, all designed to increase the performance of the vehicle.

[edit] Chassis

The overall strength of the chassis is improved with the addition of new tubular steel to the frame. The weight of the car increases, but the torsional stiffness is improved by somewhere between 25%^[1] and 100%^[13]. The added reinforcement was necessary in order for the CSR to support the heavy 2.3 liter Duratec engine. The CSR is also wider than previous models, which increases handling ability.

[edit] Suspension

Both rear and front suspension were completely redesigned for the CSR. The front suspension has double wishbone, fully adjustable, inboard springs and dampers, improving aerodynamics. The rear suspension is also upgraded to a double wishbone, fully independent system, replacing the De Dion tube design.

[edit] Aerodynamics

All Caterhams have very poor aerodynamics, mainly because of the blunt windscreen and the open-wheel design. At very high speeds, lift becomes a problem. To combat this, the CSR has several features that reduce lift by 50%.^[1] The front cycle wings are fitted closer to the tires to reduce turbulence and are angled to direct air upwards. Also, the new front suspension scheme reduces turbulence and drag formerly caused by the spring and damper units. The biggest enhancement is the vent added on top of the nose cone. A plastic panel behind the radiator directs air straight out through the vent. On previous models, the air from the radiator would cause turbulence, knocking against the engine and other parts on the underside.

[edit] Criticism

[edit] Ease of driving

A primary criticism is the ease of driving. The CSR provides few comforts found in a standard automobile today. There is no hard roof, only a rudimentary canvas hood that must be attached manually as well as removable canvas doors, called "sidescreens". It does not have a stereo or any kind of audio system. It also lacks any kind of climate control system; as an option, a heater can be added, but no air conditioning unit is available. The interior also does not have sufficient insulation, which is an option to begin with, to prevent heat from the engine compartment moving into the pedal box. The pedal box can get very hot to the point of possibly burning exposed flesh if it touches the metal. The seats are only adjustable forward and backward and is unadjustable in any other direction which can cause discomfort for some drivers or passengers. The pedal box is so narrow there is no room for a dead pedal, causing for uncomfortable positioning of the left foot. Also the CSR can only carry one passenger and has an incredibly small trunk. In essence, the CSR is a car designed to be a just barely street-legal race car, meaning it is not meant for everyday driving.^[13]

[edit] Safety

Under controlled, racing conditions, the provided safety features are sufficient because of limited, one-way traffic , but driving on the street poses many safety risks. Because of its very low ride height, the Caterham CSR is largely hidden from Semi-Trucks and SUVs. Its safety features are limited to four-point seatbelts in both seats and a roll-over bar and honeycomb reinforced side panels (floor panels available as option).^[1] The CSR only has a tubular steel frame. The skin of the car is simple thin aluminum sheets, which add no protection from impacts. This means occupants are largely unprotected from a side collision. The CSR also has no airbags. Because of the minimalistic, "add lightness" philosophy, Caterhams in general lack modern safety features.

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[edit] Security

There is no way to lock the CSR. The canvas hood simply snaps on. The same is true of the trunk cover. The only lock on the car is the ignition, which is a rudimentary key. To add to the problem, the wires of the ignition are easily visible and exposed underneath the dashboard, which makes the CSR more susceptible to hotwiring and theft.

[edit] Review

Overall, the reviews of the CSR have been positive. All US magazines tested the 260 model. The main criticism relates to the ease of driving, but the cost is also an issue.^[13]

• Automobile Magazine's Preston Lerner was impressed by the performance of the CSR:

"The Caterham is the purest and most honest street car I've ever driven. Period. No power steering. No power brakes. No drive-by-wire. Just a direct connection between you and the contact patch. The responses to steering, throttle, brake, and gearshift inputs are so nearly instantaneous that they verge on the telepathic. And I can see exactly what's happening, at least at the front end of the car, as the wheels turn and judder."^[13]

• But complains about its uncomfortable ride:

"The CSR isn't built for long-distance highway travel. Although the ride quality falls short of punishing, I'd strongly discourage using the car for emergency surgery. The otherwise comfy seats move fore and aft, but the rake is fixed, which can be-and was for me-a real pain. Speaking of driver discomforts, there's no dead pedal for your left foot, and your right thigh gets a good grilling from the aluminum transmission tunnel. The snap-shut side curtains can't be raised or lowered like conventional windows, so you're either freezing or sweltering."^[13]

• Autocar complains about the price, but enjoys the CSR overall:

"Which brings us on to the CSR 260’s biggest problem: the price. A basic CSR 260 costs £37,000 if Caterham builds it, £34,500 if you do it yourself. Then there’s paint at £795, or £1100 for metallic. And those carbon seats? Lovely, but they cost £1200. Aerofoil front suspension arms are very cool, but should be for £500. And that limited-slip differential is £750. Caterham is asking a lot of money for this car.

The CSR 260 is an intoxicating, extreme car, with racecar-like performance, fabulous grip levels and exceptional steering and handling. Few road cars will keep up with it in a straight line, fewer still down a twisting road or on a race track, and it has an excellent engine. But it isn’t perfect — the car’s packaging is showing its age and Caterham is demanding a serious amount of cash for a car that is so compromised — and so spartan."^[14]

• Edmunds.com enjoyed the CSR overall:

"The CSR has got to be the performance bargain of the car world, despite any flaws when it comes to civility. As previously mentioned, the roof and flimsy side doors are useless. Luggage space is nearly nonexistent, and you better be OK with the fact that anything short of a Razor scooter will tower over you on the road. But what is all this harping about creature comforts? This is a Caterham Seven after all, the fastest to ever leave the factory and maybe the quickest accelerating car on the planet. That counts more than cupholders any day."^[15]

[edit] Purchasing and licensing

[edit] In the UK

The CSR is a legal production vehicle under the Single Vehicle Approval scheme pending a vehicle inspection. The CSR may be purchased from Caterham directly as they are manufactured in the UK. The 200 bhp model starts at £31,000 and the 260 bhp model starts at £37,000 if built by the factory or £34,500 if bought as kit.^[1]

[edit] In the United States

The CSR was released in the United States in the summer of 2006 in very limited quantities. As a production vehicle, the CSR is illegal because of lack of safety features and failure to meet emissions standards. To circumvent this, the CSR is sold as a kit car. US law states that the engine and transmission must be purchases separately from the chassis. Chassis may be purchased from several different dealers located around the country; engines and transmissions may be purchased from Caterham USA.

Customers can choose to have the US dealer build their CSR for an extra fee, or opt to build their own. While many previous models of Caterhams are sold as kit cars to customers in the US, the complexity of the CSR makes this much more difficult, and is discouraged by dealers.

The US version is a standard left-hand drive and is exactly the same as the UK model. The base price of the chassis from Rock Mountain Sports Cars inc. is $44,000.^[16] This does not include the engine or transmission. The 260 bhp model engine and 6-speed transmission are estimated to cost an additional $23,000 for an estimated total cost of $67,000.^[13]

Licensing depends on individual state, county, and city regulations.

[edit] Facts and figures

[edit] Engine specifications

2.3-liter Ford Duratec tuned by Cosworth inline four

• Displacement: 2261 cc
• Bore and Stroke: 87.5 mm X 94 mm (undersquare)
• Valves: 16 valves, dual overhead camshafts
• Compression Ratio: 12:1^[17]

• Cooling: Water Cooled
• Oil Distribution: dry-sump with scavenge pump
• 260 Model
  • Maximum Power: 260 bhp at 7500 RPM
  • Maximum Torque: 200 lb ft at 6200 RPM
  • Power to Weight Ratio: 0.205 bhp per pound, or 410 bhp per ton
  • Throttle Body: Upgraded Roller-Barrel system
• 200 Model
  • Maximum Power: 200 bhp at 7000 RPM
  • Maximum Torque: 165 lb ft at 5750 RPM
  • Power to Weight Ratio: 0.158 bhp per pound, or 315 bhp per ton
  • Throttle Body: Widened butterfly system

[edit] Transmission specifications

Gear	Ratio (260 Model)	Ratio (200 Model)
1	2.69:1	3.36:1
2	2.01:1	1.81:1
3	1.59:1	1.26:1
4	1.32:1	1.00:1
5	1.13:1	0.82:1
6	1.00:1
Final drive	3.38:1	3.92:1

^[18]

[edit] Performance specifications

• Lateral Acceleration: 1.05 G's on skidpad
• 70-0 (Brake Test): 140 feet
• 0-60 mph
  • 260 model: 3.1 seconds (estimated) reported by manufacturer,^[1] reported as 3.6 seconds by Car and Driver^[8] See above for explanation of discrepancy.
  • 200 model: 3.7 seconds (estimated)
• 0-100 mph: 8.9 seconds (260 model)
• 0-120 mph:15 seconds (260 model)
• Quarter Mile: 12.1 seconds at 113 mph (260 model)
• Top Speed: 155 mph (260 model), 140 mph (200 model)

[edit] Vehicle specifications

• Size and Dimensions
  • Curb Weight: 575 kg (1268 lbs)
  • Wheelbase: 2315 mm
  • Length: 3300 mm
  • Width 1685 mm
  • Height 1015 mm (hood down), 1140 mm (hood up)
  • Ground Clearance: 100 mm
• Turning Radius: 11 m
• Steering: Rack and pinion, 2.2 turns lock to lock
• Brakes: 254 mm (10") discs, front vented, 4 piston front calipers

• Front Track: 1505 mm
• Rear Track: 1465 mm

• Seating Capacity: 2
• Tires: Avon CR500's, 195/45 R15 front, 245/40 R15 rear
• Lift: 50 lbs at 100 mph
• Weight Distribution (Front-Rear): 49%-51%

[edit] See also

• Caterham Cars
• Lotus Seven

[edit] References

[edit] External links

• Official Caterham Website
• Rock Mountain Sports Cars -A US distributor of Caterhams