Lotus 25
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| Constructor: |
 lotus
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| Designer: | Colin Chapman | ||||||||
| Predecessor: | Lotus 24 | ||||||||
| Successor: | Lotus 33 | ||||||||
| Technical specifications | |||||||||
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| Chassis: | Aluminum / steel monocoque | ||||||||
| Length: | 3556 mm | ||||||||
| Width: | 1549 mm | ||||||||
| Height: | 787 mm | ||||||||
| Wheelbase: | 2311 mm | ||||||||
| Weight: | 450 kg | ||||||||
| Tires: | Dunlop L Racing | ||||||||
| statistics | |||||||||
| First start: | 1962 Dutch Grand Prix | ||||||||
| Last start: | 1965 Mexican Grand Prix | ||||||||
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| World Cup points: | 157 | ||||||||
| Podiums: | 18th | ||||||||
| Leadership laps: | 1071 over 5565.899 km | ||||||||
The Lotus 25 was a Formula 1 racing car made by the British manufacturer Lotus . It was the first Formula 1 car with a monocoque and is considered a milestone in racing history that revolutionized Formula 1. The 25 was initially reserved for the Lotus factory team. In 1963 , works driver Jim Clark won the drivers 'championship and Lotus won the constructors' world championship with him.
construction
A special feature of the Lotus 25 was its monocoque construction. Other manufacturers had repeatedly implemented comparable concepts since 1950, including Jaguar with the D-Type from 1954 and Marcos with the GT from 1959. However, such a design did not exist in Formula 1 until the early 1960s. Lotus founder Colin Chapman adopted the concept of the monocoque from Marcos; Observers see a clear constructive similarity between the Marcos and the Lotus monocoque.
Like the Marcos GT, the Lotus 25 had a shell-type chassis that, unlike the Marcos, was not made of plywood, but of aluminum. The chassis was very light with a dead weight of 30 kg. The body was made of plastic. Despite its low weight, the monocoque construction resulted in a very high strength of the chassis, which on the one hand increased safety and on the other hand improved handling in bends. The engine was set in a tubular steel frame. This led to the driver sitting in an almost lying position, which earned the car the nickname “bathtub” and which Jim Clark initially met with little approval. The chassis was similar to that of the Lotus 24. On the front axle, the upper wishbones were designed as rocker arms, which actuated the internal spring and shock absorber unit, and triangular wishbones were installed below. The rear axle consisted of a triangular wishbone and double trailing arms with external springs and dampers. There was also a rack and pinion steering and disc brakes at the front and rear. Wheel size: 15 × 5.5 inches at the front, 15 × 8 inches at the rear.
The 25 has been used with different engine-gearbox combinations over the years. The Lotus factory team used Coventry-Climax -FWMV engines (90 °) with eight cylinders from 1962 to 1965 . The displacement was 1497 cm³. From this the engine developed 190 hp at 10,000 rpm. For power transmission, Lotus used a longitudinal five-speed transmission from ZF (type 5DS10), which was positioned on the rear axle, and a two-disc sintered metal clutch . The top speed of this version was around 250 km / h.
In addition to the works team, the private racing team Reg Parnell Racing also used a Lotus 25 at times. The team drove with an eight-cylinder BRM engine (type P56) and a five-speed gearbox from Hewland .
Race results in Formula 1
Lotus initially reserved the 25 for its own factory team. It was not until 1964 that Reg Parnell Racing, a private team, came into possession of two Lotus 25. Parnell used the car almost continuously until spring 1967. The Lotus 25 appeared only sporadically with other private teams.
Works team
1962
The Lotus 25 made its debut at the first world championship run in 1962 in the Netherlands . At first, only Jim Clark drove the new car, while his teammate Trevor Taylor drove an older Lotus 24 . For the French Grand Prix , a second 25 was ready: Clark received the new chassis (R2), while Taylor took over the previously driven by Clark car (R1).
When the Lotus 25 made its debut at Zandvoort , after a long duel with Graham Hill , Clark dropped out in second place due to a clutch defect. The race for the Belgian Grand Prix was won by Clark ahead of Graham Hill and Phil Hill . The second win on a Lotus 25 was won by Clark at the British Grand Prix . His third win followed at the US Grand Prix at Watkins Glen . At the end of the season, Clark was runner-up in the constructors' championship with 30 points behind Graham Hill and Lotus was also second behind BRM .
1963
In 1963 , the Clark / Lotus combination won seven of the ten world championship races and thus both the drivers 'and the constructors' world championships.
1964
For the Formula 1 season in 1964 , the Lotus 25 received a modified front suspension and 13-inch wheels. In the summer of the same year, the model was replaced by the successor Lotus 33 . By then, Clark had won two of his three victories that year on a Lotus 25.
Reg Parnell Racing
The British private team Reg Parnell Racing took over two Lotus 25s in early 1964 and used them in Formula 1 world championship races until 1967 .
In 1964, Chris Amon and Mike Hailwood were regular drivers for the team, and Hailwood's Peter Revson took the place of one race . Amon finished fifth in the Dutch Grand Prix , Hailwood sixth in the opening race in Monaco . Apart from that, there were only five other finishings, of which Hailwood's eighth place in Austria was the best. In the remaining races, the team suffered from the unreliability of the BRM engine, which led to technical failures five times.
In 1965 , Reg Parnell Racing was the only team still racing a Lotus 25. The factory team had already switched to the Lotus 33, which in turn was initially not available to the customer teams. This year, two former Lotus works drivers, Richard Attwood and Innes Ireland, were the regular drivers for Reg Parnell. In addition to them, Chris Amon contested two and Mike Hailwood and Tony Maggs each one. There were ten finishings for the team this year, but not in the points.
1966 was the first year of the so-called three-liter formula: for the first time naturally aspirated engines with a displacement of up to 3.0 liters were permitted. None of the new engines were available to Parnell, so the team kept the Lotus 25 and BRM engine combination throughout the season. However, in the course of the year BRM increased the size of the small eight-cylinder to 2.0 liters. Parnell received this engine in the spring of 1966. That season only Mike Spence drove for Reg Parnell. He was also a former Lotus works driver. He retired seven times in nine races, and twice - in the Netherlands and Italy - he finished fifth.
For the 1967 season , Parnell acquired two previous year's chassis from BRM. The now five-year-old Lotus 25 was only used twice this year: In the opening race in South Africa , Piers Courage took it to the start, but did not finish. In the Netherlands , Chris Irwin drove the car and finished seventh. That was the last Formula 1 race in a Lotus 25.
Rob Walker Racing
The British private Rob Walker Racing Team fielded a Lotus 25 with a 1.5 liter Climax engine for Jo Bonnier at the South African Rand Grand Prix in December 1965 . Bonnier retired prematurely on the 19th lap due to a defective radiator.
Formula 2
The seventh and final chassis of the Lotus 25 (R7) was converted in 1967 according to the rules of Formula 2 . It received a 1.5 liter four-cylinder engine from Cosworth . Mike Spence drove the car for Reg Parnell Racing in a number of races.
literature
- David Hodges: A – Z of Grand Prix Cars. Crowood, Marlborough 2001, ISBN 1-86126-339-2 .
- David Hodges: Racing cars from A – Z after 1945. Motorbuch-Verlag, Stuttgart 1994, ISBN 3-613-01477-7 .
- Mike Lawrence: Grand Prix Cars, 1945–65. Motor Racing Publications, Croydon 1998, ISBN 1-899-87039-3 .
- Peter Voncken: Start of the lotus blossom. In: Motorsport aktuell . Issue 38, September 3, 2013, pp. 36–37.
Web links
Individual evidence
- ↑ a b c d Hodges: Racing cars from A – Z after 1945. 1994, p. 145.
- ↑ Adriano Cimarosti: The century of racing. Cars, tracks and pilots. Motorbuch-Verlag, Stuttgart 1997, ISBN 3-613-01848-9 , p. 181.
- ↑ a b c Lawrence: Grand Prix Cars, 1945–65. 1998, p. 193.
- ^ A b David Hodges: A – Z of Grand Prix Cars. 2001, p. 133.
- ^ Statistics of the VIII Rand Grand Prix on the website www.formula2.net (accessed on September 4, 2013).
- ↑ Lotus 25 R7 on the website www.oldracingcars.com (accessed on September 4, 2013).
