Group 5 was an FIA motor racing classification which was applied to four distinct categories during the years 1966 to 1982. Initially Group 5 regulations defined a Special Touring Car category and from 1970 to 1971 the classification was applied to limited production Sports Cars restricted to 5 litre engine capacity. The Group 5 Sports Car category was redefined in 1972 to exclude the minimum production requirement and limit engine capacity to 3 litres. From 1976 to 1982 Group 5 was for Special Production Cars, a liberal silhouette formula based on homologated production vehicles.
35-601: The Lola T380 is a 3-litre Group 5 sports prototype , designed, developed and built by British manufacturer and constructor Lola , for sports car racing , in 1975. Two were made. One was for Alain de Cadenet ; the second was for International Race Services, an Italian team (HU2). Group 5 (racing) In 1966 the FIA introduced a number of new racing categories including one for highly modified touring cars, officially known as Group 5 Special Touring Cars. The regulations permitted vehicle modifications beyond those allowed in
70-517: A 3-litre engine capacity and were to be the main competitors in events counting towards the FIA's newly renamed World Championship for Makes from 1972 to 1975. Unlike the old Group 5, there was no minimum production requirement. For the 1976 season the FIA introduced a new Group 5 "Special Production Car" category, allowing extensive modifications to production based vehicles which were homologated in FIA Groups 1 through 4. These cars would contest
105-518: A coarse, open grain . The density of dry balsa wood ranges from 40 to 475 kg/m , with a typical density around 160 kg/m . Balsa is the softest wood ever measured using the Janka hardness test (22 to 167 lbf ). The wood of the living tree has large cells that are filled with water. This gives the wood a spongy texture. It also makes the wood of the living tree not much lighter than water and barely able to float . For commercial production,
140-536: A gear lever knob made of Balsa wood. When Porsche was first visited by the CSI inspectors only three cars were completed, while 18 were being assembled and seven additional sets of parts were present. Porsche argued that if they assembled the cars they would then have to take them apart again to prepare the cars for racing. The inspectors refused the homologation and asked to see 25 assembled and working cars. On April 20 Ferdinand Piëch displayed 25 917s parked in front of
175-559: A whole new car for the Sport category with one underlying goal: to win its first overall victory in the 24 Hours of Le Mans . In only ten months the Porsche 917 was developed, based upon the Porsche 908 , with remarkable technology: Porsche's first 12-cylinder engine, and many components made of titanium, magnesium and exotic alloys that had been developed for lightweight hillclimb racers. Other ways of weight reduction were rather simple, like
210-404: Is a pioneer plant , which establishes itself in clearings in forests, either man-made or where trees have fallen, or in abandoned agricultural fields. It grows extremely rapidly, up to 27 metres (89 ft) in 10–15 years. The speed of growth accounts for the lightness of the wood, which has a lower density than cork . Trees generally do not live beyond 30 to 40 years. Flowers are produced from
245-408: Is achieved through a kiln-drying process that leaves the wood's cells hollow and empty. Balsa wood is popular for light, stiff structures in model bridge tests, model buildings, and construction of model aircraft. It is also used in the manufacturing of wooden crankbaits for fishing, makeshift pens for calligraphy, composites, surfboards, boats, "breakaway" props for theatre and television, and even in
280-411: Is also used in laminates together with glass-reinforced plastic ( fiberglass ) for making high-quality balsa surfboards and for the decks and topsides of many types of boats , especially pleasure craft less than 30 m in length. On a boat, the balsa core is usually end-grain balsa, which is much more resistant to compression than if the soft balsa wood were laid lengthwise. More than 90% of
315-542: Is also valued as a component of full-sized light wooden aeroplanes , most notably the World War II de Havilland Mosquito . Balsa is used to make wooden crankbaits for fishing, especially Rapala lures. Sticks of dried balsa are useful as makeshift pens for calligraphy when commercial metal nibs of the desired width are not available. Balsa wood is often selected as a core material in composites . Because O. pyramidale grows quickly and tolerates poor soils it
350-433: Is low in density but high in specific strength (strength per weight), balsa is a very popular material for light, stiff structures in model bridge tests , model buildings, and construction of model aircraft ; all grades are usable for airworthy control line and radio-controlled aircraft varieties of the aeromodeling sports, with the lightest "contest grades" especially valuable for free-flight model aircraft . However, it
385-435: Is lower in cost per performance compared to polymer foams like EPS while having better tensile strength than typical foams. For example, the blades of wind turbines are commonly constructed of many balsa plywood cores and internal spars covered with resin infused cloth on both sides. In table tennis rackets, a balsa layer is typically sandwiched between two pieces of thin plywood made from other species of wood. Balsa wood
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#1732801888787420-399: Is the softest commercial hardwood and is widely used because of its light weight. Balsa trees grow extremely fast, often up to 27 metres in 10–15 years, and do not usually live beyond 30 to 40 years. They are often cultivated in dense patches, with Ecuador supplying 95% or more of the commercial balsa. The wood from these trees is highly valuable due to its high strength-to-weight ratio, which
455-662: The Chevrolet Corvette had floor pans composed of balsa sandwiched between sheets of carbon-fiber-reinforced plastic . Norwegian scientist and adventurer Thor Heyerdahl , convinced that early contact between the peoples of South America and Polynesia was possible, built the raft Kon Tiki from balsa logs, and upon it his crew and he sailed the Pacific Ocean from Peru to the Polynesian Tuamotu Archipelago in 1947. However,
490-469: The FIA ) announced that the new International Championship for Makes would be run for Group 6 Sports-Prototypes limited to 3 litre capacity for the four years from 1968 through 1971. Well-aware that few manufacturers were ready to immediately take up the challenge, the CSI also allowed the participation of 5 litre Group 4 Sports Cars manufactured in quantities of at least 50 units. This targeted existing cars like
525-537: The Group B regulation, but continued to compete in JSPC , IMSA GTX category and other national sports car racing championships for a few more years. Balsa Bombax pyramidale Cav. ex Lam. Ochroma bicolor Rowlee Ochroma concolor Rowlee Ochroma lagopus Sw. Ochroma obtusum Rowlee Ochroma pyramidale , commonly known as the balsa tree , is a large, fast-growing tree native to
560-473: The Kon Tiki logs were not seasoned and owed much of their (rather slight) buoyancy to the fact that their sap was of lower density than sea water. This serendipitously may have saved the expedition, because it prevented the seawater from waterlogging the wood and sinking the raft. Balsa wood is also a popular wood type used in the arts of whittling , and surfing . In the making of picture frames, balsa
595-431: The kinkajou and the olingo , may be the primary pollinators. It is evergreen or dry-season deciduous , with large 30 to 40 centimetres (12 to 16 in), weakly palmately lobed leaves. Being a deciduous angiosperm , balsa is classified as a hardwood despite the wood itself being very soft; it is the softest commercial hardwood. Ecuador supplies 70% or more of commercial balsa. In recent years, about 60% of
630-497: The 3.5 atmo engine formula, reminiscent of events nineteen years previous. In an effort to reduce the speeds generated at Le Mans and other fast circuits of the day by the unlimited capacity Group 6 Prototypes such as the 7 litre Fords, and to entice manufacturers of 3 litre Formula One engines into endurance racing, the Commission Sportive Internationale (then the independent competition arm of
665-510: The Americas. It is the sole member of the genus Ochroma . The tree is famous for its wide usage in woodworking , due to its softness and its high strength compared to its low density. The name balsa is the Spanish word for "raft." A deciduous angiosperm , Ochroma pyramidale can grow up to 30 m tall, and is classified as a hardwood despite the wood itself being very soft; it
700-462: The Porsche factory to the CSI inspectors. Piëch even offered the opportunity to drive one of the cars, which was declined. During June 1969, Enzo Ferrari sold half of his stock to FIAT , and used some of that money to do what Porsche did 6 months earlier with the 917, to build 25 cars powered by a 5-litre V12 in order to compete against them. With the financial help of Fiat, that risky investment
735-675: The World Championship for Makes series from 1976 through to 1980 and then the World Endurance Championship in 1981 and 1982. The Deutsche Rennsport Meisterschaft also used these regulations from 1977 until 1981. The only non-circuit events that used Group 5 cars were in the Giro d'Italia automobilistico rally. The rules restricted the width of the car, therefore cars were built with standard body widths but wide mudguard extensions. The regulation required only
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#1732801888787770-542: The aging Ford GT40 and the newer Lola T70 coupe. In April 1968, the CSI announced that, as there were still too few entries in the 3 litres Group 6 Prototype category, the minimal production figure to compete in the Group 4 Sport category of the International Championship of Makes would be reduced from 50 to 25 starting in 1969 through to the planned end of the rules in 1971. This was mainly to allow
805-545: The balsa has been plantation -grown in densely packed patches of around 1000 trees per hectare (compared to about two to three per hectare in nature). The trees are harvested after six to ten years of growth in Ecuador. The remaining volume of balsa is harvested from plantations in Papua New Guinea; the climate is different, therefore harvesting occurs at 4-5 years of age. Balsa lumber is very soft and light, with
840-467: The bonnet, roof, doors and rail panel were left unmodified. The rules however did not mention headlight heights, therefore when Porsche originally were to enter the 935 with the production headlight, they read the rules and discovered the loophole, therefore they raced the 935 with the hallmark flat nose. The category was also mostly associated with the wide boxy wheel arches and extravagant body style. The category would be banished after 1982 in favour of
875-715: The concurrent Group 1 and Group 2 Touring Car categories. Group 5 regulations were adopted for the British Saloon Car Championship from 1966 and for the European Touring Car Championship from 1968. The Special Touring Cars category was discontinued after the 1969 season. For the 1970 season, the FIA applied the Group 5 classification to the Sports Car class which had previously been known as Group 4 Sports Cars . The minimum production requirement remained at 25 and
910-454: The end of that year. Surprisingly, Ferrari decided to give up any official effort with the 512 in order to prepare for the new 1972 season regulations. But many 512s were still raced by private teams, most of them converted to M specification. As a result of the rule change, sports car racing popularity suffered and did not recover until the following decade, with the advent of Group C which incidentally were forced out of competition in favour of
945-426: The engine capacity maximum at 5 litres as had applied in the superseded Group 4. Group 5 Sports Cars contested the FIA's International Championship for Makes in 1970 & 1971, alongside the 3 litre Group 6 Prototype Sports Cars . During 1970 the FIA decided to replace the existing Group 5 Sports Car category when the rules expired at the end of the 1971 season, so the big 917s and 512s would have to be retired at
980-570: The floor pans of the Chevrolet Corvette . Balsa wood played a historical role in Thor Heyerdahl's Kon-Tiki expedition where it was used to build the raft. Balsa wood is also popular in arts such as whittling, and in the making of baroque-style picture frames due to its ease of shaping. A member of the mallow family, Ochroma pyramidale is native from southern Mexico to southern Brazil, but can now be found in many other countries (Papua New Guinea, Indonesia, Thailand, Solomon Islands). It
1015-693: The homologation in Group 4 of cars such as the Ferrari 250 LM and the Lola T70 which had not been manufactured in sufficient quantities to qualify (unless, in the case of the Lola T70, the open Can-Am cars were counted as well). Starting in July 1968, Porsche made a surprising and very expensive effort to take advantage of this rule. As they were rebuilding race cars with new chassis every race or two anyway, they decided to conceive, design and build 25 versions of
1050-404: The same support from the factory. They were considered as field fillers, never as candidate for a win. At Porsche, however, JWA Gulf, KG Salzburg who were then replaced by Martini Racing for the following season, received all direct factory support and the privateers like AAW Shell Racing and David Piper Racing received a much better support than Ferrari's clients. The 917 instability problem
1085-457: The third year onwards, typically at the end of the rainy season when few other trees are in flower. The large flowers open in the late afternoon and remain open overnight. Each may contain a pool of nectar up to 2.5 centimetres (0.98 in) deep. Daytime pollinators include capuchin monkeys . However, most pollination occurs at night. The main pollinators were once thought to be bats, but recent evidence suggests that two nocturnal arboreal mammals,
Lola T380 - Misplaced Pages Continue
1120-461: The wood is kiln-dried for about two weeks, leaving the cells hollow and empty. The large volume-to-surface ratio of the resulting thin-walled, empty cells gives the dried wood a large strength-to-weight ratio because the cells are mostly air. Unlike naturally rotted wood, which soon disintegrates in the rainforests where balsa trees grow, the cell walls of kiln- seasoned balsa wood retain their strong structure of cellulose and lignin . Because it
1155-468: The world's Balsa wood volume is prepared into end grain panels for the composites industry, mostly used as structural cores in the wind turbine blades. Where strength, rigidity, durable and environmentally sustainable materials are sought after. Balsa is also used in the manufacture of "breakaway" wooden props such as tables and chairs that are designed to be broken as part of theatre, movie, and television productions. The fifth and sixth generations of
1190-405: Was made, and surplus cars were intended to be sold to racing customers to compete for the 1970 season. Within 9 months Ferrari manufactured 25 512S cars. Ferrari entries only consisted of the factory cars, tuned by SpA SEFAC and there were the private cars of Scuderia Filipinetti, N.A.R.T., Écurie Francorchamps, Scuderia Picchio Rosso, Gelo Racing Team and Escuderia Montjuich which not receive
1225-468: Was resolved with a revised rear hatch, which was called 917K (Kurzheck). There was a long tail version known as the 917LH (Langheck). Towards the end of the 1970 season, Ferrari entered some races with a new version of the 512, the 512M which had a revised bodywork For 1972, the FIA applied the Group 5 classification to what had previously been known as the Group 6 Prototype Sports Cars category. These cars, now officially Group 5 Sports Cars, were limited to
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