The 1977 24 Hours of Le Mans was the 45th Grand Prix of Endurance, and took place on 11 and 12 June 1977. The second year of the FIA Group 5 and Group 6 regulations, it produced an exciting race right up to the end. Porsche had withdrawn from the Group 6 Championship, citing a lack of broad competition. Renault, before their move into Formula 1, decided to put its main racing focus for the year onto Le Mans. The two works teams were the pre-race favourites.
From the start the Alpine-Renaults took charge. The works Porsches mounted a brief challenge but engine issues delayed them in the pits. When Pescarolo retired his 936 with engine problems, his co-driver Jacky Ickx was transferred to the sister car of Barth/Haywood, languishing in 41st place and 15 laps behind the leaders. Ickx was given free rein to drive as hard as he dared and in an epic drive through the night, his average pace was just two seconds below qualifying pace. During the night, the French challenge started to come apart – Tambay's car, running fourth, stopped at 3am with a dead engine. An hour later, the second car lost half an hour getting a gearbox rebuild. Then at 9am, after leading for 17 hours, the Jabouille and Bell car retired with a burnt-out piston.
Suddenly, Porsche found itself in the lead. Ickx finished his marathon effort after a total of eleven hours behind the wheel. Barth and Haywood kept up his pace and when the last Renault retired just another midday with another burnt piston, they could ease off with a huge 19-lap lead over the Mirage of Schuppan/Jarier. However, with only three-quarters of an hour to go, Barth pitted running on five cylinders. The mechanics treated the engine and waited, until with ten minutes to go he rolled back out onto the circuit to complete two final laps. Despite the delay, they still finished 11 laps ahead of the Mirage, the biggest winning margin of the decade. The French Porsche 935 of ASA-Cacchia was third, a further 16 laps behind, with the GTP Inaltéra of owner-driver Jean Rondeau, and Alain de Cadenet both barely ninety seconds behind.
Regulations This was the second year of the latest CSI regulations. The FIA still insisted on running dual Championships for Group 6 (World Championship for Sports Cars) and the World Championship for Makes for Groups 4 and 5.Spurring 2011, p.237 Group 6 allowed either a standard production engine up to 5-litre capacity or racing engines up to 3-litres (or 2.1 litres if turbo-charged). Group 5 encouraged manufacturers to adapt and modify their Touring (Group 2) and Grand Touring (Group 4) cars, including an aerodynamic silhouette body-shell. Once again, like the year before, the Automobile Club de l'Ouest (ACO) was put off by the small championship fields and decided to run both classes together in the race. And, once again, this put them at odds with the FIA who excluded them from their championships.Clarke 1997, p.54: Motor Sport Jul 1977
The Group 2 Touring Car class, never strongly supported, was dropped this year. However, some Class 2 cars were entered in the IMSA and Group 5 classes instead. Maintaining its ties with the IMSA organisation, they accepted entries under the American GTO regulations. The ACO also took entries from their own evolved rules of the CSI system: GTP, a closed-body development of Group 6, and GTX from Group 5.
After complaints by Renault the previous year of the fuel quality which had compromised their car's race, the Octane rating was raised to 100.6, the same as that used in Formula 1. Limitations of the distance between refuelling stops were finally removed, although cars had a fuel tank maximum of 160 litres.
After a year's abeyance, the fuel-economy trophy was restored: renamed as the Index of Energy Efficiency. A table of target fuel consumption was drawn up against average speed, and that reference figure was divided by the actual consumption. The final checks were made at the hour-22 fuel stops so that cars would not artificially benefit from slowing down at the end to conserve fuel.Spurring 2011, p.9
Entries The ACO received 88 applications, across the 7 classes with 62 arriving for qualifying on race week. The only manufacturer works teams were from Porsche and Renault, although there were entries from several small-scale racing specialists like Inaltéra, Mirage, Osella and WM. The rise of turbo-powered cars continued with them making up 23 of the 62 cars.
Class Large-engines >2.0L classes Medium-engines < 2.0L classes Turbo engines Group 6 S Sports 13 / 12 11 / 9 8 / 0 Group 5 SP Special Production8 / 8 - 5 Group 4 GTS Special GT11 / 10 - 7 GTP Le Mans GT Prototype 6 / 5 - 3 GTX Le Mans GT Experimental 1 / 1 - 0 IMSA GT 12 / 10 - 0 Total Entries51 / 46 11 / 9 23 Note: The first number is the number of arrivals, the second the number who started.
Group 6 and GTP The Martini-Porsche works team had chosen not to contest the FIA Championship citing the lack of competition. The 1977 evolution of the Porsche 936 had a more aerodynamic shell, as well as being narrower. The 2.1-litre flat-6 engine had twin KKK (Kühnle, Kopp & Kausch) turbos and with two exhausts now it could develop 540 bhp and get up to almost 350 kp/h (215 mph) when the turbo was wound up. Two cars were entered with the all-star pairing of triple-champions Jacky Ickx and Henri Pescarolo in one and Jürgen Barth paired with debutante Hurley Haywood (himself a triple Daytona 24-hours winner) in the other.Spurring 2011, p.240-1
Renault-Alpine had also chosen not to run in the Championship, to make a major effort for the Le Mans win before focusing on Formula 1. Extensive work was done on the A442: it was lengthened to improve handling and larger, 14" front wheels fitted to allow bigger brakes. Aerodynamic testing was done on unopened autoroutes and in four separate endurance runs at the modern Circuit Paul Ricard. The test-car covered over 11,000 km. Renault engineers found the failure of the single car last year had been the low-grade fuel used.Clarke 1997, p.44 Motor Jun18 1977Spurring 2011, p.242Kettlewell 1977, p.211 The company spent FF3 million (£400,000) and sixty pit-crew were on hand to support an all-out effort. The driver lineup featured some of France's leading single-seater drivers with Jacques Laffite / Patrick Depailler and Patrick Tambay / Jean-Pierre Jaussaud, while the third car had veterans Jean-Pierre Jabouille and Derek Bell. In addition, Hugues de Chaunac, manager of the Martini-Renault Formula 2 team was given the test-car as a client entry for his young drivers René Arnoux and Didier Pironi.
Mirage managers Harley Cluxton and John Horsman had contemplated running the Renaults. However, in the end they instead chose to upgrade the M8 with the 490 bhp Renault turbo engine, to replace the Cosworth DFV. Renault Sport's director Gérard Larrousse agreed, as long as each car ran a French driver. The chassis was modified with a new airbox to cool the turbo.Spurring 2011, p.246 Team regular Vern Schuppan was paired with Jean-Pierre Jarier and American Sam Posey teamed up with Michel Leclère. Jarier was a late substitute for Jean-Louis Lafosse who had not arrived with promised sponsorship money, which gave the lawyers work to argue in court.Clarke 1997, p.49-50 Autosport Jun16 1977
Alain de Cadenet, with his regular co-driver Chris Craft, returned with their latest modified version of the Lola T380, the LM77. The rear wing of the car patriotically celebrating the Queen's Silver Jubilee. Once again they did their habit of arriving, and preparing the car, at the last minute in the paddock.Clarke 1997, p.46 Motor Jun18 1977 Their car from the previous year was bought by Simon Phillips of the Dorset Racing Associates team and was co-entered with de Cadenet.Spurring 2011, p.252 French privateer, Xavier Lapeyre, again entered his Lola T286.Spurring 2011, p.226
Le Mans local Jean Rondeau's team had had an excellent debut the previous year winning the new GTP class. This year, three cars were entered – still bearing the name of their sponsor, French home-furnishings company Inaltéra. One stayed in the GTP class (driven by Rondeau himself, with Jean Ragnotti) while the other two were lightened by 95 kg and modified to run in the Group 6 class. French Formula 1 veteran Jean-Pierre Beltoise drove one with American Al Holbert and the other had the all-female pairing of Italian Lella Lombardi with Belgian Christine Beckers.Spurring 2011, p.248
Former Peugeot staff Gérard Welter and Michel Meunier were back with their WM P76 in GTP class. The Peugeot 2.7-litre V6 engine put out 250 bhp. They also completed a second P77 chassis, this time fitted with a KKK turbo that increased the power output to a far more competitive 380 bhp.Spurring 2011, p.255 Another all-French entry was Bernard Decure's modified Alpine A310, fitted with the V6 PRV engine.Spurring 2011, p.262 Another GTP entry saw the return to Le Mans of Aston Martin. Entered by Englishman Robin Hamilton, his DBS V8 had progressively been modified to meet Group 4 and Group 5 regulations. The 5.3-litre V8, with its extensive modifications, put out 510 bhp and got the car up to 300 kp/h (188 mph). Being the heaviest car in the field, the French fans nick-named it le petit camion ("little lorry") and the ACO allowed him to switch across to the GTP class. Hamilton was joined by his regular co-driver David Preece along with Mike Salmon, who had been one of the drivers of the last Aston Martin entry, back in 1964.Spurring 2011, p.265 French rally driver Robert Neyret ran his Lancia Stratos again in the GTP class, the 2.4-litre Ferrari V6 modified with a KKK-turbo. This year female driver Christine Dacremont was partnered with Marianne Hoepfner.Spurring 2011, p.262
Group 6 (2-litre) The under-2000 class was spiced up with new manufacturers entering what had been a Lola versus Chevron battle, and there was a good 11-strong field. The class encouraged mixing the chassis with a choice of engine. The French engine-builder, Société ROC, had three of the latest B36 Chevrons (the lightest cars in the race) while the British Chandler-Ibec team ran a Chevron-Ford. Their compatriots Dorset Racing had a Lola-Ford as did the Swiss GVEA team while French privateer Jean-Marie Lemerle had a Lola-ROC combination.
Having moved on from Formula Two, Osella had been the leading 2-litre marque in the World Championship, often running second to the 3-litre Alfa Romeos. One of the FA5 works cars was entered, with its 2-litre BMW engine. Enzo Osella replaced his usual driving line-up for the race with Alain Cudini, Raymond Touroul and Anna Cambiaghi.Spurring 2011, p.259 Peter Sauber's little Swiss outfit had built a small number of monocoques for hill-climbing. He was now looking at circuit racing with the C5, also powered by the BMW engine. Herbert Müller had won the 1976 Interserie trophy with it and now they looked to Le Mans. It would be driven by fellow Swiss Eugen Strähl and Peter Barnhard.Spurring 2011, p.258 The other entries were two from another small Swiss manufacturer, Cheetah. Charles Graemiger had a new BMW-powered G601 for privateer Daniel Brillat, while the older G501-Cosworth was prepared for Inaltéra owner André Chevalley.Spurring 2011, p.260
Group 5 and GTX
Porsche had been dominating the World Championship winning every round against sporadic competition from BMW, who were concentrating on the DRM championship in Germany. This year, Porsche built 13 of the 935 for general sale, at £35,000 each.Kettlewell 1977, p.215Spurring 2011, p.250-1 So the Group 5 entry list was the sole preserve of Porsche.