1973 ENDURANCE RACING

 The Ferrari vs Matra combat for the WCM

STARTING THE 1973 SEASON

I think that there can hardly be any discussion that the period 1964-1973 was an absolute unique decade in the history of autosport. From 1964 to 1967 there was the thrilling combat between Ford and Ferrari (with Ferrari winning the Manufacturer's Worlds in 1964 and 1965 and with Ford doing it in 1966 and 1967). Undoubtedly the legendary Ford-Ferrari combat contributed to the popularity of autosport among the non-initiated. End 1967 this splendid highlight in autosport history came to an end when the FIA banned the Ferrari 330 P4, Ford Mk IV, Ford MkIIB and Chaparral 2E from the race tracks.
1968 and 1969 were rather meagre years in endurance racing, not to compare with the passion having opposed the adepts of American race technology and the defenders of the European approach. It were the years of the Ford-Porsche combat for Le Mans, lost at two occasions by Porsche.
1970 was again a superb year with the combat among the Porsche 917 and the Ferrari 512S, won in a brilliant way by Porsche. It was the struggle between the 5-litre sports cars assembled at 25 identical copies at least. Unfortunately the FIA informed already early 1970 that 1971 should be the last year where 5-litre sports cars could be raced. That let Enzo Ferrari decide stopping to send works Ferraris to the rounds of the 1971 Manufacturer's Worlds. So Porsche had not the smallest problem to prolong its title in 1971.
Up from 1972 the situation in endurance racing was seriously simplified: the three main classes were now Group 5 with sport-prototypes (S) having an engine capacity under 3 litres; Group 4 with grand touring cars with unlimited engine capacity (GTS); and Group 2 with special touring cars with 4 seats (TS). Since 3-litre engines were used in F1 several manufacturers like Ferrari, Matra-Simca, Alfa Romeo, Mirage Gulf and Lola decided to equip their Group 5 cars with F1 motors. Since most works drivers were also active in F1 racing endurance racing became at once a F1 competition over 1,000-kms or 24 hours. Unfortunately the two best cars - the Ferrari 312PB and the Matra-Simca MS670, both equipped with a 12 cylinder engine - were never seen in a direct confrontation. Ferrari won 10 of the 11 rounds and was absent at Le Mans; Matra was absent at all other rounds than Le Mans.
Interesting too was the fact that such cars as Chevron B16, B19, B21, B23 and Lola T290 and T290 were raced since 1970 with under 2-lire motors directly derived from F2. Although those cars had their own European Sports Car Championship, they were also entered at endurance races for the World Championship of Makes (WCM).

The major enigma of 1972 was: how is it possible that the Ford-Cosworth V8, so successful in F1 racing, was systematically beaten by the new 12 cylinder engines? Already in 1972 John Wyer from Mirage Gulf and Carlo Chiti from Autodelta Alfa Romeo insisted to replace the 8 cylinder engines by a 12 cylinder version, having won all 11 rounds at the new World Championship for Makes. Only the successors of the late Joachim Bonnier - having had a fatal accident at the 1972 Le Mans 24 hours - continued with the Ford-Cosworth DFV engine.
1973 was the last year of a unique decade in autosport. Unfortunately the expectations of a thrilling combat between the 12 cylinder cars of Matra, Ferrari, Mirage and Alfa Romeo could not be redeemed. The Weslake V12, ordered by Mirage, was hardly more than a pure disaster, resulting in a long trial between John Wyer and the 76 year old Harry Weslake. Moreover there was a serious economic crisis in Italy, resulting in continuous strikes of the metalworkers, so that the Alfa Romeo 12 cylinder engine was could only be raced a first time at round #6, the Targa Florio. But also Ferrari suffered seriously from the strikes (also from the fact that the Agnelli Bros of Fiat had decide to restrict the racing budgets). Without considerable technological progress the invincible 312PB of the previous year was at once inferior to the new Matra-Simca MS670B. Moreover Ferrari lost his excellent race manager, Paul Schetty (having returned to the textile industry of his father), and had to replace him by the inexperienced Gaicomo Caliri. So, at more than one point, 1973 was a disappointing season. Three events, however, made that 1973 was an unforgettable year in the history of motorsport. (1) Being 50 years old the Le Mans 24 hours of 1973 were one of the most exciting of whole history. (2) It was the year of the last Targa Florio, with 700,000 people out along the track, an absolute record in the history of autosport. (3) Although the Matras were superior in speed and road holding (but not in reliability) to the Ferraris, Gérard Ducarouge and Jean-Luc Lagar-dère had to fight until the real last round to win the WCM.
Compared to the previous seasons the Sebring 12 hours and Brands Hatch 1,000-kms were no longer a round of the WCM. They were replaced by the Vallelugna 1,000-kms and the Dijon 1,000-kms. The Buenos Aires 1,000-kms, in previous years the curtain raiser of the WCM, were now scheduled as last round. However, this race was cancelled after the famous oil crisis at the end of the year. Prices of crude oil quadrupled and at once motorsport became something insane: wasting the black gold was no longer appreciated by the crowds. Never later endurance racing fully recovered from the oil crisis.  

¶1. SURVEY OF THE 1973 CARS

1.1. GROUP 5 S3000 CARS

             3.0 Ferrari 312PB-73
Despite the fact that Fiat decided to reduce the budget for endurance racing, there is no doubt that Ferrari wishes to defend his title of world champion in 1973. The social strikes, however, will perturb seriously the plans to develop the car. At the first round - the Daytona 24 hours - no 312PB will be present. For budget reasons 3 of the 9 312PBs are sold. The remaining cars are rebuilt with a longer wheelbase and a wider front track. The maximum rev limit has been increased to 11,600rpm (instead of 10,800rpm). At 1,000-km races power output will be up to 475bhp for 2,998cc. Weight of the car increases from 650 kgs to 690 kgs. Engine torque is improved by fitting a new exhaust system as on the F1 Ferraris. The Firestone tires from 1972 are replaced by Goodyear ones. An airbox has been mounted between the struts of the roll-over body and the rear wing is now integral with the body. On some cars the single airbox will be later replaced by twin air-scoops as on the right pictures.
Inboard mounted ventilated brakes are fitted on the cars so that the triangular wishbones of the previous year have been substituted by parallel rods. Ronnie Peterson, Clay Regazzoni and Mario Andretti are replaced as works drivers by Carlos Pace (member of the Surtees F1 team), Carlos Reutemann (coming from Brabham F1) and the hot-boiled Arturo Merzario (having already driven last year for Ferrari). Jacky Ickx, Brian Redman and Tim Schenken remain as works drivers.
The modified cars, with a much longer rear tail, are tested mid-February at the new Paul Ricard circuit. Racers complain that the handling of the 312PB-73 is highly unpredictable, with a tendency to switch rapidly from oversteer to understeer. During the whole season Ferrari engineers will try to solve that handling problem,  but there are no funds for major developing work. Funds are rather used for the development of the 1974 F1 car by Mauro Forghieri.

              3.0 Alfa Romeo 33TT12
In 1972 the 8 cylinder Alfa Romeo 33TT3 was beaten time after time by the Ferrari 312PB with its flat 12 cylinder engine. So Carlo Chiti insisted to race this year the new 12 cylinder 2,995cc motor, developing 475bhp at 11,500rpm. Other sources speak even of ...500 bhp. The unit is based on a Grand Prix motor of the 1950s which was never used. It has four valves per cylinder, gear driven twin camshafts on each bank and a compression ratio of 11:1. Externally the sides of the new body are completely flat. This radically new body type - which can only be found on the 2.0 Alpine-Renault A440 - will be in the coming years of great influence on other manufacturers of sports cars.
It's the intention that Autodelta will enter the car at all rounds of the WCM. As drivers Rolf Stommelen and Andrea de Adamich are maintained from the previous year. Clay Regazzoni - free from Ferrari - and Giancarlo Facetti of the Scuderia Brescia Corse are added to the team.
Unfortunately the new car suffers from all kinds of child diseases so that it will miss the four first rounds of the WCM, even the for Alfa Romeo so important Monza 1,000-kms. It will be seen for the first time at round #5: the Spa-Francorchamps 1,000-kms. Here, however, a flat tire at top speed during the qualifications will left the car beyond repair. So we have to wait the Targa Florio - the last in history counting for the WCM - to see two copies of the Alfa Romeo 33TT12 in action. But at the qualifications Regazzoni - having realised the second best time - will write off one of the two cars, so that Stommelen/de Adamich, having realised the second best time, are the lonely starters at the wheel of a new Alfa. 
The 33TT12 is seriously faster than the 440bhp strong 33TT3 of previous year (cf. the blue car on the left pics) and handling seems much better, but due to the strike of the Italian metalworkers, the development remains unfinished. Eventually Autodelta will send two cars to the Nürburgring 1,000-kms where both will be retired with motor problems. Then it is decided that the new car will only be raced next year.
Meanwhile Autodelta mechanics will assist the 3.0 Alfa Romeo 33TT3 of the Scuderia Brescia Corse - an ex-works car, now painted in light blue and white (cf. picture of the car with #60) at the rounds it enters. At the Le Mans 24 hours the 33TT3 will be third after 16 hours of racing, before being blocked in the pits during two complete hours. Nevertheless the old car will finish the race as 15th.

              3.0 Matra-Simca 670B
Not Alfa Romeo, as it was the case in 1972, but Matra is the main challenger for Ferrari this year. The French team will use during the season six chassis. Three of them will be equipped with the 485bhp at 11,500rmp 60°V12 MS73 engine of 2,999cc, a no detuned F1 engine to be used at the 1,000-km races. By using larger valves and four exhaust pipes "3 in 1" not only the power output but also the torque is considerably improved. The new motor is early in the coupled to an ultra light Hewland DG300 F1 gearbox on one car and on a heavier ZF on the other car's). But later in the season a new gearbox, a synchronised box, derived from the famous 917, and made by ...Porsche (a "Type 1983") will be mounted on all 670B cars.
On advice of Goodyear - not only Ferrari's tire manufac-turer, but also Matra's - the 15" diameter rear rims are replaced by smaller 13" rims equipped with 17" tires. Contrary to the former MS670, still raced at this year's Daytona 24 hours, the Girling brakes - full ones, no longer the ventilated bigger ones - are no longer within the rims (Matra rims for the fronts, MEL rims for the rear slicks and BBS for the rear rain tires) but fixed to both sides of the gearbox. Weight of the MS670B (pic above right) for the 1,000-km races is down to 690 kgs. The three cars with the new MS73 engine use the chassis of the previous year with a aerodynamically transformed MS670B bodywork. Only at the first round in Daytona the not already transformed MS670 (however with the new engine) will be used.
The three Matras MS670B for Le Mans (pic at the middle) will be equipped all three with a new chassis and with the slightly detuned 60°V12 MS72 engine, 450bhp strong at 10,500rmp. Weight of those cars is 714 kgs, dates very similar to the Le Mans Ferraris 312PB using a slightly detuned 180°V12 boxer motor with an equally performing 450bhp at 10,500rmp motor for a weight of 690 kgs. For Le Mans there is also a MS 670 conserving the ZF gearbox and the larger 15" diameter rear wheels where the brakes are still mounted within the rims. Motor here is a 450 bhp MS71/72 with titanium rods.
Jean-Luc Lagardère opts for an all-France racer's team with Beltoise/Cévert on the first car and Pescarolo/La-rousse and Jabouille/Jassaud on the other cars. For Le Mans Depailler/Wollek will be added at the fourth car.

             3.0 Mirage-DFV M6 Ford V8
Having much more restricted financial means than Ferrari, Matra and Alfa Romeo, John Wyer - twice winner of the WCM with Porsche in 1970 and 1971 - continues his efforts to make of the Mirage M6 a winner. Initially he has good hope that the Weslake V12 motor (announced for 460bhp at 10,600rmp) will be the correct solution. He lets design a closed version of the M6 and will show with it at the Le Mans April trials. However, the motor seems to be a pure disaster (resulting in a trial with Harry Weslake). So Wyer and John Horsman decide to continue with their previous year's Mirage M6. Motor is a F1 Cosworth 90°V8 2,993cc good for a 460bhp output at 10,000rpm. Gearbox is a Hewland F1 at the 1,000-km races and a ZF5DS/25 for Le Mans. Here the motor is restricted to 9,400rpm. Main problem remains the overweight of the car: 750 kgs. The body as been reworked by Len Bailey with a rear inspired by the Porsche 917K. A two car entry per round is scheduled (with exception of the Targa Florio). As racers Derek Bell, Mike Hailwood, John Watson and Howden Ganley (ex-Matra) are engaged. Vern Schuppan is the substitute driver.

           3.0 Porsche Carrera RSR
Contrary to last year there are nearly no innovations in endurance racing. One exception is the 3.0 Porsche Carrera RSR as raced by Martini International Racing and fully backed by the Porsche factory. It is a works car homologated in Group 5. It is derived from the 2.8 Porsche Carrera RSR Group 4 car, manufactured at 49 copies. To lower its weight Porsche Zuffenhausen uses glass fibre parts for the body. "The first example, chassis R1, was completed in November 1972 and tested extensively by Porsche at Paul Ricard, the next (R2) being built up shortly afterwards. Weighing in at 830kg, 70kg less than the 2.8 engined RSR, wider rims and tyres dictated some minor suspension geometry revisions although the most significant developments were made underneath the rear lid. Three different engines were used during that 1973 season, initially Porsche's 308bhp Typ 911/72 motors from the 2.8 RSR seeing service, these soon being replaced by a more potent 3-litre Typ 911/73 engine with 2993cc and 315bhp. Later on in the year, even hotter Typ 911/75 motors with 330bhp were used, but in any guise, these very special factory hot rods were fantastically quick - as illustrated by many top endurance drivers of the day who often found them to be a match for sports proto-type class machines that were becoming ever further removed from genuine road-cars. Beginning with body-shells that were visually almost identical to those of the 2.8 RSR, it was not long, however, before Porsche’s rolling laboratories with their super-lightweight panels began sprouting some wild aerodynamic aids, this all being perfectly legal now they were freed from the production-esque constraints of Group 4 regulations. Wheels and tyres got progressively wider as the year wore on which necessitated greater flaring to the wings, the 2.8 RSR's more or less standard duck tail spoiler being replaced by a huge wraparound aerofoil soon after the opening round. Looking absolutely stunning in their predominantly silver Martini & Rossi liveries, these prototype class machines were driven by some of Por-sche’s most highly regarded factory drivers during 1973, Gijs van Lennep, Herbie Muller, Leo Kinnunen and George Follmer all having starred."

           3.0 Lola-DFV T282 Ford V8
After Joachim Bonnier's fatal accident at the 1972 Le Mans 24 hours, Lola has no longer a works team in endurance racing. Eventually the Scuderia Filipinetti will enter in 1973 a semi-works team, entering the slightly modified Lola T282 at some rounds of the WCM with Jean-Louis Lafosse and Reine Wissell as drivers. The car is equipped with a 90°V8 Ford Cosworth DFV 2,993cc motor, 470bhp strong at 10,900rpm coupled to a Hewland DG300 gearbox. Weight of the car is 700kgs.
At Le Mans the team will mount another rear wing, no longer integrated in the body. Racing a not detuned F1 Cosworth motor the Scuderia Filipinetti will struggle during the whole season with problems of reliability.
Some privateers will also enter the Lola-DFV T289/T282 being an upgrading of last year's T280. Road holding and handling of those cars, combined with a too low reliability, make that they'll score rather poorly at the 1973 World Championship for Makes. A sixth place at the Vallelugna 1,000-kms and a sixth place at the Dijon 1,000-kms are the lonely obtained finishes at the WCM, where the T282 was more than once preceded by the 2-litre T290 and T292.

          2.4 Lancia Stratos HF P
A real works car is the Lancia Stratos HP prototype entered by Cesare Fioro for Jean-Claude Andruet and Sando Munari at the Targa Florio. The car is equipped with a 2,418cc V6 Ferrari Dino motor, developing 320bhp at 8,500rmp. Weight is 850kg. Essentially a rally car, the Stratos prototype is excellent on tortuous roads as those of the Targa Florio, where it will finish as runner-up. "The futuristic, and radical, styling was the result of extensive wind tunnel testing to achieve the minimum possible coefficient of wind resistance, and produced a vehicle which looked more like something from a Sci-Fi movie than a realistic super car. In fact, the name Stratos is reputed to be given because one of the designers thought the car looked like something which had come from the Stratosphere!"

     3.0 Duckhams-DVF LM Ford V8
Another car which will only be entered at only one round of the 1973 WCM (just as the Lancia Stratos HF) is Alain de Cadenet's Duckhams LM seen at the Le Mans 24 hours. The car is equipped with a detuned 450 bhp 2,933cc Ford Cosworth DVF 90°V8 motor, coupled to a Hewland DG300 gearbox. Weight of the car is 675 kgs. Compared to the version of previous year the car has a longer tail section and a redesigned nose section bordered by fins. Motor is the ex-Ligier owned DFV 11 series rebuilt by John Nicholson.
Contrary to last year, where the Duckhams caused a stir at Le Mans by fighting long time for the third place, the 1973 version will not succeed to perform as well.

               3.0 Porsche 908-03
Although already four years old the Porsche 908-03 is also this year still active in endurance racing. There is the 908-03 owned by Reinhold Jöst and the 908-03 owned by the Escuderia Montjuich, which, during the course of the season will change it's Tergal sponsored yellow body for a chocolate Toblerone body.
Both cars use a 1970 Porsche 2,996cc 8-cylinder 2 valves boxer engine developing 380bhp at 8,4000rpm.  The cars are equipped with 13" rims, in the case of Jöst equipped with 9" Firestone fronts and with 16" Firestone rears; for the Escuderia Montjuich that are 9" Goodyear fronts and 15" Goodyear rears.
The Montjuich owned 908-03 is also entered at some rounds of the WCM by the Porsche Club Romand for Claude Haldi and Bernard Chevenière. When Juan Fernandez is free from racing duties for the Escuderia Montjuich he joins Haldi at the wheel of the car.
Reinhold Jöst has just as last year Italy's Mario Casoni as team mate and Marc Blancpain as substitute driver. The Escuderia Montjuich uses Juan Fernandez, Francisco Torredemer and Bernard Chevenière (when he is free from racing duties for the Porsche Club Romand).
Of all S3000 Group 5 cars seen in competition the 908-03 is by far the lightest car with its 650 kgs. But even then ballast must be ...added to reach that minimum weight. One remembers that the original 1970 version had only a weight of 500 kgs.

               3.0 Porsche 908-02
Already five years old the Porsche 908-02 is still present at the 1973 World Championship for Makes. At the Daytona 24 hours Harry Bytzek's Flunder will be present. At the Monza 1,000-kms and the Le Mans 24 hours we find André Wicky's 908-02 at the start. And at the Le Mans 24 hours a team from Ecuador brings a 908-02 at the start to finish seventh overall with it!
The Porsches 908-02 are equipped with a flat 8-cylinder Porsche engine developing 350bhp at 8,400rpm.
With a maximum speed of 280 to 290 kph the 908-02 is certainly handicapped as compared with the other S3000 cars, all able to go over 300 kph (with 320 kph for the Matras and the Ferraris).

1.2. GROUP 5 S2000 CARS

               2.0 Lola-FVC T292 Ford
Eric Broadley's new Lola T292 differs essentially from last year's T290 by the rear wing being integrated in the body. The new car is equipped by all kinds of 2-litre motors, but the most popular remains the 1,974cc Ford Cosworth FVC, offering 265bhp at 9,000rpm. In such configuration we'll find the two Lolas T292 of the Écurie Bonnier, entered by the Portuguese Team Bip for Carlos Santos, Santos Mendoza, Carlos Gaspar and Jorge Pinhol. A similar car of the Écurie Bonnier, raced in the old yellow and white colours with the red stripe in the middle will be entered for Ray Fallo and Jose Dolhem. Another will be entered once by Joly Club. Only the Team Bip Lolas T292 will enter several rounds (Monza, Francorchamps, Targa Florio, Nürburgring), but just as in the European Sports Cars Championship both cars will suffer from a lack of power and a lack of reliability.

               2.0 Lola-BDG T292 Ford
Barclays International, since last year with success involved in the European Sports Car Championship, changes its T290 for the new T292. The new machinery will be entered at the Dijon 1,000-kms for Guy Edwards and Jim Busby. The car is no longer equipped with the Vega EA engine but with the new 1,990cc Ford Cosworth BDG, developing 275bhp at 10,000rpm. Weight of the car is 610 kgs. It is a very fast 2-litre sports car, which is proven by the seventh place on the grid at the Dijon 500-kms. At the 1973 European Sports Car Championship Guy Edwards will win two rounds out of eight with it: the Trophéés d'Auvergne at Clermont-Ferrand and the Coppa Citta di Enna.

         1.9 Chevron-FVC B23 Ford
Several private racing teams - among them Red Rose Racing, Ember Racing, Shierson Racing, Promo Advertising, Scuderia St Paul, Escuderia Montjuich, Squadra Tartaruga, Scuderia Atenco etc. - having bought the new Chevron B23, have plans to let them be raced not only at the European Sports Cars Championship, but also at one or more rounds of the WCM. Some of the used B23 are upgraded B21 cars. Motor is in most cases a 1.9 Ford Cosworth FVC of 1,930cc, delivering 255bhp at 9,000rpm. But several - mostly British - tuners achieve up to 275bhp by increasing slightly the motor capacity, by using larger valves, by using other exhaust systems, etc. Weight of the Chevron-FVC B23 oscillates between 595 kgs to 630 kgs. Some teams use also other motors such as the Vega EA (being fast but fragile) or a BMW 2-litre tuned by Schnitzer or Alpina.
The new Chevron B23 will be seen at the Daytona 24 hours, at the Vallelugna 6 hours, at the Francorchamps 1,000-kms, at the Targa Florio, at the Nürburgring, at the Le Mans 24 hours, at the Österreichring 1,000-kms and at the Watkins Glen 6 hours. Most successful racers are John Burton and John Bridges of Red Rose Racing (3rd overall at the Nürburgring), Martin Raymond and Peter Humble (on Martin's private car), Giovanni Morelli and Mauro Nesti (on the Scuderia St Paul's car) and Luigi Moreschi and Frank McBoden (on the Scuderia Atenco car, finishing 4th overall at the Targa Florio).

            2.0 March-BMW 73S
The new March-BMW 73S is raced with success since the Springbok Series of last year. Although rather designed to be used at the European Sports Cars Championship, the Ceramica Pagnossin 73S of Gabriele Serbin and Andrea de Adamich will be entered at the Monza 1,000-kms and the STP March Racing 73S of Bernd Keuhne and Roman Pechmann will be entered at the Watkins Glen 6 hours. At both occasions a March-BMW 73S will succeed to win a place among the top-10 at the grid, proving that the March is a very fast 2-litre car. Engine (with four valves per cylinder) is a 1,998cc BMW M12 4L of 278bhp at 9000rpm. Gearbox is a Hewland FG400. Weight of the car is 580 kgs.

        1.8 Chevron-FVC B21 Ford
Several privateers will enter the 1973 World Champion-ship for Makes at the wheel of last year's Chevron B21. This car with a dry weight of 490kgs (590 kgs in racing configuration) was originally equipped with a 1,790cc L4 Ford Cosworth FVC engine, delivering 245bhp at 8,500rpm. Private owners, however, will race them with all kinds of tuned Cosworth motors, up to the 1,974cc L4 engine, developing 255bhp at 9,000rpm. There exists also a 2.0 Chevron-BMW B21 version good for 275bhp at 9,000rpm. The 2.0 Chevron-Vega EA uses a Chevrolet engine of 1,999cc good for 268bhp at 9,000rpm. Most Chevrons B21 entering a round of the WCM will use the 1,974cc Ford Cosworth FVC motor.

            2.0 Lola-FVC T290 Ford
Several teams - most of them from Italy - decide to race last year's Lola T290 at rounds of the 1973 WCM. Weight of those cars (in racing configuration) is 580 kgs. Used motor is in most cases the 1,974cc L4 engine, developing 255bhp at 9,000rpm (the same as used in the most Chevrons B21). With such car, owned by the Scuderia Brescia Corse, "Pooky" and Gagliardi will finish fourth at the Monza 1,000-kms. Best performances, however, will be realised by the private 2.0 Lola-Abarth T290 as entered by Antonio Nicodemi and Silvio Moser at the Targa Florio (where they'll finish fifth overall) and by the Citta dei Mile for Giorgio Schön and "Pal Joe" at the Monza 1,000-kms (where they'll finish sixth overall). Those cars use the 280bhp Abarth motor as installed in the 2.0 Abarth-Osella PA1. The last cars will only be seen at the European Sports Cars Championship, not at the WCM.

         1.8 Chevron-FVC B19 Ford
Even the two year old 1.8 Chevron-FVC B19, with the 1,790cc Ford Cosworth FVC 245bhp engine is still raced in 1973. Switzerland's Peter Ettmuller and Walter Frey will finish 8th with it at the Nürburgring 1,000-km. In fact they race a B19, having been upgraded last year to a B21 and this year to a B23. Chassis however is a B19. Trevor Twaites and McInnerey will finish with a similar machinery twelfth at the Vallelugna 6 hours.
Even the three years old 1.8 Chevron-FVC B16, the closed coupe thus, will be seen at two occasions at the 1973 WCM. Racing Enterprises will enter such car at the Dijon 1,000-kms for Jose Juncadella and Javier de Bagration. And Professional Racing will enter a B16 at the Daytona 24 hours.

1.3. GROUP 4 (GTS) CARS

            4.4 Ferrari 365GTB-4
Several teams, among them Automobiles Pozzi (F), NART (USA), Écurie Francorchamps (B), J-C Bamford Excavators (GB) will enter the competition version of the Daytona Ferrari at such rounds as the Daytona 24 hours, the Fran-corchamps 1,000-kms, the Le Mans 24 hours and the Watkins Glen 6 hours. By finishing second at Daytona (whilst the Matra-Simca MS670 fails to finish) Ferrari will collect 15 unexpected points at the 1973 WCM. By doing so they'll enforce Matra to fight until the real last round to win the title. The Daytona Ferrari is equipped with a 4,390cc V12 four cams engine good for 435bhp to 450bhp. Weight of the car oscillates between 1,335 kgs and 1,350 kgs. Among the drivers we find François Migault, Milt Minter, Arturo Merzario, J-P Jarier, Teddy Pilette, Vic Elford, Claude Ballot-Léna, Sam Posey, etc.

            2.8 Porsche Carrera RSR
"The 2.8 Carrera RSR's were Porsche’s 1973 Group 4 contenders that, although based on the fabulous 2.7-litre Carrera RS homologation specials, featured a number of important upgrades for use on the track. Indeed, weighing in at the 900kg minimum weight for Group 4 cars, the 2.8 RSR had its suspension geometry altered front and rear to accommodate special coil springs with fully adjustable dampers, wider wheels and new tyres. Titanium hubs were also used whilst twin circuit ventilated and perforated brake discs were sourced from the awesome 917 sports prototype. Engine-wise, the 2.8 RSR's began life running hot Typ 911/72 engines, these units having been souped up and specially prepared versions of the Typ 911/83 motors as found in the 2.7 Carrera RS road car. The cylinder heads were now further apart to facilitate a bore stretch of 2mm, this itself having been possible thanks to Porsche's use of Nikasil cylinders with aluminium rather than magnesium castings. Meanwhile, new pistons, four bearing racing cams and twin plug cylinder heads were sourced from 1972's 2.5 ST. Displacement was up to 2806cc, output of these Typ 911/72 engines registering as 308bhp at 8000rpm - an incredible 98bhp up on the 2.7-litre road car! Compression had been hiked from 8.5 to 10.5:1 on the RSR although, for the time being at least, a not too dissimilar Bosch mechanical fuel injection was used. This endowed the RSR with a top speed of around 175mph whilst zero to sixty took less than five seconds, all of which made these 2.8-litre machines one of the most potent Group 4 machines around. However, it was this performance coupled with an excellent reliability record that made the 2.8 RSR such a formidable opponent to the likes of Ferrari's Daytona Competizione, De Tomaso's Group 4 Pantera's, the highly developed works-backed Ford Capri RS and Chevrolet's IMSA spec Camaro's. But visually, although appearing outwardly very similar to the Lightweight 2.7-litre RS, the RSR came with a number of easily identifiable features that help differentiate them from their smaller displacement road car siblings. Indeed, perhaps most obviously, the RSR's wheel arches were heavily flared at the front and back to accommodate those wider wheels and tyres which left the 2.8 with a markedly more aggressive stance."

         7.0 Chevrolet Corvette ZL1
Most Chevrolet Corvettes, raced this year, are equipped with the powerful ZL1 6,997cc V8 motor, developing 585bhp at 6,600rpm. That motor replaces the former L88 of 550bhp, having been manufactured from 1967 to 1969. Until last year some teams raced still the L88. Corvettes will be raced at the 1973 WCM at the Daytona 24 hours, the Le Mans 24 hours and the Watkins Glen 6 hours. They are entered by Troy Promotions, by John Greenwood, by Dave Heinz, by Murray Racing, by Chitwood Racing, etc. at the American rounds. At Le Mans 24 hours we'll find also French entries by Greder Racing Team and by the Écurie Léopard. Best result will be scored by Dave Heinz and Bob McClure at the Daytona 24-hours where they'll finish third overall. Weight of the car is over 1,350 kgs.

          5.8 Pantera de Tomaso GTS
Although no longer entered as a works car, the Pantera de Tomaso GTS is the only car which is able to beat the 2.8 Porsche Carrera RSR at two rounds of the European Grand Touring Championship. At Imola victory goes to Mike Parkes, responsible for the development. At Hockenheim Clay Regazzoni wins with the Team VDS Pantera. At the WCM Team Franco-Brittanic, using Guy Chasseuil and Jean Vinatier as drivers, will enter a Pantera at the Dijon 1,000-kms. And at the Monza 1,000-kms MoMo Racing Team will start a Pantera with Giampiero Moretti and Giancarlo Manfredini as drivers. At the EGTC the Jolly Club Pantera will finish third at the Monza 6 hours, and at the Tour de France (also an EGTC round) a private car will finish sixth. The Pantera GTS uses a 90°V12 5,763cc Ford motor, developing 485bhp for 1,120 kgs.

1.4. GROUP 2 (TS) CARS

               3.3 BMW 3.0CS
Since 1963 Touring Cars have their own European Touring Car Championship. Last year the ETCC was dominated by the works Ford Capri having won all rounds but one. This year BMW Motorsport will enter two factory cars of type BMW 3.0CS at the ETCC. Alpina and Schnitzer will enter similar cars. The factory cars use a L6 3,331cc BMW M52/2 motor good for a power output of 375bhp at 7,600rpm. Weight of the works car is 1,079 kgs. It will be a great success. The Schnitzer and Alpina BMWs are good for 360bhp at 7,500rpm for nearly the same weight.
Since last year Group 2 Touring Cars are also allowed to enter several rounds of the WCM. At the Francorchamps 1,000-kms BMW Alpina will enter two cars for three drivers: Niki Lauda, Hans-Joachim Stuck and Brian Muir. Tey'll finish seventh and eighth out of twenty-seven starters. At the Nürburgring BMW Motorsport enters two cars, now for Chris Amon/Stuck and for Dieter Quester/Toine Heze-mans, the last named pairing finishing ninth. At the Le Mans 24 hours the same works cars are entered for the second time with the same pairings. Hezemans and Quester will finish eleventh overall, winning their class. The other car plus a privately entered car are retired.

           3.0 Ford Capri RS2600 LW
Having won last year all rounds but one at the ETCC and having finished 10th and 11th at the Le Mans 24 hour, Ford Motorenwerke seems having underestimated the works BMWs this year. With their 2,999cc 60°V Ford-Weslake 151 motors of 327bhp at 7,600rpm for a car of 973 kgs they are a bit short in power as compared to the new works BMW 3.0CS. As long as the rear wing on the BMWs is not homologated the Capris can defeat BMW, but once they're equipped with a spoiler the Capri hegemony is over. The works Capris are entered at the Nürburgring 1,000-kms where Birrell/Fitzpatrick finish 6th overall, winning their group. At the Le Mans 24 hours Glemser/Fitzpatrick qualify as 20th, faster than all GTs (Ferraris and Corvettes included). They deliver a gruelling combat with the work BMWs, being 10th overall after 7 hours, but will have to retire.

       7.0 Chevrolet Camaro Z28 ZL1
Using the same motor as the Corvette - 585bhp at 6,600 rpm - only the American Camaros are competitive. In Europe only Ivo Grauls raced a 7.4 Camaro (in 1971). It took regularly the pole but reached never the finish at the ETCC. The following years European Camaros race without success 5-litre motors.
American 7-litre Camaros Z28 are not only entered at the USSCR but also at the Daytona 24 hours and the Watkins Glen 6 hours. A 7th place at Daytona and a 10th place at the Glen are the best results. Weight of the car is 1350 kg. European Camaros will not be seen in competition at the 1973 WCM. Their reliability is highly doubtful, certainly at long distance races.

          2.0 Alfa Romeo Giulia GTAm
At the ETCC Autodelta will race the Alfa Romeo Giulia GTAm in Division I. There they use the 1,999cc L4 Alfa engine developing 215bhp at 7,400rpm. It's a 2OHC with two valves per cylinder and Lucas fuel injection. Weight of the car is 970 kgs, just as for the Capris. Seriously handicapped in power the works GTAm finishes at the ETCC 5th at Salzburg and 4th at the Nürburgring 6 hours. 
Having too many problems with the Group 5 Alfa Romeo 33TT12, Autodelta has no time to enter their GTAms at rounds of the 1973 WCM. Where this is done, such as at the Targa Florio and at the Nürburgring 1,000-kms, it concerns private owned Alfa Romeos Giulia GTA (twelve at the start of the Targa Florio!), and only in two cases a new Giulia GTAm. One of them, entered by Maurizio Zanetti (for himself and for Achille Marzi) will reach a top-10 rank at the Targa Florio.

¶2. SURVEY OF THE 10 ROUNDS OF THE 1973 WCM

A good survey of te 10 WCM rounds can be found here...