Talking Group 2 here and production based touring cars so here comes the Cologne Capri, the fastest and meanest evolution of the model. The final answer from Ford to the mighty BMW CSL which had taken the game to another level back in 1973.
Ford and their Cologne, German based Group 2 effort put together a new Homologation as well as a complete new car from engine to drivetrains in order to take back the title for 1974 and here is the full story of how the project came together.
History and regulations are both to be considered as to why Ford had to introduced a whole new Homologation in order to tackle the BMW’s European Touring Car Championship contender, the 3.0 CSL. BMW had been clever in their Homologation when introducing their car, it had been homologated in the over 3000cc class with an original engine displacement of 3003cc. This permitted the engine capacity to be increased to a maximum of 3500cc which they did and which was no object to the enforcement of the rules.
Regarding Ford, the RS2600 Capri which had been ruling the championship for some time now but which faded away in 1973 and against the Munich effort had been homologated in the up to 3000cc class which meant that according to the rules, there was no way they could match the BMWs in terms of engine capacity. Also and while the RS2600 was a wide bodied production based car, BMW and the CSL took it to another extent in terms of aerodynamics with a car that sported a complete aerodynamic package with front spoiler and rear wings. The edge that BMW had built was too much for Ford and the 1973 Championship went to BMW.
For 1974, Ford knew they would need a so-called “Homologation Special” in order to compete on the same ground and in November 1973, the RS3100 Capri was introduced to the public. 200 were produced at Ford’s Halewood, UK plant with an Essex V6 now enlarged to 3091cc and a huge ducktail spoiler. On 1st of January 1974, Homologation for the RS3100 Capri was approved by the FIA in Group 2 and Ford had everything in hand to tackle the 1974 ETCC Championship with an engine and aero package that would match the trend established by BMW.
A lot of work went into the RS3100, Mike Kranefuss, head of the Ford program decided to drop the Cologne built V6 and instead hired Keith Duckworth from Cosworth in order to design some new 24-Valves head to fit the Essex V6 and enhance the power range to more than 400 horsepower. Regulations would allow alternative heads to be fitted for 1974 if produced to a minimum of 100 examples and this would definitely be needed in order to match the so-called M49 head being developed by BMW.
Thomas Amerschlaeger, Ford Cologne head of engineers had the task of building the new race car. All cars were started from basic LHD steel bodyshell and fitted with new front and rear wheel arches. Suspension was re-worked and fabricated mainly of aluminium or magnesium in order to save weight. The front assembly followed the already trusted previous Capri practice, Bilstein gas-filled shock-absorbers were used but rubber front strut mounts were replace with aluminium ball-joints. Magnesium hub-carriers were fitted all round to reduce unsprung weight as well as “export” heavier suspension plates and centre-lock peg drive wheels. For the back, Ford used the now common practice and interpretation of the rules which stated that suspension systems had to remain standard. It meant that the Capri had to use leaf springs but by using a plastic rear leaf spring and fitting shock absorbers and springs, they did retain the standard principle while using additional springs. The standard Capri beam rear-axle was used but located and held in place by four trailing arms and using a new axle cover which sported and adjustable transverse Watts linkage in order to control the rear roll-centre.
Braking was achieved through huge ventilated discs and ATE aluminium calipers fitted all round the car with help of a water cooling system which was developed and tried in order to keep all that as cool as possible. For the wheels, the Cologne Capri sported BBS split-rims secured by a central locking nut and wheel dimensions were only an inch or so from the ones used in F5000 at the time. Tyres were Dunlop slicks and the whole package permitted the Cologne beast to achieve some huge cornering speeds while carrying the usual and period correct Capri racing style of having two wheels wagging in the air !
Aerodynamics were now pretty important and the whole package of front and rear spoiler was shaped using a wind tunnel. The first test soon followed but only the chassis or shell was ready and it still sported the 1973 Cologne V6 by then. However, the test provided useful datas on the car aerodynamics which permitted Amerschlaerger’s team to fine tune the package. It was also found after the test that the Cosworth built GA-V6 would be a little bit heavier than initially thought and therefore, the front and rear balance of the car was re-worked with more ancillaries like the dry-sump oil tank being fitted in the car’s boot.
And last but not least, the engine known as the Cosworth GA-V6 had finally turned up. The engine assembly and design was the result of Mike Hall who had been linked to the Ford DFV Formula One unit in the past through the design of its ancillaries. Based on the Essex V6 engine, there was – and still is – a major problem from the start of the drawing board. As the engine capacity was to be increased to 3412cc through cylinders being bored from 93.66mm to 100mm, it was found that out of 200 blocks, very few could sustain the required machining. But that wasn’t enough to stop Hall and four bolts main bearing caps were designed in order to keep the engine block in one piece which proved successful. The heads which had to match the 24-valves requirement were of a pretty straightforward design and sported double over head camshafts and which were of course belt-driven. Minimum production requirement for these heads to be used was of 100 sets and 30 were apparently sent to Cologne while the 70 remaining would be sent and sold through Ford’s Boreham centre but well, these and like the M49 BMW head remain a mystery as they prove almost impossible to find today… Anyway, the whole assembly originally breathed through a Lucas fuel-injection system as for the previous and smaller engine seen in 1973 but switched to a Kugelfischer fuel-injection from mid-season. Original figures through winter development stated that the engine was capable of 420 horsepower which was later enhanced to more or less 450 with fine tuning. When it turned up, the engine was mated to the RS2600’s five-speed ZF gearbox and a 7.2 inch Borg & Beck triple-plate mechanism mounted within a magnesium bell-housing.
Further in season development went into the engine and ancillaries cooling in order to provide the best aerodynamic package and ensuring the needed reliability. As part of that package, the front of the car was blanked off in order to increase straight line speed and ensure the best airflow both above and under the car. Cooling radiators for the gearbox and rear axle were placed in the rear wheel arches left for gearbox and right for the rear axle respectively and that’s why early in the season the cars only sported relatively small naca ducts. The engine oil cooler had been put behind the front grille originally but with the front being blanked off, it didn’t work and it was the same for the rear mounted, back of the car, behind rear axle, like a diffuser water radiators system. The front spoiler had been too good at diverting the airflow and this resulted in the whole cooling assembly being mounted in a side-mounted package with radiators in front of the wheel arches by the Nürburgring round of the 1974 season. It really started looking more like a Group 5 than a Group 2 car..!
Inside the car, a lightweight racing seat was fitted, the driver’s office more or less looked like a standard car with instrument panel and steering column switches having been retained but that same instrument panel now only sported dedicated competition instrumentation, lights and switches with a tiny control panel being fitted on the right hand side of the driver’s seat and next to the brake balance lever with the start button right there. Ford was now ready to tackle BMW on the same ground, oh yeah !
There’s one for sale and probably is the best piece of kit if talking about touring car madness. Known as GAECNA19997 or the first test mule for Homologation and development and then the back-up car. It served its purpose up to the 1974 Zandvoort Trophy where it debuted by winning the race in the hands of Mass and Stommelen. It continued winning at the Hockenheim DRM round in the hands of Klaus Ludwig but only finished 6th at the Norisring in the hands of Lauda later on. It’s also the one who took the last win in the ETCC for Ford, Cologne as well as the works effort at the Jarama 4 Hours with Heyer, Ludwig and Hezemans. Two wins out of two entry in the ETCC as well as a DRM win, well that ain’t a bad history also considering the drivers.
And last, if you are looking at more information on Group 2 Touring Cars and the European Touring Car Championship and its golden era, we recommend you the Touren Wagen Europameisterchaft book by Sportfahrer Verlag/Automobilsport.