Moffat’s Cologne Capri
The factory-built RS3100 Cologne Capri raced by Allan Moffat in the mid 1970s was Australia’s wildest V6 Capri. Today, it’s New Zealand’s wildest.
The factory-built RS3100 Cologne Capri raced by Allan Moffat in the mid 1970s was Australia’s wildest V6 Capri. Today, it’s New Zealand’s wildest.
The Capri RS3100 was the product of a heated arms race in the early 1970s in Europe between Ford and BMW. Ford had been victorious in the 1972 European Touring Car Championship with its German-built Capri RS2600, affectionately known as the ‘Plastikbombe’ because of its bulbous bodywork flares. It was also known for its evil handling, but the RS2600 nonetheless was effective enough overall to see off BMW’s stylish 2800 CS coupe. Perhaps it was the sense of shame in being beaten by such an imperfect opponent, but in any event BMW all of a sudden got very serious about winning the ’73 ETCC.
The now-classic BMW 3.0 CSL (which replaced the 2800 CS) formed the basis of an amazing Group 2 homologation special that would forever be known simply as the ‘Batmobile’, on account of its trademark huge rear wing. With the extra downforce from that outrageous aero package, and a potent 3.5-litre upgrade to the inline six-cylinder BMW engine, the Batmobile had the firepower to melt the Plastikbombe…
If it was to stay in the ETCC fight, Ford needed to respond. The existing V6 in the RS2600 (developed by British engine tuning house Weslake) was already at its upper limit bored to 2.9-litres, so Ford had to look elsewhere for the 40kW power increase required to match the BMW. The answer lay at Ford’s UK headquarters, where British-built Capris were fitted with a different ‘Essex’ 3.1-litre V6 – this slightly larger engine could be taken out to 3.5-litres.
Cosworth was charged with the task of developing the Essex into a BMW beater. At the time there was probably no better race engine company in the world than Cosworth, whose 3.0-litre Ford DFV V8 was the dominant engine in Formula 1 even though it was an eight year-old design.
A change to the Group 2 touring car regs for 1974 allowed for the homologation of nonstandard cylinder heads. This was an important factor, because it allowed Cosworth to incorporate its signature piece on the Capri engine – a pair of proper race engine-style quad-cam, four-valve aluminium heads, just like the ones on its F1 DFV V8. The four camshafts and the Lucas fuel injection were belt driven by toothed pulleys at the front of the engine. ‘Downstairs’, they beefed up the bottom end with a four-bolt main bearing arrangement.
While a 3.5-litre capacity was achievable, Cosworth’s design team felt that boring the blocks out that much might be stretching the friendship when it came to reliability. Instead, they settled on a bore size of 100mm, making for an overall
capacity of close to 3.4-litres.
But even at 3.4, the Cosworth GAA-V6 Capri engine easily met Ford’s brief of 400 horsepower (300kW) – the first engine they ran on the dyno saw 310kW. Before long the screaming FordCosworth V6 would be pumping out nearly 340kW at close to 9000rpm.
This masterpiece of British craftsmanship would be mated with precision German engineering. Allan Moffat’s car was not known as the ‘Cologne’ Capri because of his Brut 33 sponsorship from the year before, but rather because that’s where the Group 2 homologation Capri RS3100s were made – in Cologne, Germany, at Ford’s European competition headquarters.
Under the direction of chief engineer Thomas Amerschlaeger, the Germans exploited the Group 2 rule book to the limit. For example, those bulky rear guards are not merely for show or to accommodate the huge 16-inch wide wheels; they also house the engine’s water cooling radiators, one on each side of the car, mounted in front of each wheel.
Airflow was directed over the twin radiators via a complex array of louvres and apertures. These were designed for maximum cooling capability as well as an efficient airflow exit through the wheel wells.
The lengths to which Amerschlaeger went in order to have rear guard-mounted radiators illustrates how serious Ford was with this car. It was part of a concerted effort to offset the extra weight (the Essex engine was heavier than the old 2.6) over the front axle by moving, wherever possible, other components towards the rear. The gearbox/diff oil cooler pump is driven off the diff; the oil tank is in the boot. So that the mechanics could quickly check the oil levels without opening the boot, there’s an exposed pipe running outside the bodywork near the right-side taillight.
The Germans put a lot of thought into this car. Consider the way the automatic fire extinguishing system was designed: it was incorporated into the rollcage, so that in the event of fire, the retardant material would be pumped inside the roll-cage tubes and released into the car through a series of strategically located holes. By this method, the need for a myriad of additional extinguisher pipework was eliminated.
But when it comes to clever engineering, it’s hard to top the solution they came up with for the rear suspension. The standard Capri leaf-spring, live rear axle suspension design was no doubt one of the reasons the RS2600 ‘Plastikbombe’ had such uncivilised cornering manners. At first glance this looked to be an unsolvable problem, because under Group 2 regs the car had to retain its standard suspension medium. It meant that Amerschlaeger and his team were stuck with leaf springs, rather than the preferred coils. Or were they? The race version would indeed be fitted with leaf ‘springs’, but these were specially made items – they were made out of plastic; they offered no springing effect at all. That role was instead taken care of by a pair of beefy coil springs and Bilstein racing shocks. In its homologation submission, Ford labelled the coils
merely as ‘additional springs’, and the FIA gave it the green light!
The axle itself was fitted with fore and aft trailing arms, upper and lower, and a Watts Link – an arrangement not dissimilar to what was used on pre-New Generation V8 Supercars.
To stop the Capri, up front were a pair of huge – 305mm diameter, 25mm thick – ventilated discs and special lightweight ATE callipers. Interestingly, the brakes had ‘hydro-electric power assistance’, a system which used an electric pump to boost the brake fluid reservoir up before the fluid is valved into the hydraulic system.
The RS3100 represented such a vast improvement over the old RS2600 in so many areas that it was hard to believe they both came from the same Ford Capri model line. But how would the new car fare against the all-conquering BMW 3.0 CSL?
With the likes of Niki Lauda (already an F1 driver by then), Jochen Mass, Toine Hezemans and, interestingly, Dieter Glemser, the German ace who would co-drive Moffat’s Brut 33 Falcon at Bathurst later in the year, Ford did not seem to have any worries on the driver front.
Ultimately, though, the highly anticipated showdown between the 3.0 CSL and the RS3100 turned into a bit of a fizzer. By early ’74 the effects of the energy crisis were being felt: car makers were hit with falling sales and the need to make dramatic changes to their marketing strategies as the price of oil suddenly soared.
One of the consequences was BMW’s decision to wind back its racing operations. BMW’s departure left the Capri RS3100s virtually unopposed.
Yet even then an RS3100 driver did not win the championship. With a points system that favoured the smaller class cars, the title went to Hans Heyer in a Zakspeed Ford Escort RS1600. At least it was still won by a Ford…
With no opposition, there wasn’t much point in the factory team continuing with the RS3100 into 1975. The last time an RS3100 raced as a works entry was in a six-hour sportscar enduro, a round of the World Sportscar Championship, in South Africa in November, 1974. At the Kyalami circuit, Mass and Hezemans shared the car to fifth outright (behind four Le Mans-style sportscars) and first in the touring car class.
It’d be three months before that particular RS3100 raced again. That race was at Sandown in Melbourne, and the driver was Allan Moffat.