Industry insight: Ford Sierra Cosworth RS500

Tickford’s time trial

Although robotic mass production, preferably measured in millions, is seen as the only profitable avenue for multi-national car makers, Great Britain plc has found alternative ways to make money from the car business.

Selling circuit expertise is exemplified by March Group plc becoming the first racing car manufacturer to go public on a capitalisation exceeding £14 million. Lola, Reynard, Van Diemen and many more sell significant chassis quantities overseas.

Grand Prix expertise tends to be sold on an individual basis for truly enormous sponsorship sums which back the efforts of Williams, McLaren, Tyrrell et al. Some transfer of speedy technology to the motor industry is typified by Lotus, whose work on active suspension and 16-valve engines extends to many clients beyond their GM masters.

This country’s creative, but above all winning competition technology does not cease at the borders of single seater racing. TWR at Kidlington does not just run the strictly “not for sale” winning Jaguars. Tom Walkinshaw’s empire also has a contract with General Motors Holden in Australia to develop high-performance road cars, currently racing them intermittently.

The United Kingdom sporting sale continues when exchanging Armco barriers for twisting mountain tarmac. Silverstone-based Prodrive prepares BMW’s M3 for national and international rallying and has already won the Corsican World Championship event. In view of all this successful diversification it is surprising that few British manufacturers have followed Lotus in the creation of an independent R&D department which is prepared to accommodate outsiders. Yet there is a loophole in the Lotus strategy which another prestige British name has quickly exploited: a lack of production facilities for the ideas created.

Imagine yourself as a Jaguar executive charged with responsibility to make just several hundred Cabriolets. Or a Freight Rover man looking for a small run of V8 Sherpa vans, such as fit the bill for police, ambulance and rallying servicing needs.

Or perhaps you are from Ford. Where do you arrange the road civilisation and legislation of an outright rally car? Road development of the RS200 was impossible when Ford’s engineers were overloaded either with immediate competition or the design and development of million-sellers.

To meet these restricted-run production needs Aston Martin Tickford has utilised its historic Midlands site at Bedworth to implement the work of 130 engineers and administrators based at Milton Keynes.

Independent of the (Victor Gauntlett 25%, Livanos 75%) family-owned Aston Martin since 1984, Aston Martin Tickford is one of 15 companies owned by CH Industrials today . . . And CHI, 100% owners of a company generally simply referred to as Tickford, started on the trail to annual £100-million conglomerate turnover status from the old Coventry Hood base at Bedworth, which I inspected recently.

My purpose was to see another example of what Tickford managing director John Thurston terms his company’s “unique design, development, test, homologation and small run production facilities.”

In a contract worth “more than half-a-million pounds to Tickford”, Ford of Britain entrusted that company with the task of bringing 500 Sierra Cosworth RS500s to reality. The competition and public sales debut dates were set at August 1 from the unglamorous Bedworthian premises, which had been allowed twice as much time to convert the RS200, which went on to production at Reliant.

Taking the Sierra RS Cosworth as the basic vehicle of their Group A racing and rallying ambitions, Ford had set aside 500 of the last 1986 vehicles from their Genk, Belgium, plant. These completed cars were shipped to Britain and stored in an outside compound in the Essex flatlands.

Ford created the car under the Evolution ruling which allows a further 10% production of the 5000 annual minimum imposed in Group A internatinal competition regulations (though the Evolution process is no longer recognised for international rallying,. Thus every change made emphasises the Cosworth RS model’s racing speed, enhanced air cooling and stability — the latter achieved through aerodynamics and relocation holes to remount the trailing-arm rear suspension.

For the road customer £19,950 buys approximately 10% extra power (224 bhp at 6000 rpm), no perceptible torque bonus and massive stability improvements through downforce created via a secondary rear wing and revised front end.

The penalty is that the five enlargements of engine and braking air supplies at the front end have increased the drag factor, and the enlarged turbocharger and intercooler raised the rpm needed to obtain maximum torque.

The assembly process started with Ford transporting complete cars to Tickford in Bedworth. The vast majority of the 500 were in black: just 52 white and the same nurnber of moonstone blue were built.

The first cars completed were four white prototypes registered in Essex and delivered in December 1986 with Ford and Tickford prophecies of the production car. However those prototypes were not built on the five-line, four work-station production system, one which made the RHD-only cars for the public.

John Thurston recalls how the development responsibilities were assigned. “Before production commenced we made ten cars, prior to the official Ford sign-off on July and these were completed in June.

“Cosworth at Wellingborough started delivering production engines in April, but we had already been asked to package the new motor and its bigger turbocharger, re-positioned and larger intercooler, new plenium chamber and extensive inlet-tract revisions, plus complicated electronics to serve the secondary fuel injectors.

“All drawings were our responsibility and our tasks also included engineering the car to meet EEC 1504 emission requirements” The secondary injection system is not activated on the public sale cars: a new microchip “brain” will be used in competition, or for those determined to extract the 400 bhp potential.

Mr Thurston continues: “All type approval requirements, some basic body engineering to make sure the extra aerodynamic features remained in position at 150 mph (calculating their weight and checking proper fixture to the body), plus a number of proving-ground tests were also assigned to Tickford. “Initially we did not complete the full Ford mainstream test distances, but in separate chunks it has amounted to much the same thing. We logged over 30,000 high-speed durability miles, plus thousands over rough pave.

“Naturally, a prime concern was that the tightly-packed engine bay should remain cool with that bigger turbo installed. I’m glad to say the car passed all cooling tests with flying colours,” he concludes.

Maximum production was reached during July and the company was on schedule to show FISA representatives (actually drawn from RACMSA following an earlier routine check from a BMW Motorsport senior engineer) the allotted 500 on July 30.

I called three days prior to that inspection and followed the progress of five parallel production lines and 44 men. Most were recruited in time to build those June “training cars” which consequently served a number of purposes, five requisitioned for Ford’s Press fleet.

Feeding into the plant from an outside compound, the process of turning an RS Cosworth Sierra into one of the RS500 breed was tackled in four primary stages. These followed the difficult de-waxing of vehicles which had stood for months in open air storage.

The first mechanical stage amounted to stripping out all that would not be required in the later incarnation, bar the engine. At that first work-station, the rear spoilers grew with the secondary RS-parts-sourced lower item and the “Gurney flap” 30mm extension to the upper wing (which contributes to downforce of more than 200 lbs at 100 mph).

Minor work includes a cut-out to clear the lower spoiler from fouling the upper wing pylon. Which made me wonder how Fokker ever built those effective triplanes nearly 70 years ago? Also Bedworth-fitted was an electrical over-ride to ensure that the radio aerial retracted when the boot opened, otherwise it would tangle amongst the lower wing extensions.

The second move saw the Sierras hoisted and the engines removed to a side assembly area which also built up the considerably altered front spoilers/bumper units. The original engines donated some ancilliaries, such as alternators and clutches, but many friction plates were damaged owing to transporter driver abuse. Front spoilers lost their standard spot lights in favour of wire-grilled ducting apertures. All the standard components, incidentally, including the basic 204 bhp Cosworth motors, were returned to Ford for spares/resale use.

For future authenticity, it is worth mentioning that a serial number unique to this Sierra series is applied low on the engine block, behind the dropped alternator mounting plate.

A third work station saw the 16-valve dohc motor wearing its T031/T04 oversize turbocharger bolted back in place, surrounded by a maze of new componentry and replacement heat-shielding of Tickford origin.

Under-bonnet details also included careful clipping of all cables and pipes away from chafing or heat damage, and the nearly full-width intercooler replacing the small standard item, attached behind the main water radiator, instead of on top.

The final stages were devoted to applying RS500 badges on both sides, plus the tail badge. The “splitter” extension to the front spoiler was stowed in the boot because it could so easily be damaged in loading to a transporter. . . Early RS500 drivers reported a vulnerability to parking damage anyway!

There were two stages of quality control, neither staffed by Ford: first a static inspection, then an eight-mile road test followed by another inspection. As Tickford manufacturing manager Brian Tennant explained: “We are responsible for all quality control, so any defect has to be caught at these stages. If there is a problem cars can go into a rectification bay, before sweeping back to us for a final, final inspection.”

A last look at the gathered double-decker tailplanes of 500 Sierras, and I climbed into a loaned 204 bhp Tickford Capri for a thoughtful ride home, piloting a 140 mph reminder of an era which has now drawn to a close for Tickford as well as Ford. Just 100 of the radically converted Capris were completed at the close of production.

Now Tickford is clearing the decks for “another limited production special we cannot discuss.” One more facet of Great Britain plc’s thriving small-scale, high performance renaissance. JW