ESCORT COSWORTH
We speak to Steve Harper, the man who designed the legendary Escort Cosworth, to find out exactly how Ford came to produce such an icon.
How the humble Mk5 gained its wings.
WHEN DID YOU FIRST HEAR ABOUT THE ESCORT COSWORTH PROJECT?
After working closely with Ford while at MGA Developments in Coventry on the Escort van, Galaxy/VW Sharan and Mondeo projects we were approached by Ford to help out with the design of another new car. This time it was for a project from Ford’s Motorsport Division, who desperately needed a car to replace the Group B RS200 and to follow on from the early rallying successes of the Sierra RS Cosworth.
I went to Dunton with Peter Horbury (MGA design director), Ron Saunders (MGA project manager), and Mike Gibbs (MGA managing director) to meet Stuart Turner, Rod Mansfield and John Wheeler from Ford’s SVE department. We were briefed on the new CE14 (Mk5 Escort) project, codenamed ACE-14, an all-new rally car based on a modified Sierra Cosworth floorpan.
I can still remember to the excited look on Mike Gibbs’ face as we broke for lunch. He was a great motorsport fan, running an old Frazer Nash race car himself. Mike that came up with the in-house MGA name for the project: ‘Feral’ – the domesticated cat gone wild! That truly summed up the spirit of the brief for the car we had been given.
WHAT WAS YOUR FIRST INVOLVEMENT WITH THE PROJECT?
My first sketches were based around an initial package developed by Ford SVE and Karmann, and as such stuck religiously to the brief.
John Wheeler wanted a huge cooling capacity for the car as, ‘at 100 mph sideways in the dust of the Acropolis Rally it gets pretty hot under the bonnet’. So I designed in plenty of intakes and outlets, along with the bonnet bulge for the engine to ensure the cooling criteria were all met. I also included John’s patented cut-away corners of the front bumper, which controlled airflow and increased the downforce. This feature became more common later on and was eventually used on the Escort EVO and Focus rally cars.
WHERE DID THE PROJECT GO FROM THERE?
“While I was drawing the initial sketches a mock-up rolling chassis had been hand built at Karmann in Germany. This was then delivered to MGA in Coventry. Together with my team of modellers we created the design for new bumpers, fenders, bonnet features and undertrays in modelling-foam and aluminium
sheeting, ready for the first wind tunnel testing. The rear wing was seen as an especially critical part of the design. John Wheeler always rated the effectiveness of the whaletail spoiler on the early Sierra Cosworth and RS500, it provided around 70-80 kg of downforce at 100 mph. For the Escort he felt 40-50 kg would be sufficient, but he wanted to have downforce both front and rear so the angle of the wing would be critical. To give the best drag/ downforce compromise this would then require major aero detailing and refinement. Dieter Hahne at Ford Motorsport had provided me with the necessary wing profiles.
HOW DID THE MODEL PERFORM INTHE WIND TUNNEL?
The aero model took about seven weeks to build, and when it was finished we shipped it over to Ford’s wind tunnel at the Merkenich