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Home of the Crystal Blue Sierra Cosworth

Sapphire 4x4

In 1990, Ford had worked out how to attach permanent four wheel drive to the Cosworth engine.

Ford hadn't done very well on loose surface rally stages with the rear wheel drive Cossie, partially because that's not what it was built for, but mostly because the competition from Lancia's Delta Integrale and from Audi's Coupe Quattro, both of which were 4 wheel drive, was far too stiff.  On loose surfaces, 4x4 was the way forwards, literally, but Ford just didn't quite have it.  They did have the XR4x4 but it simply wasn't competitive due to it's under-powered, naturally aspirated boat anchor of a V6 engine.

 

When its time came to replace the brazen 3-door in motor racing, the rear wheel drive Sapphire did what it could on the loose surfaces and did admirably on tarmac.  The XR4x4 was politely asked to stay out of trouble and wasn't raced again.  Instead Ford developed the Sapphire's four wheel drive successor, imaginitively named the Sierra RS Cosworth 4x4.

For the most part, the 4x4 Cossie was the same as its predecessor but with few new tweaks and toys.  The big clues from the outside were the new 4x4 badges on the bootlid and front wings, and the bonnet vents which tastefully followed the line of the bonnet.  The engine had been tweaked to allow the turbo to spool up quicker, and the ECU was remapped to provide around 10% more power in order to overcome the extra weight and mechanical drag of the 4x4 system.  The gearbox had been replaced with a 4x4 version of Ford's new MT75 (Manual Transmission 75mm) gearbox which featured synchromesh on Reverse - the old one would crunch if you didn't wait before engaging Reverse.  The brakes changed to single pot calipers at the front and were upgraded to vented discs at the rear, and new interior fixtures such as footwell illumination, an optional electric sunroof, and a CD player made appearances too. 

Later models featured a catalytic converter to help fit in with the new 'green' ideal of motoring, and as a little 'joke', Cosworth had painted the iconic red cam covers for these engines in a fetching shade of green.  The final few examples rolling out of the factory in Ghent had completely body coloured rear spoilers, missing the black lip. 

By the time the last, 12,250th 4x4 Sapphire Cosworth rolled off the line in 1992, the Sierra's time had come to take a bow.  The all new, front wheel drive Mondeo was due to replace Sierra the following January, and the next Cosworth would be the Escort, that wasn't really an Escort at all.