Model Page

Ford Sierra Sapphire Cosworth

Production Run:


Production Date:

1988 - 1989


Ford Cosworth 2.0 Turbo In-Line 4


Ghenk (Belgium)


5.8 secs

Max Speed:

151 Mph

The Sapphire Cosworth was Ford’s attempt at an executive express designed to go head to head with the BMW 3 Series, Audi 80 and Mercedes 190e. With understated looks, fully loaded interior and seating five people in comfort the Sapphire Cosworth was more than a match for its rivals, and with a 0-60 of just 5.8 seconds and a top speed of 151 Mph the car would comfortably out perform it’s more exotic rivals.

Sapphire Cosworth 2WD

Sapphire Cosworth 2WD

Cosworth had agreed to produce engines for the original Sierra RS project on the basis that at least 15,000 engines would be produced. The original RS Cosworth production run was only 5,542, well short of the 15,000 engines that Ford were obligated to buy. With this in mind, even before the Sierra RS Cosworth had been put into production Ford started to investigate the feasibility of using the Cosworth running gear in a four door Sierra.

Whilst the first generation of the Sierra Cosworth received praise from every corner, criticisms that were drawn against the car related to the ostentatious styling and lack of rear doors. The same 1,993cc Ford Cosworth engine and running gear was installed into a strengthened four door Sapphire body shell, utilising the same rear wheel drive layout. At polar opposites with the original Sierra Cosworth the car lost much of its window dressing, the bonnet vents were deleted as was the whale tail this being replaced with a discreet small single vane spoiler mounted on the tailgate. The car sat lower than the Sapphire 2.0 Ghia upon which it was based and was fitted with unique to the model 15” by 7” inch wide lattice alloy wheels fitted with Dunlop D40 205/50 VR15 tyres.

Sapphire RS 2wd

Sapphire RS 2wd

The car featured the same Ford Cosworth YB 1,993cc in line four cylinder, the engine being built at the Cosworth factory based on the Ford Pinto. With a 16 valve head, Garret T03 turbocharger, air to air intercooler and Weber Marelli electronic multi point fuel injection system the engine developed 204bhp @ 6,000 rpm and 205 lb/ft @ 4,500 rpm. The engine was incredibly flexible and produced no less than 160 lb/ft @ only 2,300 rpm. An attempt was made to refine the engine to match the smooth BMW and Mercedes unit, a new piston design was featured that had a revised gudgeon pin mounting to limit engine noise on cold start up and a more durable single coil spring was used on the turbo charger damper.

At the front the car used MacPherson struts, coil springs, lower track control arms, anti-roll bar and telescopic dampers. The car featured independent rear suspension consisting of semi-trailing arms, coil springs and telescopic dampers and a 16mm anti-roll bar. The suspension configuration was developed through a series of refinements to produce a more civilised ride whilst retaining the excellent handling of its predecessor. The first generation RS Cosworth’s raised roll centre and steering knuckle were dropped and the castor angles revised. The Fichtel and Sachs dampers were softened and spring rates increased to provide a softer ride whilst not affecting handling. These changes helped the car provide a smoother ride and made the car less twitchy under heavy braking and at speed.

The RS was equipped with prestigious stopping ability, 283mm ventilated discs were fitted to the front and 273mm solid discs to the rear acted upon by four piston callipers. A Teves electronic anti lock braking system was installed as standard. Power was transferred to the rear wheels through a Borg Warner T5 gearbox and 7” viscous coupling limited slip differential.

The interior was based on that of the 2.0i Ghia and as such came fully loaded, no optional extras were available. The car came fitted with Recaro front seats in grey cloth, a leather trimmed steering wheel and gear knob, central locking, electric front and rear windows, electric mirrors, heated front and rear windscreens and a six speaker stereo system with a booster amplifier. To increase security a factory fit alarm and Chubb high security locks were installed, a notable increase in the amount of soundproofing installed made a great deal of difference to noise levels in the car.

Launched in 1988 at a price of £19,000 and production continued through until the start of 1990 when the Sapphire Cosworth was replaced with the RS Cosworth 4x4. The Sapphire Cosworth received rave reviews for the outstanding performance and superb handling, the car was commented on favourably for its build quality likening it to BMW standards.

The Facts


Ford Cosworth YBB





Compression Ratio:


Fuel System:

Weber Marelli Fuel Injection

Maximum Power:

204 Bhp @ 6,000 rpm.

Maximum Torque:

205lb/ft @ 4,500 rpm.


Borg Warner T5 - Manual 5 speed.

Top Gear:

22.8 Mph per 1000 Rpm.


Servo Assisted Ventilated Front Discs / Rear Solid Discs

Kerb Weight:

1,250 Kg

Max Speed:

151 Mph


5.8 Secs