Ford Sierra RS Cosworth group A (1987)
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Home » Rally Cars » Ford Sierra RS Cosworth
1986_Sierra_Rally_slide.jpg Source Development chain
1984: Ford Sierra XR4i
1986: Ford Sierra XR4x4
1987: Ford Sierra RS Cosworth
1990: Ford Sierra Sapphire RS Cosworth 4x4
Development level
Group A
Group N
Production

On board: see video with Mark Lovel in Ireland rally '88
In rallies: see video

Specifications

Click here for tunning Pinto engine
Service manual
Group/Class A/8 Homologation number: B 286 and A 5323
Years active 1987 - 1989 Homologation start: 1/8/1986 and 1/1/1987
Engine
Type Cosworth YBB based on Pinto block, straight 4cyl, 4 stroke, petrol engine located front longitudinal
Capacity 1993 cc WRC: x 1.4 = 2790 cc (1987)
x 1.7 = 3388 cc (1988+)
Bore x Stroke (mm) 90.82 x 76.95
Compression ratio phase 1: 7.0:1
phase 2: 7.2:1
Output power - torgue 270 - 280 HP / 6800 rpm (1.1bar)
305 - 315 HP / 6500 rpm (1.4bar)
350 HP / 6500 rpm (1.8bar)
phase 1: 37.0 kgm (383 Nm) / 6000 rpm
phase 2: 41.6 kgm (408 Nm) / 4500 rpm
Main bearings 5 of 57mm diameter connecting rod distance between centers 128.5mm, big end bearing diameter 55mm
Materials block: cast iron 206.8mm deck height, 102mm bore spacing cylinderhead: aluminium alloy
Cams/valves 2 overhead camshafts (DOHC), belt driven. Red camshaft cover 4 valves/cyl. - 16 valves total. 37mm inlet valve diameter, 31mm exhaust valve diameter. 2 coil springs per inlet/exhaust valve
Aspiration garret T3 turbocharger with intercooler,
Weber Marelli electronic fuel injection.
1990: 40mm turbo restrictor fitted.
pressure: phase 1: 1.1 bar
phase 2: 1.25 - 1.8 bar
Ignition Weber Marelli electronic, firing order 1-3-4-2
Cooling system watercooled 7.5 lt
Lubricating system 3.8 lt
Transmission
Type rear wheel drive Getrag 240, 5 speed gearbox
Gearbox ratios 1st: 2.952/1
2nd: 1.937/1
3rd: 1.336/1
4th: 1.000/1
5th: 0.804/1
R: 2.760/1
1st: 2.337/1
2nd: 1.681/1
3rd: 1.358/1
4th: 1.150/1
5th: 1.000/1
Diffrential ratio 3.65/1, 4.008/1, 4.353/1, 4.680/1, 5.100/1 hypoid spiral bevel gear viscous limited slip rear differential
Clutch dry, single disk
Chassis-body
Type Steel monocoque chassis with roll-cage. 3 door coupe Phoenix-manufactured body kit with polyurethane and rubber body addition and rear wing to ford design, wheelarch extensions, side sills, front bumper/spoiler with flexible rubber
Front suspension macpherson strut with lower transverse arm and 28mm stabillizer, coil springs and telescopic gas shock absorbers
Rear suspension semi-trailing arm with coil springs, telescopic gas shock absorbers and 16mm diameter anti-roll bar
Steering system rack and pinion 2 turns lock to lock
Brakes ventilated disks with 4 piston calipers all around, 285/305/330mm front disk diameter, 285/305 rear disk diameter dual circuit with servo, adjustable ratio split front to rear
Dimensions
length: 4.458 m (175.5") width: 1.727 m (68.0") height: 1.377 m (54.2")
wheelbase: 2.608 m (102.7") front track: 1.452 m (57.2") rear track: 1.468 m (57.8")
Rims - tires gravel: 6" x 16" front, 7" x 16" rear
tarmac: 8 3/4" x 16"
gravel: 195/65-16" front, 215/65-16" rear,
tarmac: 225/65-16"
Weight 1130 - 1180 kg (1350 kg in Safari)
Weight/power 3.8 kg/HP
Fuel tank 50 - 70 lt

Results in WRC

Statistics

1986 1987 1988 1989 1990 1991 1992 1993 Total
Works
Races /wins 5 4/1 1 10/1
Entries/finishes 7/3 11/10 2/0 20/13 (65%)
Others
Races/wins 1 +3 +4 +6 5 4 3 2 28
Entries/finishes 3/0 21/11 27/8 20/9 9/3 4/0 4/2 3/0 91/34 (37.4%)
Total WRC results
Races/wins 1 8 8/1 7 5 4 3 2 38/1
Entries/finishes 3/0 28/14 38/18 22/9 9/3 4/0 4/2 3/1 111/47 (42.3%)
Total points 53 63 13 5 1 135
(3.648 per race)
(1.216 per entry)

Races

Works team: Ford Motor Co

Season

Homologated as group B prototype
Entry Rally event
Driver
Codriver
Team MC SVE
Entry list
POR KEN TdC GRE NZ ARG FIN (CdI) SR RAC (Oly)
Phil Collins
Bryan Thomas
F.D. suspe nsion
Rob Stoneman
Peter Davis
F.D. diffe rential
Chris Mellors
Brian Staker
Securicor Team Go-Phone diffe rential
Statistics
Starts/finishes 3/0 3/0

Information and articles

Article from 4T 208, 1/1988

Click here

DSCF0592.jpg Source
gpa0001.jpg Source
beam2.jpg Source
despiece-ford-sierra_1.jpg Source

Drawings

Ford-Sierra-RS-Cosworth-1986-1988-Photo-02-800x600.jpg Source
ford_sierra_rs500_1987.jpg Source

Engine

cosworth2litros.jpg Source

Borg Warner T5 gearbox

T5_89_1.jpg Source
T5_0.jpg Source

Suspension

C1.25.gif Source
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