Ford Sierra Sapphire RS Cosworth 4x4 group A (1990)
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Home » Rally Cars » Ford Sierra Sapphire RS Cosworth 4x4
Ford_Sierra_RS_Cosworth_registered_August_1989_1993cc_in_profile.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

In rallies: see video
On board: see video with Malcom Wilson in RAC '90

Specifications

Group/Class A/8 Homologation number: A 5414
Years active 1990 - 1992 Homologation start: 1/8/1990
Homologation end: 31/12/1999
Engine
Type Cosworth YBJ based on Pinto block, straight 4cyl, 4 stroke, petrol engine located front longitudinal
Capacity 1994.4 cc WRC: x 1.7 = 3390.4 cc
Bore x Stroke (mm) 90.8 x 77.0
Compression ratio 7.2:1
Output power - torgue 300 (330) HP / 6500 rpm 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, 220mm height cylinderhead: aluminium alloy, 138mm height
Cams/valves 2 overhead camshaft (DOHC), belt driven. Red cam cover (non catalyst), green cam cover (catalyst) 4 valves/cyl. - 16 valves total. 35.25mm inlet valve diameter, 31.25mm exhaust valve diameter. 1 coil springs per valve
Aspiration Garrett TB03 turbocharger (inconel turbine 59mm diameter, aluminium compressor 60.3mm diameter) with air/air intercooler and 40mm turbo restrictor fitted, Bosch L-jetronic multipoint electronic fuel injection.
1992-1994: 38mm turbo restrictor fitted.
1995+: 34mm turbo restrictor fitted.
pressure: 1.6 bar
Ignition electronic, firing order 1-3-4-2
Cooling system watercooled 8.2 lt
Lubricating system wet sump with 1 oil cooler 3.8 lt
Transmission
Type four wheel drive MT75 5 speed, or MS90 7 speed gearbox
Gearbox ratios constant: 1.320/1 (33/25)
1st: 3.608/1 (41/15)
2nd: 2.082/1 (41/26)
3rd: 1.363/1 (32/31)
4th: 1.000/1 (-)
5th: 0.828/1 (27/43)
R: 3.256/1 (37/15)
MT75, constant input: 1.091/1 (24/22)
1st: 2.649/1 (34/14)
2nd: 1.909/1 (28/16)
3rd: 1.515/1 (25/18)
4th: 1.227/1 (27/24)
5th: 1.000/1 (-)
R: 2.961/1 (38/14)
MS90/1, Low: 2.071/1 (29/14)
1st: 1.529/1 (26/17)
2nd: 1.263/1 (24/19)
3rd: 1.037/1 (27/28)
4th: 0.866/1 (26/30)
5th: 0.750/1 (32/24)
6th: 0.647/1 (24/32)
R: 2.143/1 (30/14)
MS90/2, Low: 2.071/1 (29/14)
1st: 1.529/1 (26/17)
2nd: 1.200/1 (24/20)
3rd: 0.955/1 (21/22)
4th: 0.792/1 (19/24)
5th: 0.654/1 (17/26)
6th: 0.536/1 (15/28)
R: 2.143/1 (30/14)
Diffrential ratio Transfer box: 1.000/1 (31/31), 1.800/1 (36/20), 1.714/1 (36/21), 1.619/1 (34/21), 1.545/1 (34/22), 1.478/1 (34/23).
for MT75: 1.000/1 (31/31), 1.417/1 (34/24), 1.231/1 (32/26).
1991+: 1.833/1 (33/18), 1.800/1 (27/15), 1.737/1 (33/19), 1.667/1 (25/15), 1.600/1 (32/20), 1.550/1 (31/20), 1.476/1 (31/21), 1.688/1 (27/16), 1.625/1 (26/16), 1.471/1 (25/17), 1.429/1 (30/21), 1.391/1 (32/23), 1.333/1 (32/24), 1.333/1 (24/18), 1.318/1 (29/22)
1991+ (for MS90/2): 1.529/1 (26/17)
Front/rear: 3.615/1 (47/13), 2.917/1 (35/12), 3.133/1 (47/15), 3.357/1 (47/14), 3.846/1 (50/13), 4.077/1 (53/13), 4.636/1 (51/11). 1991+: 4.375/1 (35/8), 4.429/1 (31/7)
Front: 3.917/1 (47/12), 3.615/1 (47/13).
Heavy duty, 4.444/1 (40/9), 3.636/1 (40/11), 3.250/1 (39/12).
Rear: 7" or 7.5", 5.111/1 (46/9), 4.889/1 (44/9), 4.667/1 (42/9), 4.571/1 (32/7), 4.444/1 (40/9), 4.429/1 (31/7), 4.273/1 (47/11), 4.125/1 (33/8), 4.091/1 (45/11), 3.857/1 (27/7), 3.818/1 (42/11), 3.636/1 (40/11), 3.625/1 (29/8), 3.375/1 (27/8), 3.143/1 (22/7).
9", 3.417/1 (41/12), 3.250/1 (39/12), 3.083/1 (37/12)
helical gears input epicyclical center differential with viscous coupling connected to transfer box, with 2 outputs: 1st direct output to hypoid bevel gears, ZF limited slip or Torsen rear differential. 2nd output via hyvo chain in parallel shaft to hypoid bevel gear limited slip front differential. 34%-66% front/rear torque distribution (From Sierra XR4x4)
Clutch dry, single disk 242mm diameter
Chassis-body
Type Steel monocoque chassis with roll-cage. Front steel subframe. 4 door saloon steel bodyshell
Front suspension macpherson strut with lower wishbone, coil springs, telescopic gas shock absorbers and 30mm diameter anti-roll bar
Rear suspension semi-trailing arm with coil springs, telescopic gas shock absorbers and 18mm diameter anti-roll bar
Steering system rack and pinion with hydraulic power assistance 2.4 turns lock to lock
Brakes ventilated front disks with 278mm disk diameter and 1 cast iron piston caliper, or 280/285/304/315/355/340/345 disk diameter and 4 aluminium piston calipers. Ventilated rear disks with 273mm disk diameter and 1 cast iron piston caliper, or 280/285/304/315/355/340/345 disk diameter and 4 aluminium piston calipers ratio slit front to rear
Dimensions
length: 4.49 m (177.1") width: 1.698 m (66.9") height: 1.369 m (55.0")
wheelbase: 2.625 m (103.3") front track: 1.464 m (57.6") rear track: 1.480 m (58.3")
Rims - tires gravel 7" - 8" x 15" - 16", tarmac: 8" - 9" x 16" - 17" michelin
Weight 1150 kg
Weight/power 3.5 kg/HP
Fuel tank 75 lt
Drag coefficient 0.33

Results in WRC

Statistics

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 Total
Works
Races 3 8 8 19
Entries/finishes 9/2 20/10 16/12 45/24 (53.3%)
Others
Races +2 +3 4 4 3 3 2 2 2 25
Entries/finishes 8/5 28/11 30/15 16/8 15/7 9/6 9/4 3/0 5/4 2/0 125/60 (48%)
Total WRC results
Races 3 10 11 4 4 3 3 2 2 2 44
Entries/finishes 17/7 48/21 46/27 16/8 15/7 9/6 9/4 3/0 5/4 2/0 170/84 (49.4%)
Total points 7 66 83 4 160
(3.636 per race)
(0.941 per entry)

Races

Works team: Ford Motor Co

Season
Entry Rally event
Driver
Codriver
Team M.C
Entry list
POR KEN TdC GRE (N.Z) ARG FIN AUS S.R (CdI) RAC
Pentti Airikkala
Ronan McNamee
Q8 Team Ford gear box 11th acci dent
Malcolm Wilson
Nicky Grist
Q8 Team Ford with drawn acci dent cam belt
Franco Cunico
Stefano Evangelisti
Q8 Team Ford acci dent throttle cable
Alex Fiorio
Luigi Pirollo
Q8 Team Ford 9th
Marc Duez
Alain Lopès
Ford Fina Rally Team 14th eng ine
Colin McRae
Derek Ringer
Shell UK Oil 6th
Jimmy McRae
David Senior
Shell UK Oil acci dent
Brian Bell
John Robinson
22th
Russell Brookes
Neil Wilson
Rally Engineering Development 36th
Jonathan Joannides
Walter Goltz
43th
Dave Holland
Stephen Griffiths
axle
Total points
()
7 7
Statistics
Works starts/finishes 9/2 3/0 3/1 3/1
Others starts/finishes 8/5 1/1 7/4

Information and articles

Article form 4T 260, 5/1992

Click here

Article from 4T 257, 2/1992

Click here

Article ftom Auto Express 275, 6/1990

Click here

m9CccyyqEuIX2YXTvIZQYUg.jpg Source
Rear 7.5" differential

Drawings

ford_sierra_sapphire_cosworth_4x4-25280.jpg Source
q8oilsfordsierrasapphir.jpg
1990fordsierra4x4coswor.jpg Source

Transmission

ford-sierra_xx.jpg Source
ford-sierra-4x4-differential.jpg Source
ford-sierra.jpg Source

Front differential

Ford-Sierra-Front-Diff-Diagram.gif Source
Front differential 3.917/1 (47/12)

MT75 gearbox

mt75.GIF Source
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