RX MG Metro 6R4 – Will Gollop

gollop6r45
MG METRO 6R4 RX (Will Gollop)

Since it was one of the cheapest Group B cars to purchase, the MG Metro 6R4 turned out to be very popular in rallycross, even more so in the British Championship. While it didn’t have forced induction, the high output normally aspirated engine was considered to be advantageous for rallycross since it didn’t have turbo lag.

In 1987, Will Gollop began competing with a 6R4 in the European Rallycross Championship. As it was common with other Group B competitors, his car sported a few “lesser” parts coming from the homologation model; mainly the brakes and suspension. Smaller brakes were preferred in rallycross to reduce unsprung weight which helped acceleration and traction. While the WRC car had about 380 HP, Gollop’s 6R4 was tuned to produce around 420 HP. While the power output was lower than the turbocharged competition, the 6R4’s better engine response and diminutive size could make up for it. However, the high horsepower war of over-boosted turbo engines soon took over rallycross with figures ranging from 600 to 900 HP.

By then, Gollop made the choice to turbocharge his 6R4 to remain competitive, but a rule change by the FISA would make this a harder proposition:

In 1989, since it was obvious that the FISA couldn’t control the power output of turbocharged engines, they augmented the multiplication factor from 1.4 to 1.7 which meant that most cars now had to carry extra weight.

However, some competitors, including Will Gollop, got creative to circumvent the new rule and de-stroked their engines to keep the horsepower / low weight combination they had beforehand. The smaller displacement engines revved higher but produced a bit less torque.

Gollop’s 6R4 3.0L engine was reduced to 2.3L and twin turbocharged. It could redline at 11,000 rpm and was rumored to be able to produce up to 800 HP. However, for reliability and heat management purposes, the power was kept around 650 HP. To handle the extra power, the 6R4’s drivetrain was beefed up with upgraded differentials and Xtrac transmission components in the stock casing. It turned out to be a successful combination and Gollop, albeit short of winning the championship early on, consistently achieved podium finishes.

At the 1991 race in Lydden Hill England, Gollop suffered a devastating crash while attempting a pass during a heated battle with Martin Schanche and Pat Doran. The event basically handed the championship over to Martin Schanche, who was trailing Gollop in the points coming into the last event where Gollop could not compete. The car was painstakingly rebuilt for the 1992 season even though it was to be the last year of competition for Group B cars. An effort which recompensed Gollop in full by winning the 1992 European championship.

SPECIFICATIONS

N = Normally Aspirated version / T = Turbocharged version

Group/Class Formula A / Division 2 Championships: 1 (1992)
Years active 1987~1992
Engine
Type “V64V”, V6, DOHC 24v, gas located middle longitudinal
Displacement
  • N: 2991 cc
  • T: 2.3L
Compression ratio
  • N: 12.0:1
  • T: N/A
Output power – torque
  • N: 420 HP @ 9,000 rpm
  • T: 650 HP @ – rpm
  • N: 246 lb-ft @ 6,500 rpm
  • T: – lb-ft @ – rpm
Materials block: aluminium alloy cylinder head: aluminium alloy
Aspiration N

  • Natural/ Normal
  • Lucas-Micos multipoint EFI

T

  • Twin KKK turbochargers
  • Twin air/air intercoolers
  • Boost: 19~22 psi
  • Modified Lucas-Micos multipoint EFI
Ignition Lucas-Micos electronic
Cooling system water-cooled
Lubrication system dry sump
Transmission
Type four wheel drive
  • N: 5 speed gearbox
  • T: same but with Xtrac gears
Gearbox ratios 1st: 2.938
2nd: 2.263
3rd: 1.696
4th: 1.300
5th: 1.091
Differential ratio
  • N: 3.90
  • T: 3.41
helical gears ferguson viscous coupling epicyclical center differential, 1st output to hypoid spiral bevel gears limited slip rear differential located in engine sump, 2nd output to hypoid spiral bevel gears limited slip front differential. 45-55% front to rear torque distribution
Clutch AP twin plate
Chassis-body
Type Two main longitudinal chassis members, integral roll cage and spaceframe. 2 door hatchback fiberglass bodyshell. Aluminium roof panels. Steel doors with Kevlar reinforced air ducts. Rear Spoiler. Front spoiler removed.
Front suspension MacPherson strut with lower wishbone, coil spring, telescopic Bilstein gas shock absorber. Anti-roll bar removed.
Rear suspension MacPherson strut with parallelogram wishbone and trailing arm, coil spring, telescopic Bilstein gas shock absorber and anti-roll bar.
Steering system rack and pinion 2.5 turns lock to lock
Brakes “Clubman” front and rear ventilated disks and calipers dual circuit with servo, adjustable ratio split front to rear
Dimensions
length: 3657 mm (144.0 in) width: 1880 mm (74.0 in) height: 1500 mm (59.1 in)
wheelbase: 2412 mm (95.0 in) front track: 1510 mm (59.4 in) rear track: 1550 mm (61.0 in)
Rims – tires 15 or 16 inch Avon
Dry/Unladen Weight 960 kg (2115 lb)  Bias F/R: 45-55%
Weight/power
  • N: 2.3 kg/HP (5.0 lb/HP)
  • T: 1.5 kg/HP (3.3 lb/HP)
Fuel tank 25 liters

PICTURES & VIDEOS

gollop6r4

gollop6r41

gollop6r43

gollop6r44

gollop6r46


Article by Jay Auger

Website owner & author


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