Alfa Romeo Alfasud Sprint 6C – Group B Prototype

Published on: Jan 18, 2016 @ 15:43
Originally Published in: 2015 (old website)
(C) Jay Auger - website owner & author
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INTRODUCTION

In 1980, the FISA officially approved the new Group B category to begin two years later in 1982. Many manufacturers were thus enticed by the lower homologation demands and lax rules of the new class due to replace Group 4 in the World Rally Championship and other racing series. Alfa Romeo’s first bid for a Group B car was with the Alfasud Sprint 6C. The project timetable set for it to be ready to compete for the 1983 season – it sadly never made it that far.


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HISTORY

Alfa Romeo Alfasud Sprint – a stylish redesign by Autodelta

Compared to the production version, the Sprint 6C Group B prototype sported new front and rear sections, wider fender flares, louvres and a lip spoiler. Two prototypes are rumoured to have been built for possible homologation; one more inclined towards the specifications of a road car and the other a bit more evolved towards racing.

What is most special about the Sprint 6C is that the Alfa Romeo engineers installed the drivetrain from the GTV6 behind the front seats, quite similarly to Renault’s “quick recipe for success”: the R5 Turbo – a car that converted front-engine and front-wheel drive to a mid-engine and rear-wheel drive layout. The GTV6 engine had already proven itself in the European Touring Car series, developing around 220 BHP, so it was the logical choice to power the new prototype rally car.

In 1982, the “first” 6C Group B prototype was presented to the automotive press at the famous Italian Monza Circuit and subsequently to the general public at the year’s Paris Auto Show. Rumour has it that this prototype was not functional and for publicity purposes only – which is substantiated by the odometer that still sat at zero at the time of its reveal.

The “two” prototypes can be differentiated from one another in the following ways; the “road car” prototype has a black grille, two small round door mirrors, black rear screen louvres, a spoiler with “Sprint 6C” decals, and a large oval centre exhaust pipe, while the “racing” prototype has a chromed centre grille, auxiliary lamps fitted underneath the front bumper, one large squared door mirror (driver side only), moulded body-coloured rear screen louvres, a spoiler with an Alfa Romeo badge also featuring cooling intakes (for an oil cooler and engine cold air intake), different license plate position with a meshed vent (for the oil cooler), recessed tail lights, a redesigned rear bumper cover with auxiliary stop lamps and twin exhaust pipes.

Both versions featured a “thermo-acoustic” glass partition between the cabin and rear engine bay. The open louvres on both models effectively replaced the rear screen and provided much needed venting for the engine bay. The interior of the “racing” prototype, although quite complete, was barer and featured racing seats and harnesses – which made it more suited to be a true competition model.

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The “racing” prototype was said to be fully functional although it remained in an early unrefined test bed form, suggesting that it was quickly put together as a proof of concept. The mid-mounted engine and longitudinal rear transaxle can clearly be seen, including an all new rear suspension setup that included a period rally-style twin damper setup paired with dual wishbones.

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Although the potent V6 engines of the touring cars were of 2480 cc, Alfa had planned to homologate the 6C with a revised displacement of 2503 cc, in theory putting it in the 2500~2999 cc Group B class regulations instead. This might seem like a bad move at first but it was actually quite cunning as the 6C weighed-in at 990 kg (2,180 lbs) and better matched the 960 kg (2,115 lbs) minimum weight of that particular class. The higher engine class would allow the use of wider tires and the possibility for the “evolution” engines (that would power the rally cars) to be increased up to 2999 cc in displacement for extra power and torque outputs.

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Theoretically, the homologation 2.5 litres “road car” engines would have a rating of around 160 BHP but the “evolution” 3.0 litres engines were planned to produce anywhere between 240 and 300 BHP, both versions normally aspirated – the latter improving on the output of the touring cars. It is most likely that the prototype(s), in such an early stage of development, featured the normal production 2492 cc GTV6 engine rather than the planned homologation 2503 cc unit.

However, for reasons publicly unknown to this day, the Alfa Romeo board of directors decided not to go forward with the Sprint 6C project and settled with the existing 1980 Group 4 Alfetta GTV Turbodelta for Group B homologation instead. It must be noted that Alfa Romeo was undergoing financial troubles at the time and conversion costs for the required 200 homologation cars might have been too much. Sadly, even though all agree that the Sprint 6C could have been the “Italian R5 Turbo” and be a commercial success, the cancellation of the project robbed the world from a spectacular machine that would have sat very well parked alongside a Lancia 037 Stradale in the Tuscany countryside.

Insiders disagree if one, two or even more cars were built since the first “road car” prototype shown at Monza could have been upgraded to the second “racing” prototype, and more possibly for crash tests, but proof has yet to be presented for either argument.


SPECIFICATIONS

Group/Class B/12 PROTOTYPE
Year of conception 1982  # built: 1 or 2
Engine
Type GTV6, V6, SOHC 12v, gas mid-mounted, longitudinal, 60° V6
Displacement 2492 cc planned for homologation: 2503 cc
Compression ratio
  • road: 9.0:1
  • racing: N/A
Output power – torque
  • road: 158 BHP @ 5600 RPM
  • racing: 300 BHP @ – RPM (suggested)
  • road: 157 lb-ft @ 4000 RPM
  • racing: N/A
Materials block: light alloy cylinder head: light alloy
Aspiration
  • normal / natural
  • Bosch L-Jetronic fuel injection
Ignition
Cooling system water-cooled
Lubrication system wet sump rear-mounted oil cooler (racing prototype)
Transmission
Type rear-wheel drive 5-speed manual
Gearbox ratios
Differential ratios ZF type, longitudinal transaxle
Clutch
Chassis-body
Type based on “Sprint” model: steel monocoque chassis, 3 door hatchback, steel bodyshell with polyester bonnet, rear hatch,  louvres and bumper covers
Front suspension independent, double-wishbone, coil-over hydraulic damper
Rear suspension independent, double-wishbone, dual coil-over hydraulic dampers
Steering system
Brakes front & rear: vented discs
Dimensions
length: 4024 mm (158.4 in) width: – mm (- in) height: – mm (- in)
wheelbase: 2455 mm (96.7 in) front track: – mm (- in) rear track: – mm (- in)
Rims – tires Speedline 15 inch
  • Pirelli P700
  • Front: 205/50VR15
  • Rear: 225/50VR15
Dry/Unladen Weight 990 kg (2180 lb)
Weight/power
Fuel tank

VIDEOS


GIOCATTOLO MOTORI “GROUP B”

Giocattolo Group B
Giocattolo “Group B”

In 1986, years after the Sprint 6C project cancellation by Alfa Romeo, it was spiritually revived by Barry Lock of Giocattolo Motori – a short-lived auto company out of Australia. The company purchased a few Sprint cars from Alfa to recreate a custom version of the original mid-engine 6C prototype. However, the GTV6 engines were very expensive to import and, after the third car built, they were replaced by the Holden 5.0L V8s which were cheaper and locally available. The resulting car was simply named the “Group B”. Fifteen cars were built until the company folded just three years later in 1989.


REFERENCES

(C) Article by Jay Auger – website owner, main author & chief editor

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