The Sprint chassis' excellent dynamic balance motivated engineers in Italy and other continents to create
ultra-high-performance versions, completely reconfiguring the model's mechanical architecture:
The Autodelta Sprint 6C Prototype (1982)
Designed by Autodelta, Alfa Romeo's official racing and tuning division under the command of engineer Carlo
Chiti, with the goal of homologating the car in the FIA Group B rally category. For this, the front end was
stripped: the Boxer engine and front-wheel drive were removed. In place of the rear seats, the 158 hp 2.5 V6
Busso engine (inherited from the GTV6) was installed longitudinally, coupled to a ZF five-speed transaxle
that sent power to the rear wheels.
Only two prototypes were built. The first featured a more civilized finish in grey leather and red carpet,
while the second was track-focused, with acrylic windows and a modified engine cover with integrated air
vents. Currently, the second prototype rests in the historical collection of the Arese Museum in Italy,
while the first was located in South Africa after years of being missing.
The Australian Giocattolo Group B (1986–1989)
Inspired by the Italian 6C prototype, Australian businessman Paul Halstead and Formula 1 designer Barry Lock
(ex-McLaren) created a mid-engine supercar. Initially, the project planned to use Alfa Romeo V6 engines
mounted in the Sprint's rear. However, due to high import costs and the Italian manufacturer's refusal to
supply official components directly, Halstead changed the plan.
The V6 engine was replaced by the powerful 5.0-liter Holden Walkinshaw Group A V8 engine manufactured by the
HSV sports division, generating 255 hp (190 kW) and coupled to a ZF transmission. Engineer Barry Lock
designed an independent rear suspension with overlapping wishbones coupled to a lightweight aluminum
structure. With doors and lids made of Kevlar, the car weighed only 1,084 kg (2,390 lbs) and accelerated
from 0 to 100 km/h in the 4.5-second range, outperforming contemporary rivals like the Ferrari 348.
Only 15 cars were built at the Caloundra factory, Queensland, with 14 original examples surviving today. As a
folkloric detail, the car's official tool kit contained a bottle of traditional Australian Bundaberg rum
accompanied by two glasses to "comfort" the owner in case of a roadside mechanical breakdown.