The performance of the Alfa Romeo 155 in sports tournaments gave rise to rare street versions that
today are coveted by collectors worldwide.
The Controversial Silverstone / Formula Version
Launched in 1994, the Silverstone edition (called Formula in some continental markets) had 2,500
units produced to meet the criteria required by the British Touring Car Championship (BTCC). Equipped with
the 129 hp 1.8 Twin Spark engine, the great differentiator of this car was its adjustable aerodynamic
package, consisting of an extendable front spoiler and a rear wing that could be mounted in a raised
position.
The controversy lay in the fact that the manufacturer sold the car with the wings retracted and
supplied the elevation brackets disassembled in a black wooden box stored inside the trunk. On the track,
the official racing team initially raced with the wings fully extended, which generated a strong protest
from opposing brands like Ford and Vauxhall. Ford even acquired a street-legal 155 Silverstone to prove that
the average customer would not drive the car with the rear wing raised using 31 fixing rivets, which would
be illegal.
The conflict resulted in the temporary disqualification of the points obtained by Alfa Romeo in the
Snetterton and Silverstone races. Before the Oulton Park round, the federation stewards ordered the team to
race with the wings lowered. In immediate protest, the official team withdrew its cars from the track and
left the circuit.
A subsequent agreement determined that the 155 could race with the wing raised only until July 1,
1994, and had to retract it in the following rounds. Even so, driver Gabriele Tarquini secured that year's
drivers' title in an imposing manner.
That year's track version hid sophisticated mechanical secrets. Although it used the Fiat group
engine block, the cylinder head was derived from the 155 Q4 turbo, but rotated 180 degrees to optimize
cooling flow and lower the engine's center of gravity. Additionally, the car featured an innovative front
differential with mixed hydraulic and mechanical actuation, a technology that was later copied by opposing
teams. Due to all this homologation controversy, the BTCC rules changed radically for the 1995 season,
raising the minimum of cars sold to 25,000 units and making the use of standardized aerodynamic wings
mandatory for all competitors.
The Exclusive 155 GTA Stradale
Created in 1992, the GTA Stradale was designed by Abarth under the leadership of engineer Sergio
Limone to celebrate Alfa Romeo's victories in the Italian Superturismo Championship. Built on the mechanical
base of the 155 Q4, the car featured permanent all-wheel drive and the 2.0-liter turbo engine prepared with
Group N rally specifications.
To shift the car's weight further back and improve rear axle grip, Limone used a rear differential
housing made of cast iron instead of aluminum. The suspension was identical to that of the Lancia Delta
Integrale, and the exterior received a kit with widely flared fenders and sporty bumpers.
Only one prototype unit (chassis ZAR16700000005892) was completed before the Fiat board decided to
cancel the project. Executives demanded that the car use a V6 engine, which did not physically fit in the
engine bay alongside the Delta Integrale's all-wheel drive, and they also considered the cost of assembly on
a parallel production line financially unviable. The unique prototype served as a medical car at the 1994
Formula 1 Monza Grand Prix, transporting the official FIA doctor, Dr. Sid Watkins.
The Zagato Special Editions: TI.Z and GTAZ
Developed by the famous Italian coachbuilder Zagato, the TI.Z (launched in 1993) and GTAZ (launched
in 1995) models emerged from a specific demand from enthusiasts and investors in the Japanese market. Faced
with the Alfa Romeo board's refusal to produce a more aggressive version of the 155 for cost reasons, this
group of importers struck a direct agreement with Zagato.
The models had an exclusive muscular bodywork and special alloy wheels supplied by the OZ brand. The
TI.Z model utilized the 2.0 Twin Spark engine tuned to generate 170 hp. The top-of-the-line model, GTAZ,
used the Q4's turbo engine and all-wheel drive recalibrated to deliver 215 hp at 5,500 rpm and 314 Nm of
torque at 2,500 rpm. Weighing 1,400 kg, the GTAZ accelerated to a top speed of 230 km/h. Almost all of the
very few produced units of these models were exported exclusively to the Japanese market.