Toyota
Celica GT-Four ST-205 History
Toyota’s
last rally-Celica, the GT-Four (ST-205) appears in the later
half of 1994, featuring a new shape body and five special characteristics:
better aerodynamics, improved front suspension, 16-inch wheels
as standard, a stiffer chassis with more longitudinal members
and water injection for the engine.
The most striking
feature about the improved aerodynamics is the high mounted
wing which allows more downforce at the rear. Often the engine
cooling is more difficult if the drag coefficient is reduced
but the engineers were quite happy with the air inlet openings
in the front of the car, resulting in the same cooling efficiency
as with the ST-185.
To allow
air to escape, slightly bigger openings have been cut in the
bonnet and there is more space between the water radiator and
the engine block. To do this the radiator has been brought further
forward which allows for better airflow inside the engine.
The
purpose of the wing is to help compensate the inherent disadvantage
of weight balance. The aerofoil has been designed to minimise
drag losses while increasing the down-force and it is effective
from 100-120 kph upwards.
Better traction
makes the car more stable. The amount of down-force is influenced
by the right height but wind tunnel tests proved a downforce
of 50 kg at 100kph with the wing in its high position.
The
pickup point for the suspension arms are different and instead
of mounting them directly to the bodyshell there is now an additional
sub-frame which is part of the new design of the chassis.
The Toyota Celica GT-Four (ST-205) now has 16-inch wheels as
standard. There are two reasons for this: it allows for bigger
brakes in Group N, which is very important and it means that,
in Group A-spec, the car can go to 18-inch wheels for tarmac
events.
After an extensive test programme the Toyota Celica GT-Four
made its World Championship debut in the second half of the
1994 season.
The Toyota team was promised success up to the Catalunya rally
in 1995 when an FIA commissioner discovered a weird device in
Didier Auriol's Celica ST205.
To limit the horsepower in rally cars the FIA
had regulated the use of a turbo restrictor. This is a device,
resembling a tube, with regulations specifying that the dimensions
fit it in the turbocharger's air intake to limit the air flow
and consequently the engine's output.
Toyota
engineers had mounted the restrictor in a way that it would
slightly move from its original position, allowing more air
into the turbocharger, when the car was running.
This of course was prohibited and as a consequence Toyota was
excluded from the World Rally Championship. Too bad for their
drivers; Juha Kankkunen, Didier Auriol and Armin Schwarz at
the time, who declared they knew nothing whatsoever about the
presence of such a device in their cars.
No one ever found out whether the device came from Toyota Japan
or from Toyota Team Europe. Either way each party must have
known about its presence.
Within the factory team, this successful car
was replaced by the Toyota Corolla WRC in the latter half of
1997, but will still run as a serious contender in various championships
by private teams all over the world, and for many years to come.
