Geartronics - digital sequential gear indicators for sequential gearboxes from Hewland, Quaife, Gemini, X-trac, Glebe & Sadev.
digital gear indicators for sequential gearboxes sequential gear indicators for Hewland, Quaife, Gemini, X-trac, Glebe & Sadev and other motorsport transmissions rally gearboxes and race gearboxes
digital gear indicators for sequential gearboxes sequential gear indicators for Hewland, Quaife, Gemini, X-trac, Glebe & Sadev and other motorsport transmissions rally gearboxes and race gearboxes
Rallycar
The car was originally built by Geartronics
director, Neil Wallace, back in 1988. Starting
life originally as a Talbot Sunbeam 1.6GL, now
the only parts that have remained standard are
the light units and a few bits of trim!

The first rally outing for the car and driver was
the 1989 "Carrac Bevmag stages" at Manby
airfield in Lincolnshire. Incidentally, the event
was won by a certain Johnny Milner driving a
Peugeot 205 in what was his first rally event!

For the first few years of competition the car
remained fairly low-tech, sticking to the
modifications that the 'works' teams used in the
early eighties. This kept the car ultra reliable if a
little slow and uncompetetive. The original
pushrod 1600cc engine was retained and at the
hight of development managed a realistic
130bhp at best.
rollcage
The picture on the left shows the rollcage installation. After a serious
accident in 2000 in which the crew were lucky to escape uninjured, it
was decided to install a 'proper' rollcage along the lines of the latest
WRC cars. While not using the exotic and prohibitively expensive
materials of the works teams, the rollcage is welded into the bodyshell
at numerous points and includes triangulation members to substantially
increase the rigidity of the 'shell. If you would like a cage of this quality
you could do a lot worse than to contact Richard Lepley at
Click pictures to enlarge
engine assembly
Like all aspects of Geartronics work, the preparation of the engine is done to the very
highest standards. When assembling a high performance race engine it is critically
important to maintain almost clinical cleanliness. The slightest spec of dirt can in
some cases lead to reduced engine life or in extreme cases, catastrophic engine
failure! The engine fitted to the Geartronics car is based on the Vauxhall 2 litre 'XE' 16
valve. However, whereas the standard engine produces in the region of 150bhp @
6000rpm the race engine produces around 230bhp at some 7500rpm and can safely
rev to 9000 - a speed at which the standard engine could never reach under its own
steam and would probably disintegrate if it could!

To achieve power outputs of this level requires a great deal of modification to both the
internal & external components of the engine. Forget bolting on a fancy air filter and a
'big bore' exhaust, this will do practically nothing to increase performance but plenty to
annoy other motorists! Forget also the highly dubious figures from some tuners who
claim in excess of 200bhp just by fitting fuel injection throttle bodies to an otherwise
standard engine. To produce much in excess of 200bhp requires engine speeds to
increase well beyond the 6000rpm of the standard engine and to do this the standard
camshafts will certainly not do. Because of the increased engine speeds required to
produce the higher power, special pistons, crankshaft, connecting rods, flywheel etc
have to be used to cope with the dramatically increased stresses that come with this
higher speed.
Vauxhall 20XE engine
Engine bay
Inside rallycar
The photograph on the left shows a view of the
passenger compartment, obviously. As can be
seen, it is far removed from an everyday road
car. Anything that is not required is removed to
save weight and there are numerous safety
features installed, most notably the internal
rollcage, seats and 3" wide 6 point harnesses.
Other safety items visible in the picture are the
fire extinguisher in the passenger footwell and
the battery isolation switch in front of the gear
lever. There is also another fire extinguisher
behind the seats which is plumbed into the
passenger compartment and engine bay, this
can be triggered by either of the crew or
externally by marshall's in the event of an
accident.
front suspension
Just as important as making the car fast, it is vital that
the car is able to corner and stop effectively. To this end,
special brake and suspension components must be
used. The Geartronics car uses many unique and
purpose designed suspension components in an effort
to maintain optimum suspension geometry at all times.
All the rubber suspension joints of the standard car are
replaced by spherical bearings and existing balljoints
are replaced with larger & stronger items. The braking
system uses discs all round which are considerably
larger than standard, the ventilated fronts are gripped by
large 4 piston aluminium calipers which help dissipate
the heat generated by sustained heavy braking.
Quaife 6 speed gearbox
Rear axle
gearbox internals
The transmission system of the Geartronics
Sunbeam is pretty conventional but utilises
some fairly high tech components, most
notably the 6 speed sequential gearbox.
Engine power is transmitted to the gearbox via
a 'lug drive' twin plate ceremetallic clutch. Drive
from the gearbox is then taken by a single
piece propshaft to the live rear axle. The axle
is '5 linked', in other words there are 4 fore &
aft links and a transverse panhard rod for
lateral location. Now here comes the trick part
of the system because the gearbox is
interfaced to The Geartronics control ECU.
A sensor on the gearstick detects an imminent
Gear change. On receiving this signal, the Geartronics Flatshift ECU momentarily turns off the engine, thus
removing power from the gears. Because the gearbox uses dog engagement instead of syncromesh,
extremely rapid up-shifts can be made without use of the clutch or lifting off the throttle! This maximises
power delivery to the road and helps keep the car balanced due to the fact that power is only lost
momentarily - it also sounds superb!