G-Force System by the Auto Edge
2000 June: Since the start of the year,
Joe Beninca and Bert van Dijk of
the Auto Edge have been
putting a new twist on a four wheel drivers' holy grail -
The aim is to provide a vehicle with, at one and the same time,
stiff suspension to resist roll for good on-road cornering
and also soft suspension to
allow good axle articulation and grip off-road.
The G-Force anti body roll control suspension system
is a development of an idea
of Erica inventor Phill Di Maria
which first saw light of day in the 1980s.
That idea is to sense cornering accelerations and apply
forces via an engine driven pump and a hydraulic ram acting on a link
between the left and right sides of the vehicle so as to resist roll.
The original Mk-0 system used a pendulum
together with electronic control.
About 50 Mk-0's were fitted to vehicles.
Following Henry Ford's dictum of adding simplicity,
the new Mk-1 G-Force system is entirely mechanical - hydraulic.
A pendulum valve (above) controls double acting rams
that act on links resembling roll-bars front (left) and rear.
Pressure comes from an engine driven pump (below).|
Left: The patented valve in each double acting ram,
can apply a pressure in either direction yet still react
to shock loads like a shock absorber.
Each ram has three hydraulic lines into it - one for up, one for down,
and a control line through the ram itself to the valve.|
Left, below: Checking the valving on a shocker dyno'.
The Auto Edge reports that for au$4K
most popular four wheel drives can be fitted with the system,
e.g. Range Rover,
Land Rover Discovery,
Nissan Patrols post ~1990, and
Toyota LandCruiser 60, 75, 80 and 100 series.
About 100 Mk-1 G-Force systems are on the road as of mid 2000.|
Above: Kit for a Range Rover,
less the rams and roll bars.
Does it work? Yes it does.
A quick spin around the block in a Toyota 100 series
fitted with a Mk-1 G-Force system showed that on-road it handled
well with very little body roll.
The demonstration vehicle has a non-standard switch to disable the system,
in which case more cornering lean becomes evident.
Off-road in four wheel drive, it should perform as well
as a 4WD with a very flexible suspension because the system
is only trying to keep the car level, not trying to keep the axles
parallel with each other.
You would expect one group of prospective buyers to be those
who want good on-road handling and also good axle
articulation off-road and, for example, some four wheel drive racers
Another likely group consists of operators of
tall, heavy vehicles and the army, ambulance services and
Brits 4WD campers are said to have tested units.
For the future, the Auto Edge is developing a Mk-2 system
which dispenses with the mechanical link across the vehicle:
Four rams are used, one at each corner of the vehicle,
the link from left to right becoming purely hydraulic.
In this case, the rams are integrated into shock absorber units and
MacPherson struts, doing double duty.
This is somewhat more complex than Mk-1, but tidier and more compact.
A further advantage is that because the oil is being circulated
by the pump, it stays cool so overheating and shock absorber
failure are much less likely.
You would need about au$12K for a Mk-2 system just now.
And you might see one in a 4x2 soon, perhaps a Commodore, or
even a Porsche, because if you are wondering where you have
heard the name Beninca, he pushes Porsches around race tracks,
very quickly, at weekends.
- © L. A11ison,
The Auto Edge,
581 Canterbury Road, Surrey Hills,
Rangie Spares (Andrew Richmond 9464-4094),
SafeTrek 4WD services (Jim Kennedy 9386-7077),
4WD Connections & Turbo Eng. (Caroline Miller 9439-6122),
C.G.A. (Graham Stuckey 9720-3338),
Ritters Automotive (Pat & Ross 9808-0266),
Frank Murphy (Frank Loos 9882-2296),
and of course the Auto Edge.
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