Aussie invention underpins new 'Cruiser

The local launch of the latest 200 Series LandCruiser was a jaw-dropping introduction to the latest model for the assembled journalists.

Even hardened offroad writers were impressed with the Toyota's ability to go places best left to short-wheelbase 'trucks' with lift kits, huge wheels and live axles at the front and rear.

Part of the new Cruiser's offroad prowess springs from a new way of emancipating the suspension from the constraints of the anti-roll bars at the front and rear.

Toyota has brought in expertise from a company based in Western Australia to deal with this conundrum.

Perth-based firm, Kinetic Suspension Technology holds three patents, of which one, the RFS system (Reverse Function Stabiliser) has been licensed by Toyota for the American market Lexus GX 470 (basically a Prado with the 4.7-litre V8 fitted to the LX 470).

Now, it has also been adopted for the latest LandCruiser.

Chris Heyring is the brains behind the patent. Originally a university art lecturer, this modest man developed the first working prototype for the system and fitted it to a 1990 Toyota HiLux, working from a lean-to beside his house.

He submitted the patent for the system and assembled a team of about 15 engineers to develop the system further. In the end, they built 30 prototypes before going commercial.

Around 1995, Kinetic Suspension Technology travelled to Japan to establish a working relationship with Toyota. Toyota repaid the visit by sending staff to Perth to evaluate the new suspension technology.

After building a few new prototypes, Toyota bit the bullet and acquired a licence from the company to fit the components in the Lexus GX. The latest LandCruiser is the first Toyota model in Australia with the RFS system, which Toyota names KDSS (Kinetic Dynamic Suspension System). Fitted to the LandCruiser, KDSS/RFS will be doing its thing in markets all over the world.

In describing how the system works, Chris says "Essentially, if you imagine a hydraulic cylinder instead of one of the drop-links [between the anti-roll bar and the body] and you join the top chamber of the front ram to the top chamber of the back ram, hydraulically with a tube, you then have a situation whereby it allows free axle articulation unimpeded, while restricting the roll forces.

"You can leave things as tight as you want in roll and still have total freedom for one-wheel input and articulation."

As Toyota's Doug Soden pointed out with a LandCruiser on a hoist, the hydraulic pressure applied equally at front and rear (as in cornering) maintains torsional resistance in the roll bars, but if a wheel drops at the front or the rear -- not together at the same time -- the piston in the hydraulic system can withdraw enough to ease the pressure and allow the wheel's articulation. The piston can pull back, but it can't push against the pressure.

And the true beauty of the system? As described on Kinetic's website, RFS requires no computers, pumps or motors.