New Falcon: Independent control for Barra

FORD has revealed a new independent rear suspension design that will be fitted underneath all Barra-based sedans when the new car goes on sale in October.

Ford will also fit the design to sports derivatives and long wheelbase cars, but the utility and wagons will continue with the current beam axle rear end.

The decision by Ford to go with what it calls "Control Blade IRS" means the independent double wishbone design that debuted with AU back in 1998 has been abandoned.

Ford Australia chassis development manager Alex de Vlugt says there are a number of reasons for the change - the control blade offers superior tuneability, is lighter by 20kg without having to resort to aluminium, is more compact than its predecessor and is also as robust for towing as the beam axle.

Mr de Vlugt also admits control blade is cheaper to build than the double wishbone set-up, although he was unwilling to quantify the savings or put a figure on the development cost of the new design.

The new suspension will be mated to a modified version of Falcon's double wishbone front suspension.

The delivery method of the suspension is also new. DANA Corporation will produce it as a module from a new facility in the National Business Park next door to Ford's assembly plant at Campbellfield, Melbourne.

Ironically, DANA already performs a similar service for Holden from a facility at the Edinburgh Business Park in Adelaide.

Ford revealed the new suspension design and its partnership with DANA last week as itcontinued its roll-out of Barra previews leading up to the car's October launch.

The decision to go all-independent with Barra was expected, but the move away from double wishbones was not.

Mr de Vlugt was bullish about the capabilities of the system.

"The Control Blade IRS on the new Falcon is without doubt superior to the more simple IRS systems found on other Australian cars," he said.

Control Blade is not an Australian name or concept. It is the suspension system already seen on the Ford Focus small car and the JaguarX-Type compact luxury car.

But this is the first time the design has been adapted to a rear-wheel drive vehicle.

The new suspension will be offered in four states of tune across the Barra family - more choice than offered previously with Falcon.

Standard IRS will be found on Forte, Futura and Fairmont, complete with new 215/60 R16 tyres.

Sports IRS is standard on Fairmont Ghia and available across the range as an option for Forte, Future and Fairmont buyers.

Based on lower profile 225/50 R17 Dunlop tyres, Ford claims this set-up provides increased feedback and agility for a slight trade-off in ride softness.

Heavy duty suspension is available as a limited access option for Forte buyers. This provides a higher ride height, stiffer springs and revised shock absorber settings for improved performance in outback and heavy-duty use such as towing.

Finally, Tickford IRS starts with low profile 235/45 R17 Dunlop tyres, which will be standard on all XR models and optional across the Barra sedan range.

Control Blade IRS: How it works

MR de Vlugt says the Control Blade IRS "decouples" the link between ride andhandling to improve both facets of suspension performance.

It does that by keeping the handlingcomponents of the suspension isolated from the noise and impact harshness components.

The control blade is the key to this. It is a longitudinal trailing arm with a large bush at one end.

It has the key function of improving ride while also reducing road noise transmission.

This leaves the three lateral links free to define toe and camber.

These links have been designed to be as long as possible and with connections to the body as stiff as possible, to keep tyre toe deflection to a minimum.

The geometry of the suspension has also been designed to provide "anti-dive" under braking forces.

The IRS system is mounted in a steelsubframe, bolted directly to the underbody for increased stiffness.