ilPistone.com: Opel Insignia OPC

Citato da: stella su Aprile 16, 2009, 11:24:33 am

Se in situazioni 'normali' l'auto mi rimane una 2wd (ant. o post.?), penso in fase di rilascio in curva, in montagna, su sterrato, neve, ecc... credo che la differenza ci sia.

Citato da: Laurus su Aprile 16, 2009, 11:33:52 am

Fino a qualche tempo fa, il problema più serio era il "doppio tempo"... non so ora...

Questo parla della saab, che dovrebbe montare lo stesso sistema... anzi, possibilmente quello della opc e' una "revisione" maggiore. A quanto pare siamo lontani anni luce dal funzionamento on-off. I vecchi poi non potevano trasferire piu' del 50%... mentre questo arriva al 100%. E mantiene sempre un 5-10% di coppia dietro. C'e' poco da fare gli schizzinosi Grin

XWD driving experience

Developed in Sweden with Haldex of Stockholm, the Saab XWD "Cross Wheel Drive" system is designed to optimize vehicle handling and stability in all driving conditions. It is offered in the 2008 Saab Turbo X and Aero versions of the 9-3 Sport Sedan and SportCombi, in combination with an uprated 280hp, 2.8L V6 turbo which now delivers almost 15% more maximum torque (295 lbs./ft.) to exploit the greater traction available. Engine design features include a lightweight, all-aluminum construction, with a 60-degree angle between the cylinder banks for perfect balance; variable-inlet valve timing and twin-scroll turbocharging. XWD is offered with a choice of six-speed manual or automatic transmissions.

The state-of-the-art all-wheel-drive system on the Turbo X includes two innovative features: pre-emptive engagement of the rear wheels to optimize traction at take-off; and an active rear limited-slip differential (eLSD), allowing variable torque transfer between the rear wheels.

Saab XWD is a fully automatic, on-demand system capable of sending up to 100 percent of engine torque to the front or rear wheels, whenever necessary. While offering drivers sure-footed handling in low-grip conditions, the system's sophisticated operation also enhances the sporty driving experience in all road conditions. Fine balancing of the drive torque between the front and rear axles raises the threshold at which ESP throttle and braking interventions are triggered, providing more scope for closer driver involvement.

At take-off, a torque transfer device (TTD) is initially activated engaging the rear drive module. This pre-emptive function is a valuable improvement over current technology, which requires the detection of wheel slip before the TTD is activated. For the driver, the enhanced functionality gives maximum traction immediately for smooth, strong acceleration from rest without the possibility of any initial hesitation.

On the open road, drive torque is seamlessly and continuously varied between the axles by the control of a valve in the TTD. When cornering, Saab XWD rewards the driver by providing enhanced, more finely balanced chassis dynamics through the application of rear drive to balance oversteer and understeer characteristics, improving stability and road holding.

In highway cruising conditions, when traction or optimum grip is not an issue, only 5- to 10-percent of engine torque is typically transmitted to the rear wheels providing a greater measure of stability while helping to save fuel.

The Turbo X also features an electronically-controlled limited-slip differential (eLSD), which uses inputs from the rear wheel speed sensors and can transfer up to 40 percent of torque between the drive shafts, to whichever wheel has more grip. It represents the first application of an electronically controlled, rear limited-slip differential in the segment.

The eLSD also gives the driver enhanced control when cornering hard or completing a high-speed maneuver, such as a lane change, by momentarily applying more or less torque to either of the wheels to help the rear of the car more closely follow the direction of the front wheels. This yaw damping effect can keep the car better balanced and more tightly controlled, without requiring "outside" intervention from electronic stability aides.

General Motors of Canada (GMCL) is engineering and manufacturing advanced environmental technologies ranging from Active Fuel Management (cylinder deactivation) and hybrid systems to E85 biofuel and fuel cell vehicles - more than any other auto company right here in Canada. Headquartered in Oshawa Ontario, GMCL employs more than 19,000 people nationwide. GM of Canada manufactures vehicles, vehicle powertrains, and markets the full range of General Motors vehicles and related services through 732 dealerships and retailers across Canada. Vehicles sold through this network include Chevrolet, Buick, Pontiac, GMC, Saturn, Hummer, Saab and Cadillac.