[littleeffer]

The SH AWD system is a true full time diffrential based AWD system whose primary purpose is to bias more speed to the outside tire in a turn to help in handling. It is not meant to be a hardcore offroad AWD system.

The demonstration targets a weakness in the AWD system in an artifical scenario that will probably never happen in real life. Thus the beauty in marketing.

The worlds most advanced AWD systems such as the attessa, and porches PSK share the same weakness when placed in the same artifical scenario. But if you put any of these systems on the track or real world conditions they will outperform almost everything out there.

 

[littleeffer]

I don't know... watch this...tell me what you think.

http://video.google.com/videoplay?docid=63...og-sl&hl=en
[/b]

SH transfers power side to side. The volvo system does not to that it is a coupling based system that transfers fore to aft.

 

[littleeffer]

I wonder how the newish Haldex Instant Traction makes a difference?

"Instant Traction adds a one-way pre-charging valve to the AWD system that maintains a torque load of 59 foot pounds, which is available instantly. Prior to Instant Traction, if the AWD system sensed that the front wheels were losing traction, one-seventh of a wheel rotation occurred before it began redirecting torque to the wheel with traction. That rotation could influence performance under certain conditions."

http://www.haldex-traction.com/technical_i...acteristics.htm

"So what makes the new improved Haldex AWD better? It now incorporates a non-return valve within the hydraulic control system so that its hydraulic fluid doesnt completely drain out of the system when pressure would normally abate, the result of slowing the vehicle. How does the upgrade make a difference? The outgoing Haldex system allows a one-seventh tire rotation before redistributing power to the rear wheels, but with the new system the non-return valve pre-charges the AWD system with as little as 59 lb-ft of torque turning the front wheels. In other words, the rear wheels are now called into service much sooner, and reduced wheel spin means greater control and less chance of getting stuck in the muck."

"A non-return valve in the hydraulic control system prevents the AWD system from being completely drained of hydraulic fluid (and pressure) as the vehicle slows to a stop. When starting from standstill, 59 lb.-ft (80 Nm) of torque is pre-charged in the system. As a result, the pre-charged torque engages the rear wheels much faster than previous AWD systems, which required wheel spin of a one-seventh turn of the front wheels before power was redistributed."

I just wonder how fast the SH-AWD can react?

I'll shut up now.
[/b]

It dosent need to react, its full time AWD. All the driven wheels get power all the time. The rear wheels arent called into service they are in service all the time.

The new haldex is basicly haldex with a bit of preload in the system.

 

[littleeffer]

I've become more appreciative of our haladex-type system. It can perform a 100-50 split...the same that and EVO can perform.
[/b]

Except its not the same as the evo can perform the system is COMPLETELY diffrent. The evo starts off at 50-50 driven by true diffrentials. It does not have to become AWD. Haldex is a coupling based system unable to account for diffrences in rotational movement of the wheels. It is primarily front wheel drive with a PTO that couples the rear wheels.

 

[littleeffer]

IBTL