Mike -
Thanks for the response, sorry you lost all that, I hate when that happens.

So to my assertion earlier, if the AWD kicks in even before VDC, what purpose does VDC serve on the x? My guess earlier was that it still will apply brakes here or there depending on speed and steering inputs, but if the AWD kicks in before VDC, my guess is that there is no need for VDC to cut throttle inputs since the wheel torque management is handled through AWD. Sorry for all the detailed q's!

 

My belief is that with AWD's 50/50 power split, the car no longer has enough power to break traction, except in a few EXTREME cases, like turning the steering wheel all the way one way from a dead stop, brake torquing, and flooring it.

Next time it rains, I'll conduct a few experiments. I DO know that when you're making a left turn from a light, with AWD on a dry surface, you can floor it and never have VDC kick in.

I do know my STi and vr-4 have no problem breaking traction with all four wheels when it's wet outside.... and neither have traction control of any sort.

 

Even on dry roads, I see the DVC light blink if the car is floored.
When turning left from a stop and flooring it... the VDC light definitely blinks.

This depends greatly on the tires as well.
My Blizzak WS-50's fire up the VDC almost regularily now.

 

I actually found it - was wondering how this (below) was possible based on the configuration of AWD, even w/ VDC turned off. Here's a quote from the 2005 Long-Term Test from Road & Track:

"The sporty nature of its rear-wheel-biased all-wheel-drive system managed to bring a smile to our resident performance junkie and Feature Editor Mike Monticello's face. Undoubtedly, this is due to the G35x's ability to oversteer on corner exit."

Let me know how the rainy-day experiments go!

 

Just to complicate things a little I was wondering on peoples thoughts on LSDs as deployed on the new 2008 Subaru WRX Sti:

"This central differential combines a quick-response, electromagnetically operated clutch pack that actively varies the torque split between the front and rear wheels from 41 percent front/59 percent rear to 50 percent front/50 percent rear during cornering, thanks to input from an array of electronic sensors. A helical-type front limited-slip differential helps the front wheels carve through the corners, while a Torsen-type limited-slip does business at the rear. " - From Edmunds First Look at 2008 Subaru WRX Sti

I'm assuming that this system is a more advanced AWD system as compared to the G. What if you throw an LSD in the front and rear of the G, would that be helpful or would that cause issues with the electronics? Not sure if a center LSD is available as well (who's got $6K or so to throw at their G35x to test out what happens if you throw a few - 3 - LSDs in the driveline)

 

a Mechanical LSD's interaction *should* be faster than the VDC, since the LSD begins to react when the tires are rotating at different speeds, as opposed to VDC which detects wheel spin.

A good example would be the sedans with the Sport package.

In theory, a front and rear LSD shouldnt affect VDC... although it'll reduce daily driveability slightly, and slightly slightly increase drivetrain loss.