What is quattro, what is "haldex"

[QSHIPQ@aol.com]

Dave E writes:
>what interests me in the design is the ability of the processor to change
>the handling dynamics.  i expect, at this premature time, to find the s3 and
>ttq quite differet handling animals...

not totally with you here Dave.  If Haldex can only send a maximum of total 
Trg of 50% to the rear wheels, both should handle as the press has reviewed.  
A slight hint of understeer all the time.  Why is that?  Because the ability 
to induce LTO is limited by the haldex locking (specifically the delay in 
unlocking to prevent LTO), and the ability to induce on throttle oversteer is 
limited by the interference of the EDL on the front drive axles (total Trg is 
reduced to keep handling at slight understeer).  Without tuning (I argue even 
with tuning of the Haldex "CAN") you can equalize one chassis dynamics to 
another (something torsen couldn't really do) with the same hardware in the 
system.  But that only means that when you own an S3 and a TT you can drive 
them the same.  Where too, does the Haldex leave the LFQB (left foot quattro 
brakers)?  Quite in the "lurch" might be an understatement.  It's one thing 
to try  controlling a variable torque torsen with LFQB, it's another to 
control a fwd>awd switch all together.

>the point is moot really.  why?  because even with a state-of-the-art active
>system, you will certainly have times were little or no torque is going to
>an axle, so you are not strictly speaking awd at that time.  also, with the
>generation 1 system locked, you will have times where the same is true, that
>0% torque is going to an axle.  whither awd then?

This isn't worth addressing again.  Bottom Line is you need to understand 
chassis dynamics to understand the point is far from moot.  Think of what is 
happening under left foot braking scenario in an open, locked, torsen and a 
Haldex situation.  The predictability U and O are far different based on 
driver only vs computer overide.  

>anyway, this whole argument is a little premature (par for the course?).
>lets drive the cars equipped with the devices, and then make up our minds.
>i'm certainly keen to drive the s3 as i'm almost convinced tracey to part
>with her mk2 vw gti :-)

Don't forget to do the left foot braking test Dave.  The limitations audi put 
on this device are from audi trying to reinvent the wheel in terms of haldex 
application fwd vs rwd primary drive wheels.  Again, taking absolute traction 
over enthusiasts.  Since VW/AUDI AG has committed themselves to this tech for 
the next 5-6years, the best hope we have is to convince vw/audi to reverse 
the haldex primary drive wheel decision.

Reprogramming the CAN isn't going to get very far.  Considering the clutch 
device with electronic slip (to vary torque), I doubt audi is going to 
support the CAN tweekers under warrantee when those tweeking start wearing 
out the intended part time 4wd device with manual overide locking.

After my research on the Haldex, the rumor of the audi boys peeling off the 
quattro badges is fully warranted IMO.

Your quattro realist

Scott Justusson