A4 Electronic locking diffs...

[paul.heneghan@bbc.co.uk (Heneghan,Paul)]

From: dan_masi@MENTORG.COM (Dan Masi)
>
>Actually, no, he's not confused... technically, he's got it
>right.  Seems that torque is an often-confused subject, though.
>Look at it this way: assume you've got a RWD car with the right
>tire on ice, and the left tire on pavement, and that it'll take 
<snip>

Thanks for this clear explanation of 'torque spliiting'.  I've always 
 been unhappy with the idea of a locked diff splitting torque 50/50 
 (how can a wheel on ice exert equal  torque compared with the one on 
 the good surface?), but I've never bothered to work out the maths before.

The 50/50 split is obviously referring to the wheel speed.  An open 
 diff allows the opposite sides to rotate at different speed (0/100 to 
 100/0).  A locked diff constrains the speeds to be the same (50/50).

I drove a Morris Minor in the snow once when one of the rear brakes had 
 locked itself on.  It took me a while to work out why the car was 
 going twice as fat as normal in first gear (a result of the 0/100 
 speed split).

Paul
paul.heneghan@bbc.co.uk
1984 Audi 80 quattro
1983 Audi 100 Avant