[torsen] LSD in a rear wheel drive

Duncan Thomson duncan at systemcontrols.co.nz
Thu Sep 25 18:38:35 EDT 2003

The 944 list I'm a member of on Rennlist (Porsche board) is delving into 
the realms of a junior Torsen type thread...

A couple of people seem to have slightly wrong ideas, but strong opinions.

Can I get the experts here to give me a simple outline of open diff vs 
LSD (assume clutch type).
Nothing serious, we're looking at straight line effects and the classic 
one wheel on ice scenario.

One comment that has disturbed me so far is:

What you are saying (effectively) is without resistance there is no 
torque.  I don't buy it.  If for no other reason than there is torque 
input *to* the differential, so therefore there must be torque (less 
frictional losses) torque preserved *out* of the differential.  It 
simply *has* to go *somewhere*.

I know it's just being approached from the wrong angle here, but it's 
very hard to change some people's minds...!

So if any of the Torsen gurus would care to lower themselves to a 
*simple* explanation of open vs lsd or know of a good link, that'd be 

Actually, now that I look at the thread, the idea of an open diff is 
actually causing grief...
*groan*... I gotta get these guys into the spider-bite debate... it'd be 

cheers guys

'85 CQ (locker, non-turbo)
'90 Porsche 944S2 (open diffs)

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