[torsen] Re: [s-cars] S2 Rally Car transmission

QSHIPQ at aol.com QSHIPQ at aol.com
Sat Nov 4 07:27:02 EST 2000

Dave Jones has wrenches at a few of these races (not for quattros tho), after 
I debriefed him one of the early races this year, he mentioned that the big 
problem with the torsen appeared to be failures due to overheating the 
device.  A couple of DNF's, and the rules restrictions, it's obvious that the 
boys decided to just weld the diff.  Given the choice, I'm sure that they 
would love to have the 70r/30f>65/35>55/45VC's used in the BTCC series A4's 
(most TC races ran the 55/45).  Dave, Jeff G and I all have several articles 
on the VC's used in BTCC if you are interested.  

I also have a family relative that works for GM's driveline division who does 
data acquisition/evaluation for the race and offroad Chevy truck division.  I 
went thru a few very long discussions with him over some beers a couple years 
ago (they don't have any restrictions on diffs in this division), and of 
course asked about the torsen use.  Since these are Big v8's, he laughed and 
said that the torsen failure rate under high torque was so high, that even 
the fully sponsored race teams (that could swap the device after every race) 
wouldn't run them.  He also indicated that since these trucks constantly had 
wheels in the air, the handling was "goofy".  Result:  Lockers C/R, open or 
clutch type LSD front.  He also indicated that the device was evaluated and 
rejected for regular production vehicles.

Also, you might be interested to note that Jeff Goggin spoke directly with 
the chief engineer on the torsen device (in audifans archives) and it's 
shortcomings, and I spoke with audi rally god Stig Blomqvist (Audi S1/S2 
champion driver) about the use of the device (not) in rally, that interview 
is also in the audifans archives. 


Scott Justusson

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