# RE: The Definition of Spider Bite (tm -SJ) in a Torsen Center Diff

```Dave E writes:
>oh yes, the "definition of the bite".  which you have failed to come up
>with.  care to divvy up this time????

Dave, let me predicate this post with a toast to you for your research.
Based on it, me and several others on this list, feel this discussion is
going forward (mit nein turns:).  Appreciate you taking the time to put the
homework effort into the discussion, and since we are really close, IMO, I
will stick only to the points you raise, with as little phlogistic tangents
as possible.

That said, I have put forth a bunch of definitions and scenarios in the
archives, and Jeff has also.  My claim has always been in terms of chassis
dynamics, extending torsen torque shift to the chassis dynamics in a turn.

To summarize:  A torsen center diff chassis, in a turn, *can* suddenly and
without prediction, shift from an oversteer to an understeer to an oversteer
(ad infinitum) condition in a single turn.  This phenomenon I refer to as The
Spider Bite (tm -sj) and is a nature of the torsen center differential.  This
creates a 'challenge' in controlling a center torsen vehicle in a high
performance - high cf environment or a low performance - low cf environment.
I come to this conclusion based on my research into how a torsen differential
operates.

Definition of Spider Bite (as I understand the device, based on my research
and Dave E's):
Torsen center diff car enters a given turn, turning radius fools torsen into
allocating torque rearward -O-, which (depending on all the variables in
885140) *can* overload the rear tractive ability, which then changes the
variable affecting torque shift from a slip angle one (turning radius) to a
tractive variable (traction at the rear wheels), which per 885140, is
"independent of the forced slip resulting from the vehicles circular path",
and this shifts torque forward, causing -U-. which then *can* regain tractive
force rear, which results in -O-, because once tractive force rear is
regained, torque shifts rearward due to turning radius.  This scenario *can*
cycle several times in a single turn.

This assumes all variables the same as 885140 except accleration(Trg)=cf
(they are the same variable for all intents and purposes).  Changing *any*
variable, *can* increase or decrease the chances of Bite, but can't eliminate
it.

Single yes/no question Dave (/others):  Looking at the above scenario v your
research, isn't the definition of bite as I presented above, possible (I