# RE: understeer/oversteer definition

```Rick, I'm _delighted_ that you've recognized that I made no attempt to
address understeer/oversteer.  That is a different layer of interactions
involving centripetal acceleration, friction limits, polar moments of
inertia, and such.  _All_ that I was doing is to clarify some concepts of
physics.  Plenty has been said regarding understeer/oversteer... and well
said.

"For the longest time there was a theoretical limit to acceleration,

mostly drag racers wondered were the limits of "traction", would
limit e.t.'s
and ultimate speed in the quarter mile, and the magic 1 "g" could
not be
exceeded. Well guess what, it was a long time ago what are they up
to now 300
plus miles an hour, and less than 5 seconds, Newton would be

Well, like "bumblebees can't fly" this another of those
cocktail-party-junk-science things that just won't die.  The statement was
made that _IF_ the coefficient of friction between tires and asphalt never
exceeded 1.0 then a wheel-driven vehicle could accelerate to no more than
172mph in a quarter mile.  There was never any statement that said that it
could _not_ rise above 1.0... as evidenced by the trap speeds of today, it
does.

"Applying straight forward physics to the situation with out looking
at the
variations of tire compounds, live mass moving around the center of
gravity,
amplification of forces at the contact patch and the resultant slip
angle, you
will have exactly what you have postulated...no answer to the
original
question...what is understeer and what is oversteer? "

Application of physics is the _only_ way that anyone can understand the
vehicle dynamics.  You seem to feel that it must be understood in one large
bite.  We have to deal with the effects of accumulated physics principles in
one large bite when either the front or back end of our car begins to slide,
but... understanding everything that is contributing to that result must be
done incrementally.

"Again, see Mr. Smiths "Engineer to Win" and see what a real race
car
engineer has to say on the subject, in this case I'd be only the
messenger".

Smith's book is not an engineering text, it is an accumulation of practical
results of someone who has studied engineering and applied it for a
particular result.  He understands physics and has put the results into
layman's terms.  With his very thorough understanding he could probably
write the new edition of "Physics for Poets," perhaps the ultimate challenge
for an engineer.  If Smith is your engineering reference then why haven't
you looked there for understeer/oversteer definitions?

You and I should more than likely keep our day jobs, neither of us
are
headed to Jordan to be Damon's race engineer.

I don't know your profession, but if you were to attempt to explain to me
something of it's basic concepts, I would listen and attempt to make use of
what you had to say.  And, whatever your avocation, it is unlikely that I
would suggest that you are sufficiently ignorant in that pursuit such that