I got up with multiple senior moments today and am having a bit of trouble
with traction control. I guess one or more of my problems deals with absolute
statements of unenforceable and undetectable. I also gott a sk what is
everyones definition of traction control? Before any rational discussions can
be had, the parameters of the discussion need to be known to all. Now, to me,
there are several forms of traction control. The first in my mind is when the
vehicle is at full boogie and hits a soft or wet spot and the engine rpm goes
up dramatically and then down again when better traction on harde or dryer
salt is under the drive wheels. Then there is the case when only one drive
wheel gets loose which to me is a rally bad situation because this causes a
force vector off centerline pushing the vehicle out of line. For the first
condition where there is even traction but loose, then traction control may be
had by lowering the engine speed but I really don't think it could be done
efficiently. This would require that the motor power be reduced then regained
very quickly to stay on the run. This could be done by looking at the
instantaneous rate of rpm rise and cutting back on the throttle just as
quickly. Ditto for reengagement. The second problem, of one wheel slipping, is
a little bit more complicated in that the rear diff cannot be locked or use a
spool, it must be free to allow the high rotation speeed of one wheel vs the
other. Then the wheel with the best traction has to be decoupled enough to
assure that both wheels are now equal. This is, I belive, a basic premise in
todays traction control, although I could be wrong. In this case a wheel speed
sensor is required at each driven wheel for the on board computer to compare.
Highest wheel speed gets the brakes applied. So what is wrong here...well
applying brakes means slower speeds, not faster. Traction control of the first
kind would work wonders on the drag strip because you would only apply the
amount of horse power that the track could take and this would result in
really low ET's. But not necessarily higher top speeds. Quick is not
necessarily fast. This kind of traction control would require some
differential wheel inputs such as wheel sensor and a separate undriven wheel
sensor to compare to determine wheel slippage. A pretty simple computer could
do this, say a small stand alone unit programmed in basic or similar. It would
output throttle position to control horsepower if the right effector was used.
The second case might be a little tougher because of the electronics in the
car itself. Most of the new cars have pretty determined computers and back
engineering is not available. Let anlone any way to reprogram them. But then
who wants to apply the brakes when top speed is where we are trying to go.
Like most of us, I wont be trying it in any fashion as described, I'll just
let the seat of my pants tell me what's going on...
was this a senior moment also? a brain fart? prolly....I'll wake up in a
minute or so and ....
mayf
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