Geez, Louise, that's the most interesting technical question on the list right
now!
(Our friends in the 77 car being one prominent exception), I think suspension in
general is way underutilized by cars in the 250mph-plus category. Yeah, I
know--
it's just one more set of variables to have to deal with. But my inspection of
the course after Speed Week indicated that many of the vehicles were loosing
traction at the expansion crack "dips", because their wheels were loosing
contact
with the surface. The "starting line" side of the "dip" would show tire tracks
that appeared to be laboring somewhat successfully-- then there would be a few
feet where the tracks would dissappear (the tires apparently flying over the
dip!)-- then they would appear again on the other side of the crack, really
tearing up the salt (spinning, I feel sure!) It would be nice if we could keep
the tires in better contact. Suspension is an obvious consideration.
As for "active" suspension-- all the reading that I have done on it indicates
that
the purpose is to keep the ride height (distance between the belly and the
ground)
in as narrow a distance range as possible-- and the vehicle level (horizontal)
from side-to-side. In other words-- a wheel can deflect (or rebound) a couple
of
inches, but the sill & belly remain 1.55" (or whatever) from the ground. This
is
important to the road racers because they use "ground effects"-- the flow of air
under the car creates a suction that helps them get those incredible cornering
speeds. And the "ground effects" are extremely sensitive to the height of the
belly/sill above the racing surface.
So my feeling is-- if any LSR builder decides it might be an advantage to create
(all, or part-of) the tire loading from ground effects, then for sure active
suspension would be worth a consider. Heck of a development project, I would
think.
I think Pork Pie is over-estimating the magnitude of the problem (caused by the
"undulations") for TC. Dave Dahlgren and I have both explained ways to address
that in other responses to this thread. Suspension is, I believe, unnecessary
for
a successfully-functioning LSR TC.
Interesting idea, though!
Russ Mack
Louise Ann Noeth wrote:
> OK, engineer types and racer stars, posit this for me . . .
>
> If traction control algorithms has inherent problems due to the undulations
> and hardness of the salt surface, then would the problem be helped by adding
> an active suspension system to the mix?
>
> And Jack, I can hear you already crabbing about the money, but my thoughts are
> merely theoretical, not chumming for an agenda, so don't beat me up.
>
> Be Vigilant,
>
> "LandSpeed" Louise Ann Noeth
>
> LandSpeed Productions
> Telling Stories with Words and Pictures
> ++++++++++++++++++++++++++++++++++
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