Hi Folks,
this start to be a very interesting discussion.
Dave & Russ, you packed the problem which I tried to explain in the right words.
So as you wrote - a base problem is the much lower friction of salt to other
surfaces like pavement.
Also, Dave, you got a number for this - the possible acceleration.
The advantage of weight to create downforce, is, that this stays the same
during
the whole run. A other advantage is, that you can position they there where you
need them - but this is also possible with an air flow - you can place them an
the most efficient point.
If you use a aerodynamic support like a wing you change the parameters with
every speed change.
Also, so faster you go so more you increase the aero resistance.
A other point are the tires himself. In August I got a nice discussion with
some
racers in the pits of the Raspberry (#412) car. They also shows me some tires
and some picture of defects in the rubber surface.
A tire can destroy himself, if the wheel is not properly balanced, the tire
pressure not alright - see the Firestone/Ford problem - or the material got a
production defect.
If the balance/tire pressure is not alright or you got a material/production
failure, you reach much faster the limit of the tire and this limit will be
much
lower than the speed rating.
The design idea of the traction control from Dave sounds very interested - I'm
waiting to see how this idea developed. It's picked the problem of the traction
from a different side as a street traction control. All the best luck.
In October I discussed the problem with the torque with Jim True.
Jim got the result to a theory, which I got for a long time.
Due to this that he runs in the same class as I do with the #286, he got the
same problem with not enough weight to get the torque on the salt. To increase
the downforce helps not to much. You still got the slipping tires.
My theory was, to use a very long gear (hope this is the right word) to reduce
the torque, so the tires start not to fast to slip - otherwise you have to
pedal
a lot - and this to a different feedback from the salt as from the pavement.
Jim done a long gear in, and the result was a awsome 253mph on fuel and a
fantastic 245mph on gas from Mary, very sad that she can't finish the return
run. He told me, that the slipping tire was much less than before.
This problem with the traction increase with the increase of the power.
See ya
Thomas "Pork Pie" Graf
PS. We engineers got a word "if you fix one problem, you cause another one"
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