Well actually an active suspension is a great idea. I would assume you would
want
it to get stiffer with speed..The real problem is with unsparing weight though.
And some of it is hard to loose in this type of racing but some can be lost.
Brakes are the first place i would look as if you can only acell at .61 g then i
suspect any set of brakes that can decell at a greater rate are over kill.
Inboard
suspension would help too but it is fairly complicated and spendy. That gets us
down t the wheels and tires. The tire weight is pretty well fixed by the
manufacturer and the rest is open to a weight reduction. Carbon fiber wheels
perhaps? thin wall titanium maybe? I think in the end you would have to use all
these tricks and still have to have a suspension that has almost no give at 300
+
but it would certainly make getting to that speed easier. that is the whole
point
in my mind. When you race a LSR car where terminal velocity is the real goal
then
you have to see what you can do to make the track seem longer. I think along the
lines of getting to the greatest speed as soon as possible on the course so that
there is more course left to get the last mph out of the car. The way to do that
is to accelerate as fast as possible as soon as possible. The ways I see to do
this are as follows
1. As light a car as possible
2. gear spacing and as many gears as it takes to stay in the power band and not
shock the tires during a gear change.. I am writing some software to address
this
problem so it can be visualized very quickly and sensible choices made.
3. Traction / wheel spin control via power modulation to cover up the holes in
traction left by available gear spacing combinations
3. Suspension active or other wise that will help the car hook up initially and
then have appropriate response times to suit the speed desired. ( this is the
most
complex problem).
So my view of racing LSR has broken every rule known to be true..as i have heard
them anyway.
1. ballast is good make the car heavy
2. Gearing is unimportant just give it a push and let it go you have 5 miles..
3. Traction control is both illegal and frowned upon in general as it takes
control away form the driver.
4. Suspension is pretty much not needed and causes more problems than it fixes.
My answers to these myths are
1. there is no such thing as a good heavy race car. if you need ballast fix the
car.
2. gearing is everything. I can gain more speed by shutting the hood and working
on the rest of the car provided the engine is a 'player' to begin with. If you
tweak the engine endlessly the best you can hope for is a few percent from test
to
test on a well developed engine. With proper gearing I can get all that power to
the ground and stay in the power band I spent so much time and money developing.
3. TC well if you ask a driver what he/she did in the car and how the run was
you
get one story. Ask someone that watched the car you get another story. I use the
word 'story' intentionally as most of these recollections are just that, a story
but not necessarily the truth. Down load the data from onboard sensors and you
will get the truth. I have seen more passes at part throttle in cars where the
driver said the car was going well and hooked up than you might believe. So in
the
end the driver seldom has a real clue a to what went on other than the big
'Kodak
moments' when a wheel fell off..
4. Suspension is the final link between the mass you are trying to accelerate
and
the tires that have to get the power on the ground....
The real issues with the dislike of traction control or power limiting which for
me is not traction control per se. is the original types of cars that make up
this
sport and the speeds that were possible when this sport was conceived. I
suspect,
but probably am wrong as usual, that when this sport was originally conceived
that
the speeds that seemed possible were in the 175 to 220 range most of the early
records bear this out, and there are very few 1950 records that are in the 400
mph range and I am sure that was a speed that was magical and unattainable by
the
competitors in general. The power available was very modest also. To my
knowledge
there were no 700 hp flatheads or Arduns or jimmys around and still aren't any
either. The average car at Bonneville now probably has that much power and the
faster cars double that. Now we are going almost twice as fast as originally
intended or believed possible. Well at 200 most drivers that are competent can
keep up with the information the car is providing and make appropriate
corrections
before we have an 'event' take place. At 300 the information starts to reach
overload status and i have no clue how drivers process information at 400+ but i
am sure whatever the skill level needed to run that speed it can be more than a
little overwhelming. The power limiting devices to aid in controlling wheel spin
are mainly to help the driver off load some of this processing so he or she can
focus on something else. If this is such an alien thought why don't we still
have
an ignition advance lever on the steering wheel it's only one more thing to do.
It
is a good example though of how things electronic or mechanical are used to
reduce
the amount of information the driver has to process and adjust for..
Same goes for something that will limit the power applied to the wheels
as far as legality goes are any of these things not legal..
a rev limiter
boost control
ignition advance mechanisms (electronic)
I don't recall them being illegal
so how how can the conditions of operation be illegal??? or even frowned upon.
I sure hope all the purists pull out their rev limiter, waste gate and ignition
advance mechanisms...
Dave Dahlgren
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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