Interesting things to think about here!
My 2 cents worth from looking around the last 10 years tells me there are very
few wings at B'ville that make that much down force. KT would have told you
about how the car settles down during a run from down force, well i instrumented
it this year and the car moved very little probably on the order of 1/8 inch.
>From what I can see of the rules for the most part real wings are not allowed
>in
most classes and a spoiler is for cleaning up air flow and is not a foil that
can generate large amounts of down force. personally i think tire failures have
more to do with the the weight of the car. Most tires that I am aware of all
have both a load rating and a speed rating. I would also have to think that an
overloaded tire will have less strength and therefore a lower speed rating than
one that is not overloaded. I have looked through the rule book and did not find
anywhere so far a place that discusses the load rating of a tire. Does anyone
think that i could run a Goodyear land speed tire on a Ford Expedition or a GMC
Yukon at 200 mph and be ok with handling? or that the tires would not be
overloaded? yet i have heard all about 5000 lb doorslamers with tires like these
on them. If you really want to get a handle on tires and failures you might want
to ask some one how much the car weighs and if the tires are rated for that
weight and speed that they are planing on running. If they have a 5000 lb car
and small front tires and have 55% front weight you have a failure waiting to
happen!! I would bet most are severely overloaded.
The front runners have no load rating at all listed on Goodyears site and many
of the land speed tires are rated for 1200 lbs others at 1700 lbs with one
listed at 3000 lbs. I looked at M/T site and there was nothing listed about LSR
tires there ...
If you really want to put any tire issues behind yourself you have to have a
tire from a company that will give the recommended load and speed rating and
check cars for compliance as part of a safety inspection. If you look at this
link http://www.goodyear.com/us/tires/racing/products/racect19.html
You will see that all these tires are rated at 300 mph or less at the rated load
or less load..
So if you have a car that goes over 300 on these tires you have an issue to
begin with and like i said the front runners don't even have a rated load or
speed that I saw so what is safe for those?
The other side of this that I would have to ask is the age of the tires. But
maybe that is another issue How do cars with visible checking on the side walls
even get through inspection? They are there and i have seen them many times!
What is the speed load rating after 4 years with a side wall that is checked and
how do you separate cosmetic damage from structural damage?
Dave Dahlgren
Who personally would not buy a tire without a load and a speed rating and would
believe it!
glen barrett wrote:
>
> OK, I sent a reply earlier today and it got lost in cyberspace along the
> way. I will try and remember what I stated.Regarding tires on the salt, from
> my vantage point in the timing stand we see it all. First, this meet the
> salt was HARD & DRY. This can be a big factor with any tire one runs. It is
> also abrasive in this condition.
>
> In the past about every kind of tire one can think of has been tried
> including aircraft 727 main gear type. Over the years I have seen the
> Daytona's and Taladaga's, front runners, wide ovals etc. tried. At around
> 240 mph this seems to be the point where the wide tire seems to start
> having problems.
>
> This is more so in the shorter wheel base sports type vehicles. A lot of
> roadsters tend to spin because there's a lot of weight on the front axle and
> once the vehicle has reached max acceleration the rear starts to move around
> and can get away from the driver pretty quick. The same for other vehicles.
>
> So, on to the wide Vs narrow and salt conditions. Tires with grooves tend to
> pack salt in the grooves when the salt is wet and get into a hydroplane
> condition, as do the wide slick tires with more surface area under them. The
> narrow Bonneville tires like the Lakesters and Streamliners run still seem
> to work best. Please don't miss read what I am saying because I am only
> going by what has worked best in the past.
>
> Some years back racers were still using tubes in the tires and found the
> higher speeds caused the tubes to be forced to the outer part of the tire
> and pull off the valve stem. High pressure 90 - 100 psi rear and 80 in the
> fronts for tubeless type tires seems about the norm. Sealing can be a
> problem but Keith Turk and others found ways on this great thread on how to
> solve that.
>
> Another problem is age and down force loading of the tires. The grooved tire
> that is running a lower air pressure can start to separate along the grove
> and chunk off or split along the groove. I don't claim to be an expert on
> tires, but I have been on the investigation of every accident with SCTA /BNI
> since 1983. We look at everything that could be probable cause and try to
> determine it. It's not easy as in our sport nothing is contained between
> crash ways etc.
>
> Example, Earl Woodens incident from the first indication of a problem to the
> last piece of the vehicle was some 3100 feet.
> In this case, once again the safety rules worked. I think what my message is
> approach every venue with extreme caution. Any landspeed racer will answer
> your questions regarding tires or just about anything else you are seeking
> help on.
>
> Brian, Grib, keith Dave,Skip and all of the rest, Once I am only going by
> what I have seen from the Best seat in the House. You guy's and Gals put on
> one hell of a show in 2001.
> Thanks, and keep up the landspeed information thread.
> Glen ( I timed the worlds fastest wheel driven car to date, what a thrill
> for me)
>
> ----- Original Message -----
> From: "Bryan A. Savage Jr" <basavage@earthlink.net>
> To: "Grib" <rgribble@carolina.rr.com>
> Cc: "List Land Speed" <land-speed@autox.team.net>
> Sent: Thursday, August 23, 2001 11:33 PM
> Subject: Everybody Knows That Won't Work
>
> > Grib,
> > I love it when someone like you proves, again, that "What Everyone Knows"
> is
> > sometimes (frequently) totally wrong.
> > You have made a true breakthrough by running rain tires. I have watched
> > several teams try the NASCAR slicks with mixed results (the best was just
> OK).
> > Your comment:
> > "..there's plenty of open space in the tread designed to expel water (and
> air)"
> > must describe what is happening.
> >
> > Now if someone could get Goodyear to do a CDF study ........ this
> principal
> > my be adaptable to ultra high speed (500+) tires.
> >
> > I didn't think your tires would work. I failed to even consider the rain
> > tire design.
> > Thanks for proving completely wrong Grib.
> >
> > When will we have tires designed to aerodynamically increase grip?
> >
> > Bryan
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