-------- Original Message --------
Subject: Re: Everybody Knows That Won't Work
Date: Sat, 25 Aug 2001 12:20:16 -0400
From: Dave Dahlgren <ddahlgren@snet.net>
To: glen barrett <speedtimer@charter.net>
CC: "Bryan A. Savage Jr" <basavage@earthlink.net>,Grib
<rgribble@carolina.rr.com>,List Land Speed <land-speed@autox.team.net>
References:
<3B85F527.656FA906@earthlink.net><001801c12cf3$f0202c80$e0432cd0@charterpipeline.com><3B878C6C.5A00DB25@snet.net>
<00b601c12d75$1860b8a0$e0432cd0@charterpipeline.com>
The point i am trying to make is this. If you have a car like the Firebird going
333 MPH then if it has Goodyears on it they are rated by Goodyear to 300 at the
loading they say is safe. If you go 350 on a 300 mph tire how is that different
than going 250 on 200 mph Z rated tire which I thought was not allowed. M/T
sells tires that are rated to 500 I had thought maybe for safety's sake you at
least police the tire ratings that are known and set some reasonable guidelines
for the tires that are not rated at all. Could i be so bold to ask what size
and brand tire was on Earl Wooden's car that gave up and if a Goodyear was it a
'front runner drag race tire'? How old was it might be the next question. We
currently police the age of seat belts, fire suits and fire bottles for safety
reasons, should tire ratings and age be so different? For me this is not to
cause any problems just honestly seeking safe solutions. Every accident should
bring along with it a solution to avoid the next accident!
Dave Dahlgren
glen barrett wrote:
>
> Dave
> I am not claiming to be a tire expert, far from it. The point I am
> addressing is what I have seen on the salt the last 20 years.
> I agree with you about the lack of tire loading and ratings not being
> available, but in our specialized type of racing there are not a lot of
> people beating down our doors to make us racing tires. The M/T's and
> Goodyear's are what we have. As I stated yesterday the salt conditions dry
> or wet are a factor in partly how the tire works.
>
> As far as loading and down forces there are vehicles with high loading. The
> Firebird of Lindsleys & Leggitt had heavy loading and the ground effects
> along with the body (front) was almost self destructing. I am glad it didn't
> go over 333mph as I think the vehicle would have had a different ending.
>
> Earl Woodens tire failure was delaminating down the center of the tire
> resulting in it exploding. The other factor in the coupe was the engine /
> drive train was on the right side of the vehicle and in turn had more load
> on the right rear tire. Like I said I am just passing on lessons learned
> from the past. I wish we had more experts in the tire world to take an
> interest in our needs and give us safe 500 mph tires.
> ----- Original Message -----
> From: "Dave Dahlgren" <ddahlgren@snet.net>
> To: "glen barrett" <speedtimer@charter.net>
> Cc: "Bryan A. Savage Jr" <basavage@earthlink.net>; "Grib"
> <rgribble@carolina.rr.com>; "List Land Speed" <land-speed@autox.team.net>
> Sent: Saturday, August 25, 2001 4:30 AM
> Subject: Re: Everybody Knows That Won't Work
>
> > 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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