I don't mean to flame or harass on this issue but I find it very
interesting and a core subject to the sport of land speed racing. So
please don't take any of it the wrong way hopefully...This is long and
may beg for the 'delete' key so be warned..
if a theory is correct it works no matter what the variables are.. So i
did go out and put my car in second ..drove 100 feet a valid distance in
my mind .. with the engine floored it was much slower than using 1'st
and second....car weighs 2500 lbs has about 150 hp and 170 ft lbs
torque..traction was not a problem in either case
I think your theory if it is going to work has to have unlimited
distance.. Acceleration does matter because if you are going faster
sooner then you have more distance left to achieve the peak velocity. By
the way the long course in my mind is only 4 miles long in the first
place because the only way to reach the highest AVERAGE speed over a
mile is to have the entry and exit speeds be as fast as the car will go.
A good example would be a car that enters the final mile at 250 and
exits at 275.. if I put more gear in the car it will accelerate to a
greater speed at the entrance because you have the is gearing advantage
for the whole 4 mile previous and will only go slightly slower at the
exit speed..I have been doing this since 1991 at bonneville and it works
every time.. the downside is 1 it is harder on the engine(more rpm) to a
small degree and 2 the driver hates the zero G input to the car and
complains about it seeming to float.. The downside to not using a
transmission are 1 it wastes valuable real estate waiting for the car to
get up to speed. 2 if there is any problem with the run there is not
enough distance to ever recover 3 it is very very hard on the bearings
to lug the engine down to a very low rpm and apply full load. it is also
very hard on the pistons for several reasons the most being if you have
a carb the main jets have no picked up yet and the engine will be very
lean and the high egts will hurt the engine (burned piston)..If you have
mechanical injection the engine will surely be fat and take a while to
clear out if it does not wash the rings out..If you have EFI and it is
tuned right the air fuel ratio will be good but now you are making even
more power on the slow turning crank and beating the bearings to death..
I really hate to blow my own horn.. but i have been racing
professionally since around 1975 24 hrs daytona Nascar winston cup
nascar Modified Bush cars..Drag races.. fastest car shootouts..won
zillions of races / championships / manufacturer titles / pole
positions..etc To be real candid if you went to every event held at
bonneville and set a record at every one i suspect you have still not
won enough....I am semi retired now as the pressure of all that every
day was too much for me but did learn so many tough lessons that they
are not forgotten.. I still consult, manufacture some parts that always
seem to end up on winning cars and travel around doing tune up work and
new product design for other companies. Do yourself a favor just for
laughs. Try it my way and see if you car is faster...what is to hurt by
running a different gear ratio for one pass or running the engine up in
rpm and keeping it in the power peak for a full pass???? If it is so
fragile that it can't stand the rpm then fix it...
At what RPM does your car make peak power?? peak torque??? In all my
years i have never seen a car that did not go faster with more torque at
the rear wheels, though i have seen many cars with suspension that was
incapable of transmitting the power(fixable) and have seen drivers that
would not drive and apply the torque sensibly(replaceable) and have seen
tires that would not hook up(selected wrong) and have seen cars that
were hopelessly constructed wrong(disposable).
If you know the HP and torque #'s for your engine and the appropriate
rpm,very valuable info, and your car is still accelerating beyond the
last measured mile I am willing to bet you that if you work on the
gearing and shift points the car will go faster than it does now. will
the peak speed be greater?? maybe , maybe not.. is there a record for
exit speed?? not that i am aware of.. to attain peak speed in most cases
the car has to run about 5 to 8% beyond the rpm for peak power through
the entire timed distance and not be able to go very much faster at the
5 than it does at the 4 for the highest average speed. you should be
right at the wall when you have no more power left to overcome the aero
drag and rolling resistance with the engine is up to speed... If the car
is not getting light then adding weight is worse than adding more tire
to get the bite to this this because the rolling penalties are less than
the inertia problems associated with the weight. You should be racing
the lightest car that does not want to fly.. I would think that anything
in the /CC classes can have any suspension they want. There are many
designs that will apply torque very softly to the tires and allow them
to hook up with small g loadings and do not rely on a great deal of
weight transfer. If spinning the tires is a problem i would look at the
suspension and tires way before taking power out of the car by running
the engine in high gear only.......
my opinion for what it is worth or not...but a real good topic to kick
around..
Dahlgren
The Butters Family wrote:
>
> Well sort of your Pro stocker would have to be able to leave the line in
> high gear and you would have to be able to run with the throttle wide open
> for max. engine efficiency, neither of which are going to happen. Believe
> Kieths car showed the increased speed because he was able to run with a
> whole lot less wheel spin. First of all we are talking about speed at a
> given distance, matching final gear ratio to the cars power will determine
> ultimate top speed of course. My theory is that speed at distance is
> determined by the total power available to do the job. With gearing you
> can change your et, even cut your terminal velocity with two short of gears
> but have little effect on how fast you are going at any given point. If your
> street car has a stick shift go out and run it between two points as hard
> as you can using all the gears, then do it in say second and high, your
> speed should be nearly identical. The only explanation I have for this
> is that even though the et was muuuch slower the motor was able to do the
> same amount of work. While you would think blitzing threw the HP peak
> several times would gain speed, apparently chugging threw it builds the same
> speedOriginal Message ----- Well thats my story, my car is a 53 stude
> running a hemi BB/cc with a 3 speed TF, I'm sure it would be just as fast
> with direct drive and a push to 60mph, wheel spin is a big problem. Hope
> theis helps let you know where I am comming from. Best regards, Kvach
> From: dahlgren <dahlgren@uconect.net>
> To: The Butters Family <bbutters@dmi.net>
> Cc: Marge and/or Dave Thomssen <mdthom@radiks.net>; Land-speed Racers
> <land-speed@autox.team.net>
> Sent: Monday, August 28, 2000 1:22 PM
> Subject: Re: Bonneville Transmissions
>
> > So if I understand this right then... If I put my pro stock car in 4th
> > and leave the starting line that that at the end of the quarter mile the
> > car will go the same speed as if i used all the gears?? When you lose 5
> > mph at the quarter does your car go the same speed at the 5 as if you
> > were not 5 mph down?? Why do all the 'big' streamliners keep wanting a
> > longer course ??? How fast does your car or cars you have messed with go
> > ??? I am sure that if I start in any gear that my Pontiac i drive on the
> > street will go exactly the same speed at the 5 no matter what gear I
> > start in.. but going 125 is not much of a challenge either. How do
> > explain away the change of shift points in Keith Turks car making 203 at
> > the 3 instead of 197 at the 5???? Doesn't having the correct gearing and
> > going as fast as soon as possible make the course appear to be longer
> > because you are going faster sooner and have more distance left to get
> > the last MPH out of the car??
> >
> > to quote "We got a 225 record with 183cid 3rd gear only??? Nebulous"
> >
> > Is this the theory you are using?? Do you think the 225 might of been a
> > 245 with all gears working??
> >
> > well we got a 216 record 219 qualifying with a 91cid gas lakester and
> > went 213 at the 1/4... used all 5 gears.. which one is more efficient
> > ??? and that was on the first pass.... Do you think if we left in high
> > gear that the car would of gone 219 at the 5 on 91 inches ??? What's the
> > physics behind your theory??
> >
> > Oh yeah and the e-mail you quote.. what's that thing doing on the long
> > course at 179 if you should be going over 175 at the quarter in the
> > first place???
> >
> > Hate to make this sound like a flame but I really can't figure out the
> > logic behind it all.. Help me be smarter and tell me how this is all
> > supposed to make sense..
> > A very confused engineer..
> > Dave Dahlgren
> >
> >
> > The Butters Family wrote:
> > >
> > > This has been my experience with every car I've ever
> messed
> > > with, the speed it was able to generate in a given distance hadnothing
> to
> > > do with the number of gears you shifted it threw, just the power it had
> > > available to do the job. Kvach----- Original Message -----
> > > From: Marge and/or Dave Thomssen <mdthom@radiks.net>
> > > To: Land-speed Racers <land-speed@autox.team.net>
> > > Sent: Sunday, August 27, 2000 7:35 PM
> > > Subject: Bonneville Transmissions
> > >
> > > > Well, gang our experience might be interesting. In 1979 we ran the
> > > Original
> > > > Goldenrod streamliner (the one from Denver) with my flathead (unblown
> on
> > > > gas) and a T-10 4 speed. It ran 179 MPH in the last mile and we
> thought
> > > the
> > > > gear spread was just right for the motor until something malfunctioned
> in
> > > > the transmission and it locked in high gear. We pushed it off as fast
> as
> > > we
> > > > could (60Mph) and it chugged off barely able to pull away from the
> push
> > > > truck. The quarter time and the 2 and the 3 mile were slow, but it ran
> > > > 179MPH in the last mile anyway. Anyone have similar experience that
> might
> > > > suggest that a long course car doesn't need a transmission at all?
> > > >
> > > > Dave the Hayseed
> > > >
> > > >
> > > >
> > > >
> >
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