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Re: Ballast

To: "Dave Dahlgren" <ddahlgren@snet.net>,
Subject: Re: Ballast
From: "DrMayf" <drmayf@teknett.com>
Date: Wed, 4 Jul 2001 10:53:48 -0700
Silly sounding or not, It was a good protest! Why, well it is a jet engine
he is using ang the realpurpose of the jet is to move large quantities of
hot air backwards. I am not sure where the test was conducted, but if it was
on a smooth surface, not the mud dry lakes, then given some time it would
have accelerated. Look at thrust; it had lots of power but it took forever
to reach even a hundred miles an hours. It just takes time to over come
inertia with hot air, sorta like this group sometimes. As to the 10% of the
power of a piston engine beig made by hot exhaust gas, I am really
skeptical. Thrust from hot air is same as rocket engine where the formula is

T  =  mdot * Ve

which is mass flow per second * exit velocity in ft per second.

All that at the exit plane of the tail pipe. convert your cfm engine flow to
pounds mass per second and multiply it times what you think is a good
velocity...won't be 10% of hp I don't think. MAybe, but.....

mayf the red necked ignorant desert rat inPahrump

----- Original Message -----
From: "Dave Dahlgren" <ddahlgren@snet.net>
To: "glen barrett" <speedtimer@charter.net>
Cc: "Joe Amo" <jkamo@rapidnet.com>; "Smith, Simon-Pierre"
<Simon-Pierre.Smith@PSS.Boeing.com>; "land speed"
<land-speed@autox.team.net>
Sent: Wednesday, July 04, 2001 8:03 AM
Subject: Re: Ballast


> That was a silly protest and should have been demised from the beginning.
Every
> engine has a thrust factor in the exhaust period no exceptions... It has
been
> well documented and accounted for for decades, most notably in airplanes.
Piston
> engines account for about 10% of the rated HP in thrust. Where you aim it
is
> sort of up to the builder!
> Dave Dahlgren
>
> glen barrett wrote:
> >
> > List
> > A couple of years ago the issue of Vescos car came up and a protest was
> > started by Jim Fueling stating the Vesco car was assisted by thrust from
the
> > exhaust. I and several others were in attendance at this meeting. Vesco
> > proved that the exhaust flow / pressure was not enough to move the
vehicle
> > at full thrust alone. With any drive to the wheels the vehicle will not
> > move. I don't remember the exact numbers but they were very low. Some
where
> > in my file I believe I have the engineering reports submitted by Don
Vesco.
> >
> > It's like Fueling's Chevy powered streamliner (4 wheels )with one
removed
> > being called a motorcycle. My feelings on that issue is a motorcycle has
two
> > wheels unless it is a real side hack racer which there is a class for.
> > Lets see what this starts.
> > Glen
> > ----- Original Message -----
> > From: "Joe Amo" <jkamo@rapidnet.com>
> > To: "Dave Dahlgren" <ddahlgren@snet.net>
> > Cc: "Smith, Simon-Pierre" <Simon-Pierre.Smith@PSS.Boeing.com>; "land
speed"
> > <land-speed@autox.team.net>
> > Sent: Tuesday, July 03, 2001 7:51 PM
> > Subject: Re: Ballast
> >
> > > I am with your line of thinking Dave, BUT
> > > with the aero/go fast expertise that the
> > > Vesco's have, it would also seem logical
> > > that they have good reason for their design...
> > > Joe :)
> > >
> > > Dave Dahlgren wrote:
> > >
> > > > Thinking logically it would seem the down force to be canceled by
the
> > increase
> > > > in aero drag. It has to make a lot bigger hole in the air if it
comes
> > out 90
> > > > degrees to the direction of travel. If you aim it out the back it
will
> > do no
> > > > harm and might fill in the hole to a certain degree that you are
making
> > in the
> > > > air. 'Base drag' and all that stuff.
> > > >
> > > > Joe Amo wrote:
> > > > >
> > > > > yes, but when it is applied through the wheels
> > > > > you get to take advantange of all that multiplied
> > > > > torque from the motor, and that likely pushes
> > > > > alot harder than any thrust derived from pushing the exhaust
> > > > > against the air, perhaps that is why Vesco uses it for
> > > > > downforce......
> > > > > Joe :)
> > > > >
> > > > > "Smith, Simon-Pierre" wrote:
> > > > >
> > > > > > Seems to me that for every pound of downforce you get from your
> > exhaust, you get that much times your coefficient of friction out of
your
> > tires.  On salt you'd be better off pointing the exhaust back so you get
> > pure thrust.  Remember that the thrust doesn't go through the wheels so
it
> > is not traction dependent.  At Maxton I'd figure you can get a friction
> > coeff above 1 so it might be worthwhile pointing it up.
> > > > > > One other point, if the exhaust is pointed up and is aft of the
rear
> > axle it will lighten the front wheels.  This will give it a greater
> > effective downforce on a rear wheel drive car.  Hard to make up for a
> > coefficient of friction of about .5 though.
> > > > > >
> > > > > > Simon-Pierre Smith
> > > > > >
> > > > > > > ----------
> > > > > > > From:         Joe Amo[SMTP:jkamo@rapidnet.com]
> > > > > > > Reply To:     Joe Amo
> > > > > > > Sent:         Sunday, July 01, 2001 11:08 PM
> > > > > > > To:   Dan Warner; land speed
> > > > > > > Subject:      Re: Ballast
> > > > > > >
> > > > > > > Here you go Dave, an exhaust
> > > > > > > collector that is directed up for
> > > > > > > the acceleration heavy portion of the
> > > > > > > run, that rotates to or towards a more
> > > > > > > rearward aspect to enhance drag toward
> > > > > > > the end of the run.....
> > > > > > > Joe
> > > > > > >
> > > > > > > Joe Amo wrote:

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