land-speed
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Re: Ballast

To: Joe Amo <jkamo@rapidnet.com>
Subject: Re: Ballast
From: Dave Dahlgren <ddahlgren@snet.net>
Date: Wed, 04 Jul 2001 06:49:54 -0400
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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