You sure did. And an excellent postulation it is too! One question,
how can this lead to spins in one direction if the car doesn't tend
to go in that direction? Seems to me that the direction of rotation
would be random if the car is loaded correctly in the first place.
Skip
At 09:24 AM 6/12/2009, NT788@comcast.net wrote:
>Any steering input reacting to caster will load or unload one rear
>wheel. Caster causes spins. There I've said it!
>
>Jack
>
>
>
>
>
>
>
>
>----- Original Message -----
>From: "Skip Higginbotham" <saltrat@pahrump.com>
>To: "Kirkwood" <saltfever@comcast.net>, "land-speed"
><land-speed@autox.team.net>
>Sent: Friday, June 12, 2009 8:10:32 AM GMT -08:00 US/Canada Pacific
>Subject: Re: [Land-speed] Car Spins
>
>Well, in the absence of other speculation and no volunteers of data
>supporting the effects of exhaust thrust nor thrust numbers, I would
>suggest that exhaust thrust can push the front of a car in the
>direction opposite the thrust. If the exhaust exit is in front of the
>front wheels, most of it comes out on one side of the car and running
>front wheel weight on the car is on the low side. If thrust values
>are in the area of 50 lbs with a moment arm of, say 50 inches, then
>2500 inch pounds of rotating torque would seem a lot for a car
>"skimming along" the surface of the salt. And if it is not "a lot"
>then it is, at least, some.
>Having said that, I asked for help some time ago to see if anyone had
>acquired any exhaust thrust numbers. I seem to remember that sometime
>in the past, someone had measured exhaust thrust (zoomies) while
>dynoing but the state of decrepitude of my memory prevents me from
>having actual data and I don't have the skills necessary to calculate
>it. My thought is that if such a side thrust condition exists,
>coupled with an adequate moment arm, then a spin in the direction
>opposite thrust is not only possible but, I think, likely. Consistent
>spin tendencies in one direction would seem to support this
>especially if the spin direction is opposite "normal".
>Is there data (not unsupported opinions) to dispell this thought? If
>there is, I would appreciate the opportunity to know the data so I
>can stop thinking about this......
>
>Thank you,
>Skip
>
>
>
>
>
>At 04:18 AM 6/12/2009, Kirkwood wrote:
> >How about thrust angle? Does any car have perfect perpendicularity? Without
> >a laser how can you get closer than 1/16". Or, structural distortion from
> >stress changing the thrust angle.
> >
> >
> >
> >Date: Wed, 10 Jun 2009 15:19:06 -0700, From: drmayf <drmayf@mayfco.com>
> >
> >. . . Are there reasons, theory, guesses, why a particular car would spin
> >one way and consistently spin
> >
> >that direction?
_______________________________________________
Support Team.Net http://www.team.net/donate.html
Land-speed mailing list
http://autox.team.net/mailman/listinfo/land-speed
|