George,
I am also new to LSR, and building a non-traditional car. With no history
of empirical data to rely on your program would be a fantastic help. I am
only an amateur programmer so I stuck with Excel spreadsheets this time.
However my problem has been excessive discrepancies between the various
algorithms proposed to calculate the rolling resistance of the tires. At
high speed the pessimistic algorithms predict more than twice the drag of
the optimistic algorithms. As I am working on a small streamliner with low
frontal area, the rolling resistance might contribute to more of the drag
than the aerodynamics. With uncertain algorithms for the most critical
component of the drag calculation my Excel program is no better than a SWAG.
I would be glad to share what I have done with you, but unless someone out
there can help us determine which models best represent the unique rolling
resistance of the salt at high speed, there is not much point in it.
The two most credible models I have found are from Hoerner and Dayman.
Which of these two have proven to be the most accurate? Is anyone using
anything else ?
Greg
----- Original Message -----
From: "George Mitchell" <americanpartner@yahoo.com>
To: "Jonathan Amo" <webmaster@amoproductions.com>; "Gene Brauninger"
<genesds@ic.net>
Cc: "Land Speed Digest" <land-speed@autox.team.net>
Sent: Friday, February 11, 2000 10:02 AM
Subject: Programs to help LSR Racers
> Skip H and I have been bantering back and fourth about
> calculatiuons for the design of the (now confirmed )
> early Hemi powered Porsche 924. We are trying to
> figure out frontal area and gear ratios . I am trying
> to get a horsepower figure to shoot for , camshaft
> design , rpm range etc.
> Although I can do it with a calculator, Desktop Dyno
> and just engine design experience I was thinking last
> night that it would be cool to have a program on my
> computer that would do these sort of calculations for
> me .
> Then I thought " Hey idiot, your a programmer for a
> living !"
> I remember seeing a program a few years ago but I
> don't know if it is available any longer. Besides I
> have the best resource in the world right here to help
> design it !
> Here is what I am thinking would be helpful beside the
> above mentioned items. I thought it would be nice to :
>
> Figure corner weights.
>
> With x amount of horsepower and y frontal area on the
> salt the vehicle should go z MPH --on dirt--on asphalt
>
> The record is z MPH ,with y frontal area, how much HP
> will it take to match or beat it? (reverse of the
> prior equation)
>
> I'm making good hp but x MPH away from the record how
> will this gear change affect me ?
>
> Basically, if you all help me with the specs , I will
> build it test it and make it available.
> Any ideas or comments.
> Would you find something like this helpful ? I think
> it would help "newbies" like myself.
> Thanks everyone
> George in DC
>
>
>
> Do You Yahoo!?
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