[Healeys] High rpm's plus COOLING UPDATE

bluechip bluechipracing at snet.net
Wed Jul 11 11:28:42 MDT 2007


Consideration of changes in effective tire circumference etc. is ok, but I 
have taken a different approach:   Actually measure your MPH using mile 
markers and a stopwatch, or better yet use a GPS device which gives you 
precise MPH.  I have a $200 handheld which gives MPH, altitude, lat and long 
coordinates, and serves as an odometer as well.  I believe some cell phones 
have these built in as well.  Very handy.

Jim Smith


----- Original Message ----- 
From: "Richard Hosmer" <rahosmer at citlink.net>
To: "M Lempert" <mlempert at bellsouth.net>; "Ron Osowski" 
<rosowski at tampabay.rr.com>; "Healey List" <healeys at autox.team.net>
Sent: Wednesday, July 11, 2007 1:06 PM
Subject: Re: [Healeys] High rpm's plus COOLING UPDATE


> Mike,
>
> I believe you are correct so far as the resting imprint is concerned, and
> that the nominal computed circumference is "close enough" at modest 
> speeds -
> however, at very high speed the tire will have "expanded" enough to make a
> small difference in theoretical MPH calcs. I also suspect that this effect
> is significantly less with our modern radials than it used to be with the
> bias-ply Roadspeeds.
>
> Dick Hosmer


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