healeys
[Top] [All Lists]

Re: [Healeys] Incorrect Speedo Reading

To: Bruce Griffin <bruce_griffin@earthlink.net>
Subject: Re: [Healeys] Incorrect Speedo Reading
From: Oudesluys <coudesluijs@chello.nl>
Date: Fri, 28 May 2010 07:29:40 +0200
Speed checks with a display along the side of the road are notoriously 
inaccurate. Use a navigation system like TomTom or Garmin. On the 
display you can read the exact speed you are travelling, they are very 
accurate as long as you drive a constant speed.
You can have the speedo recalibrated using these readings or calculate 
the gear you need in the transmission.
Kees Oudesluijs
NL

Bruce Griffin wrote:
> Gentlemen,
>
> This a very basic question, but I am hoping for some insight to see if there
> is a common Healey reason for this.
>
> I know my speedo has been bouncing, so I want to replace the cable to see if
> that helps.  My main question is how to estimate my speed based on my
> obviously incorrect speedo reading. I checked my speed with another car and
> knew it was off. Today, I passed a PD temp. speed camera that displays your
> speed. It indicated I was going 40mph, while my speedo showed my speed at
> 55mph. If I remember my engineering training from college, this is related to
> the gear in the transmission and I should be able to adjust my speed by using
> the fraction 40/55.  This assumes a portion for correction as opposed to a
> simple add 15mph because the gearing of the speedo drive gear is adjusted by a
> percentage, not a fixed number.  Any advice appreciated.
>
> This is also a good math problem for my 11yo son.
>
> Regards,
> Bruce D. Griffin
> _______________________________________________
> Healeys@autox.team.net
> Donate: http://www.team.net/donate.html
> Suggested annual donation  $12.75
> Archive: http://www.team.net/archive
> Forums: http://www.team.net/forums
> Unsubscribe/Manage: 
>http://autox.team.net/mailman/options/healeys/coudesluijs@chello.nl
> ------------------------------------------------------------------------
>
>
> Geen virus gevonden in het binnenkomende-bericht.
> Gecontroleerd door AVG - www.avg.com 
> Versie: 9.0.819 / Virusdatabase: 271.1.1/2899 - datum van uitgifte: 05/27/10 
>08:25:00
_______________________________________________
Healeys@autox.team.net
Donate: http://www.team.net/donate.html
Suggested annual donation  $12.75
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums

<Prev in Thread] Current Thread [Next in Thread>