Jamey,
I think the problem is that you need the speedo from a spitfire, or at
least the odometer gearing from a spit.
Probably the best way to get the correct speedo overall is to use the
entire
works from a spit speedometer placed into the case of your GT6 speedo.
This way you do not have to worry about the speedometer function. The
return spring of the speedometer pointer is calibrated to be accurate over
the
entire speed spectrum for a certain gearing. You can adjust the
speedometer
to read accurately at a certain speed, but if the overall spring
calibration is
substantially different (sounds like yours is) then you will still be
inaccurate at lower
and higher speeds than the set-point speed.
To get an idea of exactly how far off the actual gearig is would be to
drive
10 to 30 miles on an interstate with mile markers. Then compare the
odometer
mileage to real mileage. Then you can use the calibration number printed
on the dial face to estimate the proper calibration speedometer to use.
You can see a small treatise on this subject at my web page at:
http://ourworld.compuserve.com/homepages/arhodes
I'd be glad to help you more if you need it!
-Tony
Message text written by INTERNET:triumphs-owner@autox.team.net
>From: "James M. Amrine, Jr." <jamrine@home.com>
Subject: speedo/odo inaccuracy
I purchased a GT6 sometime back that had the rear end and rear body work
of a Spitfire. My problem is that the speedo shows a higher speed than
what I am really traveling (35mph= approx. 50mph on speedo guage). As a
result, miles are stacking up much more quickly than they should. I
believe the tires are roughly the size of the originals. Does this
require some kind of gear or something? Forgive me if I sound naive,
but I don't know much about how the speedo/odo work.
I know the rear end of the Spit has a different ratio than the rear end
of the GT6, but I would think (trying to use some engineering intuition
here, look out) that the speedo would read from the front end. I can't
seem to find anything in Haynes.
By the way, is Haynes the best manual out there or are there better shop
manuals for these cars?
thanks,
-Jamey
<
|