triumphs
[Top] [All Lists]

Re: [TR] TR3 Speedometer Calibration Graph

To: <triumphs@autox.team.net>, <wsb1960tr3a@att.net>
Subject: Re: [TR] TR3 Speedometer Calibration Graph
From: Mo and Dave MacKay <m.d.mackay@sympatico.ca>
Date: Thu, 11 Apr 2013 17:22:40 -0400
Delivered-to: mharc@autox.team.net
Delivered-to: triumphs@autox.team.net
Thread-index: Ac42+rBTq94lu8zfTpSpIrALYCmUQw==
Bob Danielson has an excellent write-up on his web site:
http://tr6.danielsonfamily.org/SpeedometerCalibration.htm

I created a little spreadsheet that calculates the speed at any rpm in a
particular gear when I was contemplating installing the HVDA conversion in
my TR3A.  I'd be happy to send it to anyone on the list who might find it
helpful.

After installing the HVDA transmission, I found myself routinely speeding so
that I figured I'd better re-calibrate my speedometer. I sent my speedometer
to Margaret Lawrence at Mo-Ma in New Mexico. She charged US$150 to
recalibrate the speedo and had it back to me in about 2 weeks. I'm happy
with the work that Mo-Ma did.

In order to calibrate the speedo, Mo-Ma needed to know how many revolutions
the speedo cable makes in a mile. My speedo was set for 1184 revs per mile.
To determine what the revs are now, I measured out 59 9= (1/100 of a mile)
on the road in front of my house. I marked the wheel and pushed the car over
that distance to see how many revs the cable made. I repeated that 4 or 5
times. I came up with 10 complete turns and a partial turn of about 215
degrees, which works out to 10.5972 speedometer cable turns over the 52 9=
distance. Consequently, I asked Mo-Ma to calibrate my speedo for 1060 revs.

Regards,

Dave MacKay

1960 Triumph TR3A
s/n 68639L
near Toronto, Canada

>Message: 7
>Date: Thu, 11 Apr 2013 08:05:13 -0700 (PDT)
>From: William Brewer <wsb1960tr3a@att.net>
>To: Triumphs <triumphs@autox.team.net>
>Subject: [TR] TR3 Speedometer Calibration Graph
>Message-ID:    <1365692713.60557.YahooMailNeo@web180904.mail.ne1.yahoo.com>
>Content-Type: text/plain; charset="us-ascii"
>
>     Is there an online pdf for the calibration for a TR3A speedometer with
>overdrive? I would like to do a check of rpm's verses speed indication.
>
>TIA,
 >
 >    Bill in Tehachapi

[demime 1.01d removed an attachment of type application/vnd]

** triumphs@autox.team.net **

Archive: http://www.team.net/archive

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