David:
When you switched from 1000 to 950 on the KMH speedometer to get a more
accurate speedometer, was that with the OEM tire size, or was your
speedometer inaccurate (reading low) because you had switched to taller
tires?  Like
Budd, I am having a problem with the math.

Cary

----- Original Message -----
From: David Marshall <vanagon@VOLKSWAGEN.ORG>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, May 21, 2004 9:43 AM
Subject: Re: Syncro Speedometer

> Yes, I have done this for one of my Syncros - 950 vs 1000 for the KMH
> speedometers - you have to change the face plate along with it, but not a
> big job.  I did this to get a more accurate speedometer and a face that
> matches the Jetta II Diesel tach I installed.
>
> Just make sure you use a VDO and not a Motometer speedometer - swapping
the
> back plastic housing is all that is required.
>
> David Marshall
>
> Fast Forward Automotive Inc.
> 4356 Quesnel-Hixon Road
> Quesnel BC Canada  V2J 6Z3
>
> http://www.fastforward.ca    mailto:sales@fastforward.ca
> Phone: (250) 992 7775        FAX: (250) 992 1160
>
> - Vanagon Accessories and Engine Conversions
> - Vanagon, Transporter and Iltis Sales and Importation
> - European Lighting for most Volkswagen models
>
>
> Due to the large volume of email  we  receive,  PLEASE  include  previous
> emails when responding.  This will allow us to read the complete dialogue
> in one message and will result in quicker and more  accurate  responses.
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]On Behalf
> Of Budd Premack
> Sent: May 21, 2004 12:39 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Syncro Speedometer
>
>
> Can a Jetta speedometer with the ratio 1540 be substituted for a Syncro
> speedometer with the standard 1600 ratio?  If so, will the typical 4% low
> speed reading be altered to about 8% low, or will it tend to correct to
> close to an accurate reading?
>
> My rusty math and high school physics concepts suggest to me that if the
> replacement speedometer had a ratio of 1664, the common 4% low error would
> be corrected.
>
> (1600-1540) / 1600 = 3.75% fewer revolutions (?)
> (1664-1600) / 1600 = 4.00% more revolutions (?)
>
> BTW, does anyone have a spare Syncro speedometer?
>
> Budd Premack
> 86 Syncro, 88 Wolfsburg
> Land of Sky-Blue Waters
> Minneapolis, MN
>
>