* Using your Tach as a Speedo *

["Wayne Brazinski" <wayne@brazinski.com>]

Hi Everyone!
Took the 3A out twice today - as fast as I dared.  Damn what a good time.
Since my speedo needle does not move until 40mph has been exceeded, and when
it does move it is almost totally random, I would like to guess how fast I'm
going from the tach (until I get it repaired).

>From what I have been told - if I have the 3.9 diff gear ratio I simply
double the first to digits of the RPM - so 3,000 equals 60 mph, and 4,000
equals 80.

So - is this correct?

I also have a TR4 O/D in the car - so I'm hoping to guess using this as
well!

Thanks in advance.

Wayne