> Now that I'm running with the wrong wheels, tires, & transmission
> I need some sort of gearing in the speedo cable to get the speedo
> to read correctly.
> I'm sure those of you who do time / distance racing know exactly
> what I need and will be more than happy to help me spend $$$.
Well, if you're serious about TSD, you'll buy a special speedometer head
that can be calibrated to .01% or better. You'll still need to measure and
compute a fudge factor for distance at each event though, since the diameter
of your tires is by no means constant. Steve Hedke has a really nice one in
Scrappy, it makes two full turns to get to 80 mph, each mph is about 1/4" on
the scale ... I didn't even bother asking how much <g>
However, if you want to keep the original speedo and aren't quite so
fanatic, any speedometer shop should be able to make up a ratio box to go in
the speedo cable. I was quoted $100 for the box, including installation and
any necessary cables. Subsequent ratio changes (like for different tires)
would only be $40 installed. However, I haven't done it yet, as I've more
ratio changes planned and need to get the speedo head reconditioned first.
Randall
|