This past winter I replaced the 4.22 diff in my Bugeye with a 3.9 - a change
I am very happy with. Of course, that meant that my speedometer and
odometer, of course, were no longer accurate. I found a fellow who makes
"ratio adapters" to correct this problem. I had to drive the car over a
known distance (the longer the better) which in this case was 16 miles. I
noted the odo reading on the car, which was 14.8 miles, and provided this
information along with a speedo cable. He cut the cable (I was able to tell
him where, it worked well about 6 inches from the gearbox end), and inserted
his adapter which is a little box not dissimilar to the tach drive on the
back of the generator. Inside are 4 gears, which together make the
correction to the cable speed. I installed it all, and ran the car over the
same course, and voila! 16 miles. This will work for any inaccuracy due to
diff ratio, tire size, whatever, and he can do it for any mechanically
driven speedometer.
Doug Ingram
Victoria BC
1958 Sprite (AN5L/636)
1963 Sprite Mk II project (HAN7L/30003)
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