I meant to add that third gear times running from about 2000 rpm to readline
will also work. Do it on a flat, and average the time from runs in both
directions. Your speedometer is adequate as you are only looking for relative
changes. I find that a small voice recorder (not voice activated) can be used
to record as you call out the start times and the point at which intermediate
speeds are reached. Then go back and rerun the tape using a watch or timer to
get the best data you can. Not worth cracking up to read the timepiece!

Frank Grunthaner