64ft Times

Timekeepers at speed events usually set up additional sensors to record the time taken to cover the first 64ft off the line, and a speed trap on the fastest part of the course. The value of a speed trap is obvious enough, but what can be learnt from the 64ft time?

Clearly, cars with the best power/weight ratios should achieve good times, but more importantly it’s an indication of the level of traction achieved. The more wheelspin, the slower the acceleration, so the 64ft time enables the driver to check the impact of variations in starting technique. A lot also depends on whether you change up a gear in the first 64ft – if your first gear takes you past the sensor you’ll post a better time. The choice of 64ft may have something to do with the fact that a time of 2.0secs equates to an acceleration of 1g – an alluring target to aim for!

Here are the figures in graphical form, if you prefer:

So shaving a tenth or two off your time in those first few crucial feet could make the difference between a class win – or not!

PS This table illustrates the theoretical speeds achieved for different 64ft times, assuming constant acceleration. Make of it what you will!