Drift

There's a chart in this post that should help:

http://www.pinewoodderbyonline.com/post/Tune-Table-Question-6360833?highlight=drift+chart

Look at post #8 in the link
 
So cool that our cars got to go down right next to each other so many times. It's amazing to think that .004 seconds is only about an inch and a half difference on the track.
 
Eliminator, by the chart it appears that a 3" drift in 4 foot equates into 12" over 8 foot, in case you haven't had a chance look at the chart yet.