Originally Posted by racecrafter

everything that has been said above works, to a point. along with the access problem you spoke there are some other issues.
If it is a four link car and you are running as soft a spring as you should then maximum shock travel will probably come somewhere other than when you are making a pass, like return road, pits, or that nice little dip you go through before you do your burnout. Besides the really usefull information comes from being able to see what the shock is doing throughout the whole run. If you have a data logger that gives you enough info to determine tire slippage and also allows the addition of a shock travel sensor you will see some interesting things going on not just at the initial hit and gear changes but also throughout the run. This can be a very valuable tuning aid but........aint cheap.....short of this I would recomend some high speed video shot from the rear, 3/4 rear and side in as many places on the track as you can but at least the first 60 feet this will tell you more about what is going on back there than something that just tells you how far the shock moved since the last time you reset the telltale