For racing, we've added a HotLap timer from Longacre, and are experimenting with a G-Cube from Extreme GEEZ. The HotLap timer is invaluable; it automatically captures the time for every lap (up to 60 laps) and displays a lap count and the time for the most recently completed lap to the driver.
The G-Cube, along with a Palm computer, captures lateral and logitudinal acceleration. The data can be uploaded to a PC, where associated GEEZ software calculates velocity and other data and displays graphs and a map of the car's path through the course.
However, GEEZ is really intended for autocrossing, and it doesn't do laps on road courses very well yet. Because of this, we're also experimenting with GPS for data collection. This generates much more reliable velocity and car path data, but the frequency of data collection is not yet high enough for optimal results.
We started with an old Delorme Tripmate GPS receiver, which captures data only every 2 seconds, but now have acquired a new Garmin receiver which captures data every second. Nate has written software which interprets the data and displays it in a very useful way. Once we've experimented more, we may make this software available.
See also the Suspension page for information about the extensive reworking we did to improve the car's handling and cornering on the track and street.