Project 240 - Autocross

February 5th, 2006 Gainesville Raceway Autocross

The analysis techniques and data presentation are improved over the October 2005 event. Animations of the GPS and acceleration data in the video help recreate portions of the race. A simple technique to estimate the vehicle performance limit is presented and applied to the GPS ground track plot. The visual feedback from this combination is quite useful for quickly assessing the driving technique.

October 23rd, 2005 Gainesville Autocross Data:

A brief analysis of the GPS, accelerometer, and control input data from the Buccaneer Region Solo 2 autocross event at the Gainesville Raceway. The event was held on October 23rd, 2005. Standard techniques are used to present longitudinal acceleration data on the GPS ground track plot. Joint acceleration probability is presented for each of the four accelerometer measurement locations.

Project_240 - Video release 3 - Low quality WMV [4MB]
Project_240 - Video release 3 - High quality MPG [16MB]

Project_240 - Video release 4 - Low quality WMV [13MB]

Release 3 is less of a drift test and more an experiment with various camera angles during a series of autocross runs. A small camera based on the new Sony 1/3" CCD array is positioned throughout the 240SX to capture the short run from many perspectives. The title of the video, 'Reflections on Racing' suggests that many of the shots intentionally made use of surfaces that had both reflective and translucent properties. For instance, the sunroof angle makes use of the ambient light and the dark car to show the reflection of the clouds and sky as a (somewhat) subtle backdrop to the overhead view of the driver struggling to avoid cones. Other angles experimented with side-reflections (see thumbnail above) to achieve converging or diverging horizons, depending upon the turn direction. A single audio track (from the internal camera) is used for the on-board shots to maintain continuity.

Release 4 is a much longer version of the autocross multi-camera video experiment. The individual camera angle clips are extended to show most of the autocross lap for each view. Additionally, the original audio has been replaced with music from the 1980's game Outrun.

Brooksville AutoX Chase Camera Video List
Brooksville AutoX Chase Camera Images

The next best thing to actually racing an autocross circuit is speeding behind the racer in a chase car taking video and pictures! The top link contains a list of at least one video from each of the 20 competitors who participated in the Sunday Double-Points Action Plus Series (not the formal name). Some extra videos have been added based on novelty or request. I will gladly humor requests for specific videos from racers or participants, just let me know what you'd like me to post. Note that only 65% or so of the runs were actually recorded on video.

The bottom link goes to the 262 images taken with a still camera.

A brief shout-out to Anthony Adams (#15), Jerry Epperly (#74), Abhishek Shinde (#24), and the two unknown (sorry) guys for driving the chase car, picking up cones, or helping with the video shooting.





						Autocross I have been autocrossing since October 2004 as an expanded part of my Project 240 experiments. Autocross is great way to experience high-performance driving and is a good exposure to car response at the limits of acceleration and adhesion. My initial goal from racing was simply to improve my capabilities as a test driver, but continued participation resulted in thoroughly enjoying the competitive atmosphere. Autocrossing is obviously very different from drifting and often the objectives of the two and required driving style are contradictory. However, the ability to quantify racing performance, both in an elapsed time and in an acceleration sense, make it quite appropriate as an additional focus of the research. The content on this page attempts to understand through experiment the dominant factors affecting autocross performance.