About Shock Shop
Hello and welcome to Shock Shop, my name is Chris Billings. In 1998 I retired from my mechanical consulting engineering practice. I had been racing reasonably successfully in SCCA national competition for several years and wanted to learn more about shock absorbers. I purchased a shock absorber dynamometer and began working with dampers for my own car. It was not long before word was out that I had a dyno and soon thereafter I was doing more work for other racers than on my own shocks!I found that I really enjoyed working with other folks and their projects. This led to setting up a hobby business ultimately named Shock Shop. It got more serious when I became a dealer for several shock companies. I attended seminars presented by these companies and made contact with others 'supposedly' knowledgeable with shocks. While they could teach construction, assembly and service, none could address tuning beyond claiming 'I / we know what you need'. Most would not even ask for any technical information about the vehicle! Having an engineering background, I knew there would be a better way.
In 2001 I created a routine for predicting damping forces for a road race car with the primary goal of reducing tire force variation, thus maximizing grip. I call this routine Critical Damping Analysis (CDA) and it is now in its seventh revision. I first used this tool to tune a pair of rear shocks for my own race car and gained nearly 2 seconds per lap at Portland International Raceway. In addition to better grip in the corners, I was also able to get power down much earlier coming out of the corners. Then I tuned the dampers for the front of the car and gained nearly another second per lap. Again, this was the result of better grip in the corners as well as on exit which further allowed getting power down early without understeer. I subsequently tuned dampers for many similar cars and those racers reported nearly identical results.
It is not uncommon to hear someone say that their car is different. Invariably, I disagree. The relationships between sprung and unsprung masses, rates and ratios are what govern tire contact patch behavior. So it is no surprise to me that, for over 11 years now, CDA has proven successful for a wide variety of cars including those raced on both asphalt road and oval tracks as well as on dirt oval tracks and off-road courses. Wins in all road racing classes which allow shock tuning, Dirt Late Model, Modified, Sprint and Midget classes have proven this. Unfortunately, tuning in many classes is still dominated by trying to find out and copy what the last winner did rather than using analytical tools. However, there are many racers successfully breaking from 'old school' methods and focusing on tuning their car utilizing a greater knowledge of their suspension and a properly tuned set of shocks.
For the last eight years I have greatly enjoyed serving as a suspension design judge in Formula SAE competition. In these events, sponsored by the Society of Automotive Engineers, colleges from around the world build a new formula race car every year and submit it to be judged in several categories and raced in several events. Though not quite formula one cars, most are very sophisticated, much more so than the majority of those cars in club and regional racing. The students are great to work with and many are already very sharp race car engineers, some seeking advanced degrees in the subject. It is also great pleasure to work with the other judges in the design competition, most of whom are engineers and very well respected, even internationally, for their knowledge of race cars and racing. I am especially proud of my alma matter, Oregon State University, which in 2011 proved that it has one of, if not the best, FSAE teams in the whole world! To learn more about FSAE you can visit this site:
SAE Collegiate Design Series