following excerpt was written by:

By Dr. Jeremy Torstviet

 National Dragster Sept 18, 2009

 

I was happy to represent the drag racing community at the annual International Council of Motorsport Sciences (ICMS) meeting, held July 28-30 at Indianapolis Motor Speedway.  As usual, the topics were widely varied and well-presented.

 

Tire shake presents potential serious injury

The highlight of the conference was Trevor Ashline's presentation of the research conducted on side-to-side vibrations (tire shake), and the subsequent modification to the driver's compartment and driver restraint systems that followed.  I discussed some extrication issues during this presentation. 

Until the tragic death of Eric Medlan, tire shake was considered a run breaker and a headache producer.  John Melvin, Ashline (Safety Solutions Inc.), Kris Van Gilder (ISP Seats), and Dr. Paul Bergman (Wayne State University) reported their work in an SAE paper in 2008 but had already made major changes to the driver compartment and restraint system, which proved successful in preventing head injuries in a similar accident.

Also reported in this presentation was the remarkable improvement in had and neck restraint systems since the original devices were employed.  Safety Solutions created a new design that has remarkably reduced G forces in straight-line crashes and, by adding lateral tethers, has dramatically reduced angular G forces, which cause more brain damage than head-on crashes.  Drivers who need more side-to-side mobility can opt for a sliding tether system.  This, combined with custom cage padding, a change in seat configuration, and a change in number and mounting of the belts, has made a major reduction in stress forces to which the driver would otherwise be subjected.

What I like the most is that the improvements were first tested in the lab, then proven on the track.  I was a strong proponent for adoption of head and neck restraint systems when they first were developed but had some reservations about the system "hanging up" the driver during extrication or exit from the car; this has occurred several times. once during a funny car fire.  Safety Solutions' system avoids this problem by having a low profile, and according to several drivers, it is much more comfortable than the old-style system.

 

Cost of equipment and the sportsman racer

Professional racers should update to the new equipment.  Sportsman racers in some of the Comp cars are already required to wear a restraint device, but low-budget teams with slower cars should consider skipping a couple of races to get a cockpit restraint makeover.  My fellow back-page columnist and Sportsman racer Bruce Deveau has voiced concern to me about increasing tire shake problems in some of the "slower" classes, and considering how powerful many of these cars have become, this shouldn't be surprising.

Door car drivers should consider getting driver restraint nets like the one used by Jeg Coughlin and others.  I doubt they will become compulsory in all classes, but remember that safety specs are minimal requirements.  Do yourself a favor and get a consult from Safety Solutions (800-731-4404); Web site, www.safetysolutionsracing.com).  The company has your cost concerns and special drag racing needs in mind.  It's the whole package that needs to put together and be individually tailored to each driver.