One of the projects for the vehicle dynamics section of the test track was one that seemed so obvious – and proven wrong. The National Highway Traffic Safety Administration was convinced that worn-out steering and suspension components of cars would markedly reduce the ability of the driver to control the car. CAL began a project called Steering and Suspension Degradation. We drained enough fluid from the shock absorbers to make them weak. As a former chief engineer manufacturing suspension hardware, I knew how to make tie rod ends and ball joints loose and sloppy. We put those parts in the steering linkage and the front suspension of our two test cars.
We set up several test courses outlined tightly with traffic cones. We used the double lane change AM test developed for General Motors. We also set up two 90 degree J-turns outlined narrowly with traffic cones out on the skid pad. We got another surprise! All the drivers quickly learned to compensate for the sloppy steering. Test speeds, with experienced drivers, stabilized close to that of un-degraded cars. We learned that running the test repeatedly gave us plenty of time to compensate. That explains why so many junker-cars are still running on the roads.
Well, come on – what else could we do for an experiment? How would it be with the worn out shocks and suspension ball joints when the car is on a bumpy road? CAL had a tight-radius paved curved section on the VERF that we seldom used. It had a long straight section leading into it. I was sure that CAL would not want me to tear up the black top paving to make a rough bumpy path. Then I recalled those long extruded strips of rubber made at Uniroyal. Those were the treads that an operator wound around the mandrel when building a tire. I called my friends in Detroit. Could Uncle Sam (CAL) buy about 60 pieces of the thick tire tread rubber cut into twelve foot long chunks? Could you cure them (heat them so the rubber was set) flat rather than as hoops? Sure.
Hot dog! Now I had portable rubber bumps to spread out on any test track. Scattered at random, with carefully measured spacing on our tight curve, we had a reproducible rough road. Better, it would not wear out. Rough broken pavement eventually turns into gravel. Not our road.
OK – now we were ready to show the NHTSA how degraded cars would suffer on a bumpy road. We ran our worn out cars around the un-bumpy road with each driver to find the maximum speed we could do it without leaving the pavement. I spread out the rubber strips. The drivers, including me, ran again. Another surprise! Our wrists hurt from the experience, but we could still match the previous speeds. How come? We got our crash-test movie camera crew to set up for some close-in high-speed motion pictures of the wheels near the ground level. Sure enough – all four tires were up in the air briefly and rapidly. So why didn’t the car go flying out off the curve while it was in the air? Get back in and do it all over. This time CAL put a camera inside to watch the steering wheel. Some small strips of white tape on the rim made it easier to observe the driver’s behavior. Ah-ha! That’s it. We steered to a larger angle after we entered the bumpy curve than when the road was smooth. Oh – the car was moving out a fraction each brief time it was in the air, but the sharper steering brought it back on course when the tires landed again. We never went off the pavement until we were just plain going too fast.
That was yet another victory for the ability of the driver to quickly compensate for degraded performance. The learning curve was just in the first few feet after entering the bumpy section. That was the end of that government program. Thank goodness we prevented Uncle Sam from promulgating useless new standards. What we did establish was that degraded drivers, under the influence of alcohol, were a much greater threat than worn out cars.
NEXT: Crasher Carl
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