#ShockAbsorbers

It’s taken a while to get started on the project to make my daily driver Saturn SL1 into a better handling car. I had the parts but it took a few weeks to be able to get the work scheduled at a shop that was willing to install my own components. Now that the work has been done and I’ve been able to drive the car in varying conditions, it’s time for a progress report. The short version is that I’m pleased with the results. For the long version, continue reading after the break.

ZF Friedrichshafen AG and Levant Power Corp., a Woburn, Massachusetts technology company spun off from MIT, have announced what they call the first fully active suspension system that includes a regenerative function that recovers energy from the motion of the suspension. The system is branded GenShock. Active suspensions are not new, General Motors experimented with an actively suspended ZR-1 Corvette when the automaker owned Lotus, which had worked with active suspensions before the technology was banned in Formula One. Going back even farther, there were the hydropneumatic Citroens and the last true Packards’ “torsion level” suspension. With road cars the goal in using such a system would be to combine good ride with good handling, soft sometimes and stiff sometimes, depending on the driving circumstances. Early tries at developing what chassis engineers call a “high bandwidth active suspension”, capable of dealing with those varying circumstances, have run into cost, complexity and power consumption issues. The GenShock system is claimed to be affordable, simple to integrate in existing suspension designs, and not only have modest power consumption but also be able to recover energy from the suspension.

In times like these, folks keep their cars longer (just ask Comrade Fidel’s oppressed masses of loyal subjects). Unfortunately, faster-spinning odometers have the nasty side effect of more quickly chewing up your car’s normal wear items. Some of these components (like brakes) can get downright demanding as they die. Others, like shock absorbers and their MacPherson strut cousins, just blend into the woodwork and stay there. Much like the guy in your high school yearbook that you can’t remember, your vehicle’s shocks and/or struts get Rodney Dangerfield-levels of respect and even less attention. Symptoms of worn shocks or struts include excessive floating after traversing even small bumps in the road, greater-than-normal body roll during cornering, increased braking distance, and extreme front end dive under moderate-to-hard braking.