COLORADO ZR2
orifices through which the oil flows, Mutlimatic can fine-tune the spool valve’s response to varying input speeds. It’s the same sort of thing that electronic suspensions (such as GM’S own Magnetic Ride Control) do, except the DSSV is entirely mechanical.
Multimatic developed the system for racing, and it was later applied to street cars, starting with the 2014 Chevrolet Camaro Z/28. Since then, the Aston-martin One-77, Ford GT, and Mercedes AMG-GT have adopted DSSV shocks. Road cars that use DSSVS have shocks with two spool valves; one controls compression and the other controls rebound, which allows the two motions to be tuned separately. This gives them a distinct advantage over shim dampers, which effectively have a single valve; changing the compression characteristics also changes rebound characteristics.
The Colorado ZR2 features the first application of DSSV shocks in an off-road truck. At GM’S request, Multimatic developed a unique shock absorber with three spool valves. The first two DSSVS are responsible for compression and rebound damping, as in a roadgoing DSSV shock. But the real magic happens once you get out in the dirt and start pounding the daylights out of your ZR2. As the damper shaft passes a given position—about halfway through its travel—bypass valves in the main body allow oil to flow to the third spool valve, which is optimized for high speed operation over rough terrain. The front shocks also have a shim valve at the bottom of the main damper body to provide a smooth landing should the suspension drop to its full extension—in other words, if you get the truck into the air. And as the photos show, we got the ZR2 into the air. Repeatedly.
That said, the fact that you can defy gravity in the ZR2 without bending anything important is not the really amazing bit; after all, given the right set of shocks, any truck can be a jumper. No, what sets the ZR2 apart is how well it does everything else—specifically, its on-road ride and handling. Before Chevrolet set me loose on the trophy truck track, I had a long drive in a Colorado Z71 4x4. After our flying adventures, we took the ZR2 out for an even longer drive. Know what? The ZR2, which is obviously the superior truck off-road, is also better on-road. It has a smoother, steadier ride than the Z71, and it spares you the constant bouncing and floating