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If you eye up Chevrolet’s new Colorado ZR2 pick-up, you might spot a glint of gold coming from an unusual-looking damper with the word ‘Multimatic’ stamped on it. It’s not a conventional damper, nor is it an adaptive one. So what the hell is it, and how does it work?
While at the LA Auto Show, we were whisked over to a special off road course in one of those impossibly large SUVs our American friends love, to get a passenger ride in Chevy’s new hardcore off-roading truck and find out a little more about the damper tech.
The work of Canadian firm Multimatic, the DSSV (Dynamic Suspension Spool Valve) damper system is something you’d usually find on a supercar or racing car. It’s been used in Formula 1 and the World Endurance Championship, as well as the Aston Martin One-77, the base Mercedes-AMG GT and the fifth-gen Chevrolet Camaro Z/28.
The spool valve is the crucial piece here. It replaces the metal shims which you’d find covering the holes in the damper’s piston, which move out of the way when the large amounts of force are applied through the damper, allowing oil to flow more freely and thus the piston to move to a greater degree.
The Multimatic system replaces this with a little spring loaded spool valve, with a ‘keyhole’ to let fluid through. It’s the keyhole that’s the crucial bit, as the size and shape can be altered to control the characteristics of the damping depending on how much force is put through it. In other words, it can be firm or soft when it needs to be, acting like an adaptive damper but with passive technology.
It also gives more consistent damping than a shock absorber with shims, is stronger, and much better at heat management.
The ZR2’s application of the system is where things get really interesting. It’s the first time the technology has been used for an off-road vehicle, which means it’s used slightly differently here. There’s a pair of spool valves in a remote chamber - one for compression and one for rebound - as in all other DSSV dampers, but with an additional third valve mounted on the piston, giving additional damping during hardcore off-road driving. This is known as position sensitive damping.
Finally, you get separate rebound valves for the front dampers, which come into play when the suspension is fully extended. The reason? So you can do a ruddy great jump and land safely without doing a massive endo. Useful, no?
This is all well and good, but why not use an adaptive damper system instead? Multimatic told us that heat build up would be an issue with an adaptive system in an off-road application, but also, there’s the extra weight, complexity and fragility of adaptive dampers to think about.
I was sent around a short off-road course in a ZR2, and while my inner cynic wants to point out that Chevrolet wouldn’t design a course that shows up any of the hardcore Colorado’s weaknesses, the pick-up did seem to handle the course impressively. In particular, I was expecting a series of offset bumps at the beginning to be massively uncomfortable, but I was surprised just how smoothly the truck demolished them.
Needless to say, we’re pretty keen to take a drive and see how this tech handles the really rough stuff.